1
www.astronomy-wise.com
2
Editors Note….. Welcome to the February 2013 Astronomy Wise EZine. I hope you all enjoyed any Stargazing Live events you went to. This month we have the return of Lets Talk our monthly interview slot, and I am pleased that this month we have the Meteorite Men.
Editor: David Bood Twitter: @AstronomyWise www.astronomy-wise.com davebood@gmail.com
Astrophotography is becoming more and more popular and accessible to the amateur astronomer. Mike Greenham continues looking at imaging the skies with a look at deep space objects with a dslr camera. We have our monthly ’The Night Sky’ with John Harper F.R.A.S our guide to what to observe during the month. We are also going to look at Polar aligning with different mounts, Mike Greenham and Ralph Wilkins from Active Astronomy provide the help. This month I am having a look at easy to find objects in the night sky, starting off with The Plough or the Big Dipper as it is known in North America. The Astronomy Wise team was out in the community helping St Marks Brownie pack (Scarborough) with their stargazing badge. January 11th Astronomy Wise held it’s first of the year public stargazing nights inline with Stargazing Live.
Front Cover Photograph Photograph by Suzanne Morrison © Aerolite Meteorites, LLC Design Edward Dutton & Robert Watson Occultation information Plekhanov andrey
www.astronomy-wise.com
3
Meet The Team
Jason Ives co founder Events organiser, Rouges Gallery, writer
Writers
David bood co founder Magazine editor,writer Edward Dutton graphic design, adverts, t shirts
John Harper f.r.a.s Sky notes, articles, advice, public speaking
New competition see page 16 for details, you must read our interview with the Meteorite Men to get the answer. Contact Details Rouges Gallery: astronomywiseimages@gmail.com Design: astronomywisedesignteam@gmail.com
www.astronomy-wise.com
4
www.astronomy-wise.com
5
www.astronomy-wise.com
6
Lets Talk‌ This month we have an interview with two guys from across the pond. They have featured in their own hit TV shows, written books and featured on Science programmes. So I am pleased to introduce Geoff Notkin and Steve Arnold best known as the ‘Meteorite Men’.
AW: For those people who are new to Astronomy and looking up into the night sky could you please tell us what exactly a meteorite is and how they get to Earth? GEOFF: Meteorites are cosmic debris that have fallen to our planet from outer space. As far as we know, all recovered meteorites originated within our solar system, and the vast majority of them come from the Asteroid Belt. A comparatively small number of meteorites are of lunar and Martian origin and it is possible that a very few are remnants of comet nuclei, but that is only a theory at present. Most meteorites are rich in iron and nickel and there are a few minerals that are unique to meteorites. AW: Steve and Geoff how did you become interested in Meteorites? STEVE: I became interested in treasure hunting and metal detecting about 21 years ago and purchased a book on the subject. During my research I came across a story from 1890 where a lady sold a meteorite she found to the University of Kansas. That got me thinking to myself, "If meteorites were worth money over 100 years ago, are they still worth money today? And do they have metal in them so maybe a metal detector could find them?" The answer to both questions I asked myself was "Yes!" I began researching, hunting for, finding, and selling meteorites, and I never quit. GEOFF: My father was a keen amateur astronomer and, even as a little boy of six, I was an avid rockhound -- always scrambling around in quarries and on cliff faces, looking for minerals and fossils. I first encountered meteorites when I was about seven years old, during a visit to London's Geological Museum with my mother. It was something of an epiphany; here were strange rocks from outer space that www.astronomy-wise.com
7
were, to my wide eyes at least, very clearly a marriage between astronomy and geology. Looking through telescopes at stars and planets was fascinating to me, but this was one better: I was able to actually touch the fabric of another world. That wonder and fascination simply never left me. AW: How did you guys link up? STEVE: Back in the early days of the Internet, I did a search among AOL members and I found about eight people with the word "meteorite" listed in their profile. Before the word "spam"
was coined, I "spammed" all eight of them, and one guy who responded was Geoff. We struck up a friendship which lead to us meeting in person for the first time at the Santiago, Chile airport. Off we went on a two week excursion into the Atacama Desert in search of meteorites. What would have driven most new acquaintances far apart, seemed mysteriously to bind our friendship together. Anyone who wants to know more can read all about that adventure in Geoff's new book, Rock Star: Adventures of a Meteorite Man
AW: How do you find meteorites which are buried? What equipment do you use? GEOFF: Since most meteorites contain anywhere from about 20 to 97% iron, we employ sophisticated metal detectors to search for buried pieces. Of course, our detectors also pick up anything else that contains iron, so we have literally excavated piles of nails, bullets, barbed wire, horseshoes, old farming equipment, tools, cans, and stumbled upon more than one unexploded missile. That keeps it interesting. If we are hunting in a zone that we believe has meteorites buried less than a half meter, we will use hand-held detectors, and particularly favor Fisher Labs, Teknetics, and Minelab. More deeply-buried masses require a larger detector and different technology. Pulse Induction detectors by PulseStar and Lorenz can be used with much larger electromagnetic coils that can "see" further into the ground.
www.astronomy-wise.com
8
AW: What is the largest meteorite you have found?
on Earth where those space rocks remain preserved and are able to survive until they are found. I'm STEVE: On October 17, 2005 I referring to deserts where there is discovered a 1,430-pound little moisture and fewer freezing pallasite buried 7 feet 4 inches and thawing cycles. In a dry below a Kansas wheat field in climate the meteorites don't rust or Brenham township. break down as quickly as they do in other climates. It is definitely GEOFF: Yeah, Steve definitely easier to find meteorites where holds the record for our work. Not there is less competition to locate only was his big pallasite find one them. This would include the ice of the largest meteorites found in fields of Antarctica, deserts, dry the United States, it is also the lake beds, and farm land with few largest oriented pallasite ever or no terrestrial rocks allowing found oriented meteorites being farmers to hit them with their those that have acquired a rounded plows. Also, locating the "bullseye" or cone-like leading edge as a of a fresh meteorite impact result of ablation during flight. We dramatically increases the odds of found seven hundred pounds of finding some and often they can meteorites while making the be visually spotted rather than Meteorite Men pilot, and have requiring the use of a metal recovered space rocks on four detector. continents. AW: What is the most rare AW: I can imagine most meteorites meteorite have you found? fall in to the sea, where on land would you say most meteorites fall? GEOFF: We have been particularly successful working with pallasites, a beautiful meteorite type that is STEVE: Statistically speaking, mecomposed of approximately 50% teorites randomly fall pretty evenly all over the globe. There are, however, places
www.astronomy-wise.com
9
nickel-iron and 50% olivine crystals. In a pure form, olivine is known as the gemstone peridot. There are currently almost 45,000 different recognized meteorites and of all those, there are only 95 pallasites. We have found numerous examples of three different pallasites: Brenham (Kansas, USA), Admire (Kansas, USA), and Imilac (Atacama Desert, Chile). Another find of particular note was the rare mesosiderite Vaca Muerta from Chile. Like pallasites, mesosiderites are stony -iron composites, but are rich in pyroxene and feldspar, and do not display large crystals. We found a complete 3.4-kg mass in 2010 and two prominent meteorite experts said it was the finest example of a mesosiderite they had ever seen. Some of our other finds have displays usual features that were of great interest to meteoriticists and a number of scientific papers have been written about meteorites that we have recovered. AW: Can you tell us about your websites? STEVE: I am excited to announce my brand new Smart Phone APP which allows people to access all things meteoritic, including our Meteorite Men site, with just a few taps on their phone screen! The Meteorite Smart Phone APP can be found at: http:// www.1tap.mobi/arnoldmeteorites My wife, Qynne, and I recently opened America's only brick and mortar meteorite store in Historic Downtown Eureka Springs, Arkansas called Meteorites and More. I know it is "low tech" and is bucking the flow of everyone else on the planet who seems to be leaving downtown and going online, but it allows us to reach out and share the "awe of the cosmos" with tourists who come to this quirky town. www.astronomy-wise.com
10
In addition, we still sell a lot on EBay. GEOFF: One of the great things about Steve is he's always pushing the boundaries of technology and looking for new and better ways to do things. I think it's just great that at the same time he's developing a groundbreaking meteorite app, he also opens a store in weird and wonderful Eureka Springs. I like to think of that as a kind of converse strategy approach to business. We make a good team because Steve is an ideas person and I'm a media person. In addition to being a meteorite specialist, TV host, and amateur astronomer, I am a science writer, art director, publisher, and photographer and, together with my publicist Becca Gladden, manage our public relations and web presence. I designed and built the official website for our television series www.meteoritemen.com and I manage our social media presence on Twitter www.twitter.com/ meteoritemen , Facebook www.facebook.com/meteoritemen , and Pinterest www.pinterest.com/meteoritemen . We are very active on Twitter and I also have my own account www.twitter.com/geoffnotkin . I find Twitter to be an extraordinary resource for connecting with like-minded science and astronomy enthusiasts and I warmly invite all tweeps among your readers to connect with us. I am in the process of collecting all of the best Meteorite Men interviews and articles on our Pinterest site, and it's been interesting and enjoyable to revisit some of the features we've done over the years. My flagship website is dedicated to my commercial meteorite company, Aerolite Meteorites, LLC www.aerolite.org . We are one of the leading suppliers of quality meteorite specimens and have worked with most of the world's leading collectors and institutions and we are always happy to advise and assist new collectors. We also maintain a private mailing list http://www.aerolite.org/admin/mailinglist.htm and send out a monthly newsletter with details about our expeditions, television work, and new meteorite acquisitions.
AW: Can you both tell us about your tv shows? A little bit about behind the scenes. GEOFF: Our very first television show about meteorites was an episode of The Best Places to Find Cash & Treasure for the Travel Channel. We found numerous space rocks at two different locations and were advised by the network that it was the highest rated episode out of the www.astronomy-wise.com
11
entire series. We went on to work with Wired magazine and PBS on the pilot of a science series called Wired Science. It was a successful show and ran for several seasons. We have also worked with TLC on American Chopper, National Geographic on Naked Earth: Our Atmosphere, and Discovery on Cosmic Collisions. We are, however, best known for our three seasons of Meteorite Men, which aired on Science in the US and Discovery Networks around the world. At present, Meteorite Men is showing in 27 countries and has introduced millions of people to meteorite science and meteorite collecting. We filmed on four continents and travelled about 120,000 miles while making the 23 episodes. It is the first and only television series about meteorites and has generated a tremendous amount of interest, worldwide, in a previously little-known scientific discipline. We
worked with many different directors and producers and it is interesting to see how different creative teams bring their own vision to an existing series. Some producers were more interested in the adventure and treasure hunting aspects of the show, while others made episodes with more scientific content. During the first season, we were amassing about 65 hours of footage for each episode. In American programming, if you take out all the adverts from a one-hour show, you are left with 43 minutes of air time. So, every broadcast minute was edited down from about 1 1/2 hours of footage. That means there are a ton of great outtakes and bloopers in the archives and we hope some of them will see the light of day in the future. AW: If someone was interested in collecting samples of meteorites what sort of price would be a good starting point? (ÂŁ or $)? STEVE: I strongly suggest people keep their first purchase reasonable enough that they won't be tempted to sell it if financial troubles arise in their future. It would not be good to struggle with the temptation of selling off your "first meteorite" just to pay a bill. Hock your second or third, or 1,000th meteorite, but not your first one. It's just too special!
www.astronomy-wise.com
12
AW: Apart from featuring in "Astronomy Wise" (lol my little joke) what are the highlights of both your careers? STEVE: While there were many significant events throughout my career and many that directly led up to the pilot episode of our TV series, Meteorite Men, it was the production and airing of the Meteorite Men pilot which was the most significant of my career. It was significant not only in what it did for me personally, but in what I was able to give back to the meteorite community and in what I was able to share with the public at large. GEOFF: Either individually, or as a team, Steve and I have appeared as invited speakers at the Northeast Astronomy Forum (NEAF), The USA Science & Engineering Festival in Washington, D.C., Stellafane, Challenger Space Center Arizona, National Metal Detector Day, Lowell Observatory, the Arizona Science & Astronomy Expo, and many other events and venues. I greatly enjoy the opportunity to share my passion with science-friendly audiences. Making the first season of Meteorite Men was definitely a high point for me. We worked with some extremely talented people and filmed those first six episodes quickly and efficiently with a small and very capable crew. The first season had an almost guerilla-like feel to it: we were constantly on the move, switching locations at the last minute due to bad weather, thinking on our toes, and finding meteorites, or course, and it was all very exciting. In Season Two we had the extraordinary opportunity to work at the Henbury Craters Preserve in Australia, and that was a dream come true for me. I find Henbury to be one of the most fascinating places on the planet, as there are fifteen well preserved meteorite craters in very close proximity to each other. The publication of my autobiography, Rock Star: Adventures of a Meteorite Man, in June of 2012 was another big moment for me, as I had been working on it for fourteen years. When the first books arrived, we opened a bottle of champagne in the office! In October of 2012 my meteorite exhibition, They Came from Outer Space, opened at Challenger Space Center Arizona http://www.theycamefromouterspace.com and the opportunity to design and curate a significant museum display was extremely rewarding for me. Steve was a big help with that project too, as he loaned us some of his remarkable meteorite finds. My latest project is working with Deep Space Industries, a private sector space exploration company that is building a fleet of robotic ships. They will be used to mine asteroids and return samples to earth. And I just love getting out and meeting the fans, and talking about our work with meteorites at gem shows and astronomy conventions. AW: I understand you are filming can we have a sneaky peak about the project?
www.astronomy-wise.com
13
GEOFF: I am currently working with Vivid Light Pictures, a New Mexicobased production company on the feature film Unfinished Business http:// www.vividlightpictures.com/ unfinished-biz.html The writer/director is Suzee Corbell and she's had a long and exciting career in film. I am a producer on the film and also playing the role of Dr. Josh Byrnes, a paranormal scientist with expertise in ghost hunting. Unfinished Business is a genre bending thriller that includes elements of film noir, paranormal, romance, action, and steampunk. Unfinished Business is now in preproduction and we expect to begin filming in February, 2013. AW: Can you tell me about your books?
GEOFF: I have been working as a science writer since 1998. Most of my articles focus on meteorites, but I have also written extensively about paleontology, history, astronomy, adventure travel, and the arts. My first book, Meteorite Hunting: How to Find Treasure from Space, is the world's first and only hands-on guide to finding rocks from space. It won a 2012 IPPY Award as one of the best independently-published science books of the year. My second book, Rock Star: Adventures of a Meteorite Man is my autobiography, and it was published Jun 1, 2012. The book was fourteen years in the making and, again, much of it focuses on my life as a meteorite hunter, but there are also chapters about my childhood in an abusive British public school, and my years as a professional rock 'n' roll musician. For years, I have been
IMAGE: www.vividlightpictures.com “The Vivid Light Pictures Studio in New Mexico, Where some of the interiors for Unfinished Business will be Filmed�.
archiving my best adventure and expedition photos and, as a result, Rock Star includes over 130 exclusive images. Both titles can be ordered directly from the publisher http://meteoritehunters.tv or from Amazon http://www.amazon.com/ gp/shops/storefront/index.html? ie=UTF8&marketplaceID=ATVPDKIK X0DER&sellerID=A2PPO5PARD0OR9 Steve has photo credits in both books, as there were numerous times when we were way out in the wilds, somewhere, hunting, just the two of us. We'd make a find, or there would be a terrific vista and I say to Steve: "Hey, take a picture of me here!" AW: Ok i know you are both busy so last question, do you both get chance to go out with a telescope on view the wonders of the cosmos?
www.astronomy-wise.com
14
GEOFF: We both had the opportunity to look through some excellent telescopes at the Stellafane convention in Vermont, this past summer, and I was most amazed by the Lagoon Nebula. I inherited my late father's old refractor, and I also have a Celestron NexStar. The joys of living in southern Arizona include our very dark skies and about 350 days of sunshine per year. I know this will make some of your readers envious, but for good astronomical viewing here, it's a simple as carrying my telescopes out into the back garden.
The Australian Outback at sunset. An image form Rock Star: Adventures of a Meteorite Man By Geoff Notkin
A big thank you the Geoff and Steve for taking the time to answer our Questions, to our reader please check out the links in the article they are live and one click takes you their source. Well folks we have some goodies to give away. We have signed books from Geoff so go to page 16 for more details on how to win a singed book.
www.astronomy-wise.com
15
www.astronomy-wise.com
16
Competition time To enter the competition you must answer the question set We have 2 rock star and 2 Meteorite hunting books to give away. So there will be 4 winners each winning one book each. All books are signed by Geoff notkin From the interview answer the following question: What is the largest meteorite Steve has found? Terms & Conditions: Answers are to be email to davebood@gmail.com Subject Meteorite Competition Closing date is March 31st 2013. All correct entries will be put into an hat and drawn at one of the Astronomy Wise Public meetings. The winner will be notified by email. We will ask the winner for their delivery address details. Competition open to UK only. The competition is free to enter. Four winners will be drawn winning one book each.
www.astronomy-wise.com
17
www.astronomy-wise.com
18
THE GREAT WINTER TRIANGLE When I was 12 years old in the days long before PCs and laptops, and was starting to become serious about Astronomy, there was only one way to learn the night sky. I had to go outside armed with nothing more than my eyes and a book in order to find the constellations and identify the stars by name. I remember at that time learning a fascinating short poem probably written by another astronomer describing one of the wonders of the winter sky, “The Great Winter Triangle” which we can all see around now if the weather permits. The poem goes like this: “ Let Procyon join to Betelgeuse, and pass a line afar To reach the point where Sirius glows, the most conspicuous star; Then to the eye’s delighted view, a figure fine and vast, Its span is equilateral, triangular its cast.” The Great Winter Triangle is made up of three of the brightest winter stars and can be seen very clearly in the accompanying star chart generated using Stellarium Software. I have connected the three stars together so that you can see the triangular shape. The stars reach their highest point in the southern sky at around 9pm during the second half of February, and if you are far away from streetlights where there is no light pollution, you may notice that the faint light of the Milky Way passes through this beautiful Triangle of three bright stars. Each star belongs to a separate constellation, so the Great Winter Triangle itself is not a separate constellation at all but is, what astronomer’s term, an “Asterism”, an interesting configuration of stars. Another example of an asterism is “The Plough” (USA: “Big Dipper”) in the northern sky. The Plough is an asterism of seven stars within the much larger constellation of Ursa Major, the Great Bear. Returning to the Winter Triangle, Procyon belongs to the constellation Canis Minor, The Little Dog. It is a yellow star almost twice the diameter of our sun and lies some 11.6 light years away. Procyon is the second nearest bright star visible in northern skies. As you look at it, you might like to reflect that the light of Procyon falling in your eyes left the star over 11 years ago! Nearer still, is Sirius, the lowest and brightest of the triangle’s three stars. Sirius, the Dog star lies in the constellation Canis Major, The Great Dog. Sirius is a pure white star 8.7 light years distant, but because it shines through a denser layer of atmosphere due to its altitude, atmospheric refraction causes Sirius to twinkle with all the colours of the rainbow. Take a look at Sirius through binoculars and see the spectacular coloured light show it seems to put on just for you! The Triangle’s third star is Betelgeuse, a red giant in the constellation of Orion, the Hunter. Betelgeuse is so big that if it were placed where our sun is, all four inner planets, including Earth and Mars would lie beneath its surface! Look quickly back and fourth between Sirius and Betelgeuse, and you will see the fiery light of the latter quite distinctly. John Harper F.R.A.S. President and Founder, Scarborough and Ryedale Astronomical Society (1976)
www.astronomy-wise.com
19
www.astronomy-wise.com
20
Part 2 Deep Space Imaging with a DSLR I often get asked how I take pictures of galaxies and nebula so here’s a brief guide showing how I do it. Firstly let me let me explain a few things. Because of the earth’s rotation the sky is constantly changing and although the stars may look almost stationary when using a telescope they actually move relatively fast. When you consider to take a deep space image we will be using exposures of up to 5 minutes the stars will have moved a considerable distance in the field of view. To combat this we use a mount that tracks the stars and attempts to keep them motionless for long exposures. As good as modern mounts are they still have errors and tend to start to drift after a minute or two. This isn’t a problem and we can just stay within our mounts limit but if we wish to exceed this limit a guide scope is used. This is second telescope, mounted piggy back style on the main scope or side by side, who’s role is to guide the mount and keep the stars static. To achieve this we attach a camera to the rear of the guide scope and aim it at a star near to our target. Guide scopes can be mounted via guide scope rings or a dedicated bracket such as the one offered by Skywatcher. I use the Skywatcher one because it allows me to adjust the direction that the guide scope is pointing in very easily. A simple turn of a thumb wheel is all it takes. You can buy standalone guide camera’s such as the one shown in the picture, a Synguider, or use one of many camera’s offered by QHY, TIS, Atik etc. Using one of these requires the camera to be connected to the laptop and then the laptop connected to the mount. Software such as PHD is then used to convert what the camera sees to movements the mount has to make. I use a Synguider as it connects direct to my mount eliminating the need to connect it to the laptop and use addition software. Once I lock the synguider onto a star I simply tell it to guide and it communicates with the mount informing it in which way to move to keep the star I locked onto completely stationary. Another method would be to use the finder as the guide scope and attach a camera to that. I’m unsure how effective this method is as the finder obviously has a much shorter focal length than the imaging scope and therefor the stars would move in the imaging scope before the movement was detected and corrected via the finder. Some people use off axis guiders. These work by being placed within the optical path. It comprises of a small mirror that redirects some of the captured light to a second guide camera. The benefits are that no guide scope is required resulting in a reduced payload on the mount
www.astronomy-wise.com
21
So what do you need? Well first off we need a driven mount that will track the stars. Next we will need a telescope. Any design of scope will work but the faster the scope the better. I use a refractor and a Newtonian. What you have to consider is the longer the focal length of the telescope the smaller the field of view. This has the added problem that it shows up any errors in tracking/guiding more. A good starter scope which is relatively fast with a nice 600mm focal length is the Skywatcher Evostar ED80. It is a Apo refractor which means it is almost completely free from achromatic abbreviation. Next up you’re going to need a camera. I use a Canon 500D DSLR which connects to the telescope via a T ring. There is lots of info on the web comparing DSLR camera’s that go into noise levels at various ISO settings at various exposure lengths. It’s all a bit complicated for someone just starting out in this hobby so I’m not going to go into it. Most of the newish models of camera’s available are pretty good with low noise levels. Remember in part 1 I touched on live view, well the same applies here, it’s great to be able to focus live on the laptop screen using the Brathinov mask also mentioned in part 1. To control the camera I use a program called Backyard EOS. This almost completely automates the capturing process. You tell the software how many pictures you want to take at what exposure level and leave it to run. The image on the right is a 4 minute exposure on M42 The Orion Nebula using a 2” Skywatcher light pollution filter. As you can see the filter gives the image a purplish hue but this can be removed during processing. So you have decided on the best exposure time for the circumstances. If you’re using Backyard EOS just input the amount of exposures to take and sit back. If you’re going to do it manually, which I did at the start, you will have to sit with the laptop/ camera and manually start and stop each exposure with the DSLR in bulb mode. You want to capture as many exposures as possible. The more we capture the more stretching during processing we can do and the less noise will be in the final image. Once you have completed taking your images, what we call ‘Lights’ we want to take a series of Darks. To take these you just put the scope end cap on and take a series of images with the same settings as the lights. Don’t change anything, keep the same exposure length as your lights. I usually take between 10 and 20 Darks. The purpose of these is to remove any hot pixels or amp glow from the final image. Next you need to take a series of flat frames. Again I take between 10 and 20. You can take these by opening a blank notepad document on the laptop and holding the www.astronomy-wise.com
22
screen against the scope. Another method is to take them at dawn whilst draping a white t shirt over the scope to diffuse the light and give an nice even illuminated field. I use the laptop method as I can take them just before I pack away. You need to keep the camera position and focus exactly the same as it was for the lights. This time let the camera decide on what exposure to use (AV mode). What a flat does is highlights the vignetting or uneven field illumination, In other words how the brightness varies from the centre to the edges, along with showing and dust and smudges present. Some people also take Bias shots but I don’t bother as I have yet to see any advantage. Right that’s it, you’ve imaged your target. Now download a free program called Deep Sky Stacker. Once you have this installed and running drag and drop your images in telling the software if the picture is a light, dark or flat. Then hit the Batch Stacking button and let it do its magic. The software will align and stack all your images before removing the data from the dark and flats. What you should be left with a combined image of all your lights. There is some very good tutorials about on the use of Deep Sky Stacker so I suggest you take the time to read one of them to familiarise yourself with the software. Put simply after stacking you align the Red, Green and blue channels in the histogram, up the saturation slightly and adjust the midtone luminance before saving and opening the image in your chosen photo editing software.
The image on the left is the result after stacking and processing 60 of the 4 minute exposures shown above.
I hope this brief guide has been of some use. Below are a few of my images with the settings and scope I used to capture them. All mages were captured using my Canon 500D DSLR. They should give you some idea what can be accomplished in a given time and particular scope. With some of the images I used a focal reducer. This reduces the focal length of the scope resulting in a wider field of view and a faster F number.
www.astronomy-wise.com
23
Left : Here is M31 The Great Andromeda Galaxy. To capture this I used a Skywatcher ED100 refractor with a Skywatcher 0.85 Focal Reducer. It’s the result of 60 exposures varying in length from 90 to 240 seconds giving a total exposure of 120 minutes. ISO set to 800
Right: : M42 The Orion Nebula Captured using a Skywatcher 250PDS Newtonian. Total exposure time is 90 minutes at ISO 800
Left: M45 Pleiades (Seven Sisters) captured using a Skywatcher 250PDS. Total exposure is 60 minutes consisting of 40 x 90 second exposures.
Right : NGC 7635 The Bubble Nebula. A cropped view captured using a Skywatcher 250 PDS. 80 x 90 Second exposures giving a total of 120 minutes. ISO 800
www.astronomy-wise.com
24 : M27
The Dumbbell Nebula. A cropped version captured using a Skywatcher ED100. 60 x 120 second exposures giving a total of 120 minutes at ISO800
M13 Globular Cluster. Cropped. Captured using a Skywatcher ED100. 30 x 120 second exposures totalling 60 minutes at ISO 800
Right: NGC 891 Edge on Spiral Galaxy. Cropped. Captured using a Skywatcher 250 PDS. 40 x 90 seconds totalling 60 minutes. ISO 800.
Images & Words Mike Greenham
www.astronomy-wise.com
25
www.astronomy-wise.com
26
Capturing the full disc of the Sun. Andy Devey This month I thought that I should cover how to capture the Sun’s full disc. The Sun is a very large target and beyond the size of most CCD chips in the video cameras that are now available to the amateur astronomer. Some of my friends use the larger chips in their SLR’s to capture the full disc through a telescope but these cameras have colour CCD chips and this will wash out much of the detail that is available to the monochrome CCD chip. The options available to today’s amateur solar astronomer are dependent on the personal goals that individuals set in this field. Some of my friends have opted for large frame CCD cameras such as the new DMK51 combined with a focal reducer such as a 0.5x Barlow, this will allow the user to shoot full frame video of the full solar disc. With this option every part of the Sun is shot at exactly the same time a real must with such a dynamic target in the field of view. Further the processing required to achieve the complete photo is restricted to just a few minutes. One friend uses this system to produce time-lapse full disc animations, these will show solar flares in the context of full disc and they are also very useful to capture associated shock waves [Moreton waves]. The images captured by the GONG network telescopes also capture full disc images, each image is a composite of two exposures one for the disc and another for the prominences. This is the easiest way to get full disc images but it does not deliver high-resolution full disc images. If your goal is to achieve medium resolution full disc images then you will need to take shots of the separate parts of the Sun and then merge them together in a suitable program such as Photoshop to create the full disc. Most imagers that I know will merge 4 or 9 panels to create the full disc. When tackling such a work it is essential to work fast as your target is moving [through plasma flow] and with a long delay the features will not match up across the different panels. If you have never tackled a mosaic I would recommend that you initially experiment on a static target that is about the same apparent size as the Sun, I am suggesting the Moon! If like me your goal is to achieve a very high resolution full disc, then longer focal lengths are necessary and this reduces the field of view so far more images are required to produce a full disc. The time element to process these larger images is significantly longer as I have recently found out. Making a mosaic Download the latest image from the active GONG site as this will help you rotate your camera to get the correct solar orientation before starting on your imaging run. www.astronomy-wise.com
27
To produce a successful mosaic it is vital to make sure that as the telescope is traversed across the face of the Sun and carefully ensure that the whole disc is covered with the photos taken. If an area is missed this is like trying completing a jigsaw only to find a piece missing! When I am making a mosaic I ensure that I have plenty of overlap with successive photos on all sides of the images. I normally start at the left side of the top of the Sun and traverse right while shooting 500 frame video sets and then move down working to the left and so on. The next stage is to process all the images to the same standard, this is fairly easy if the seeing is consistent and there are no thin cloud present but more difficult if not. I use Photoshop CS5 to construct my mosaics and I presently have no experience of other programs but there are many that are suitable. I start by opening a new document and initially select the International paper option [a large size sheet]. I then default the background colour to black using two brightness/contrast background masks and then I click on “layer” and “flatten image”. I import the first photo and set it in position, I then select and import the second photo and use the “move tool” and make it 50% transparent in “layer” this allows for fine positioning of one photo over the other [zoom in a few times to check for exact alignment]. Turn the layer back to 100% [fully on] and then select the eraser tool to merge the two together and remove any hard edges that show a clear indication that they are separate photos. Some of my friends use this process to build ¼ of the image as separate pieces and then at a later stage put the four quarters together to achieve full disc. Once the full disc is fitted together it may still look patchy with areas of dark and lighter tones. This can be smoothed out by selecting the eraser tool again at a low percentage say 2% and gently work on the darker patches to blend them lighter so that the image acquires a more even appearance. The colour layer can then be added after this stage. When I add the colour to my photos and movies I always use the colour balance mask with three separate layers for shadows, mid tones and highlight colours. I try to recreate an impression of the colours that I see in the eyepiece. The photographic equipment available and the image processing techniques are continuously changing and improving as technology advances. I personally am not expert in computing or advanced image processing techniques but I am always experimenting, willing to learn and also share my experiences and mistakes. Mistakes are a very valuable part of the learning process so just analyse what went wrong and then find the solution. The internet and particularly solar observing forums are an invaluable link to tap into the experiences of lots of expert amateur solar images and everyone is welcome to join in. I would recommend joining SolarChat and the solar section of the Cloudy nights forum. One expert solar imager Ken Crawford has posted an absolutely brilliant tutorial on solar image processing in Photoshop CS5 here is the link. I would recommend you www.astronomy-wise.com
28
work through this tutorial a great way to get your desired result without reinventing the wheel. Have fun with our Sun Andy Devey
Photo 1: Here is my first attempt at a high resolution solar mosaic; it comprises 40 separate photos taken at 1.6m focal length. At this stage I have merged the photos but not balanced the tones to make it look like a single image..
Photo 2 my first ever large scale mosaic attempt: a photo of the Moon in Memory of Neil Armstrong
Photo 3: Here is my first attempt at a large scale high resolution solar mosaic achieved with only very basic skill level in Photoshop CS5 usage. There is 20 hours work in this image and I shall revisit it from time to time in the future as my skill levels increase.
www.astronomy-wise.com
29
Photo 2
www.astronomy-wise.com
30
Photo 3
www.astronomy-wise.com
31
www.astronomy-wise.com
32
www.astronomy-wise.com
33
www.astronomy-wise.com
34
How do stars shine? What makes a star shine? It’s a question, more often asked of the Sun over millennia, but it applies to stars as well. It is only relatively recently we’ve had an answer to that. We should probably discount ideas based around various gods and chariots having nothing much better to do all day than ride across the sky, and presumably spend all night preparing to do it all again tomorrow. If you were a god, would this really be the limit of your ambition? Anyway, the first reasonable ideas centred around a large structure of burning coal. It’s a reasonable idea, and makes some sort of sense. Take what you know and make it bigger. However come the scientific age, and a good understanding of thermodynamics, it was soon found to be untenable. The Sun weighs in at about 330,000 times
the weight of the Earth, but even if it were all coal, and presumably sitting in some sort of oxygen rich environment, it would only provide around 5,000 years worth of burning. It might stretch to a few thousand more, or perhaps less - we can’t really do the experiment - but regardless, it is not going to keep us warm very long, at least historically speaking, never mind geologically speaking.
Another idea was dropping stuff onto the Sun. As things fall onto the Sun, they speed up and hit it with quite a whack. This gives off heat, and if you had enough stuff its a very efficient way to produce power. It powers the brightest objects known in the universe, objects that outshine entire galaxies, but it does require a lot of stuff to be consumed in the process. Lord Kelvin did a lot of these calculations in the mid 1800’s, saying he couldn’t see any way the Sun could shine for more than about 100 million years, unless there were some unknown mechanism at work. Come the twentieth century, and the era of radioactivity and nuclear physics, bringing with it the famous equation E=mc2, and suddenly new possibilities opened up for sources of power. Einstein’s famous equation means we can convert mass into energy, and c, being the speed of light, and a very big number, then squared, means a small amount of mass can make a lot of energy. It was known through spectroscopy that the Sun was made mostly of hydrogen and helium, so it was a good bet that whatever it was doing involved those elements in some way. Now if you weigh an atom of Helium, it is about four times heavier than an atom of Hydrogen. This is not surprising as everyday Helium is made up of 4 particles in it’s nucleus (two protons, two neutrons), and Hydrogen just one (a proton). However if you weigh it very very carefully, you find that 4 times the mass of Hydrogen, is a little bit more than a single Helium. That bit of missing mass would add up to quite a bit of energy, and if a lot of H’s are coming together to make He,
www.astronomy-wise.com
35
we have a plausible source of energy, nuclear fusion. Problem solved? Well not quite. There are a few awkward issues. First a Hydrogen atom consists of a single nuclear particle, a proton. A Helium nucleus is two protons and two neutrons. So you can’t just add 4 H’s together to make a He, somehow you’ve got to either borrow or make neutrons. There is also the tricky issue of getting two or more protons to stick together. You see protons have a positive charge, and like charges repel. So as you bring them closer together, there is repulsion between them. It gets stronger as they get closer too. It’s like pushing two magnets together; they try to avoid each other. Even if you could squash them together, there is no such thing as an element with two protons on its own. It would be called Helium-2 or 2He, but if it does ever exist, it falls apart back into two protons almost instantaneously. When two nuclear particles get very very close a new force can get to work, called the strong nuclear force. This can hold things together despite the electric force trying to push them apart. In this case though, it is just not strong enough to hold them, without some additional help, so it falls apart back into two protons. However, there is another force that can be useful. The weak nuclear force. As its name implies, it is weaker than the strong nuclear force, and indeed weaker too than the electromagnetic force. In truth its not much of a force either, but it does have a useful role. It is the agent of change, and in this case it can change a proton into a neutron, and should we get in the lucky position of getting two protons very close, and the weak force jumping in just at the
right point, we will end up with the change happening and a proton and a neutron stuck together. This is a very rare event, but luckily we have numbers on our side. It might take a billion years for this to happen to a given proton, but when you have billions upon billions of protons milling around in close proximity in the Sun, it will happen quite often. This slowness is actually a good thing, otherwise the Sun would go off literally like an H-bomb! To get two particles really close, they still need to overcome the repulsion,
and you can do this by throwing them at each other fast enough (this works with magnets too - but can get messy). How do you make protons move faster? Well one way is to heat them up. This is one reason the Sun needs to be hot, otherwise the particles would never even get close. In fact, the Sun is not “hot enough” to make this happen. If you do the calculations, and throw in the temperature of the Sun, they should never get close enough. Luckily the weird world of quantum mechanics they live in helps save the day, and sometimes they are allowed to break the rules a little
www.astronomy-wise.com
36
and “tunnel” into each other. Another key thing is to be all squashed together, so these fast moving tiny tiny particles might stand a chance of running into each other. So, this whole process makes a nucleus of deuterium, or heavy hydrogen as it is sometimes called. To balance the books, a positron is produced (an antielectron) so that we start with two units of charge and finish with two, and an anti-neutrino which helps balance energy and other quantities. The positron will find an electron in short order, and commit mutual suicide with it producing a gamma ray. After this step, its all downhill relatively speaking. It’s easy now
to bump another proton into the deuterium to make Helium-3 - which is stable, the extra neutron acts as a sort of nuclear glue. This probably only takes a few seconds, compared to the billion of so for the first step. Then the next step is two Helium-3’s to come together to make Helium-4 with the loss of two spare protons. This also happens relatively quickly, at around 10,000 years or so, peanuts in the life of a star. These last two steps also give off the most energy too.
www.astronomy-wise.com
37
At several stages along these steps, energy is released. It is released either as a particle of light - a photon in the gamma ray range, or as an antineutrino. The anti-neutrinos hardly ever interact with matter, and leave the Sun never to return. The photon of light meanwhile has a much harder journey. It bumps into protons and electrons and gets jostled around, but after several thousands of years, it makes it to the surface, and there it can escape to make the Sun shine. It is rather wearisome from it’s journey, so leaves not as a high intensity gamma ray the way it was born, but more commonly as a visible light ray, which is what we see (occasionally!) in the clear blue sky. This process is known formally as the proton-proton chain reaction 1 (or PP1 chain - there are other variants) and is what most small stars like our own use. Bigger stars have some more options which we might explore later.
How do we know all this? Well some of it by theory and calculation. Some of it by using neutrino telescopes which can look inside the Sun to some extent. Astroseismology (studying of sun-quakes) can also tell us some of the internal structure of the Sun. We’ve also made fusion reactions on the Earth, but usually in rather uncontrolled H-bombs, as controlled fusion has so far eluded us - although not for want of trying. Words: Julian Onions Twitter: @julianonions Astrophysics PhD student http://ou-know.blogspot.com/
Background Images: Andrew Devey Images: Wikipedia
www.astronomy-wise.com
38
ASTRONOMY Recent Discoveries & Developments
From the Reviews: This book is packed with interesting new topics in easily readable chunks. No maths, just plenty of illustrations in glorious colour, sprinkled with explanations and anecdotes. An excellent read for kids and grown-ups alike, ideal for browsing on a journey. Can't wait for the next edition‌ ‌Margarita
Although the lifetimes of stars and galaxies are played out over hundreds and thousands of millennia, the field of Astronomy itself is fast paced, with hardly a week going by without a new discovery or development hitting the headlines. This book delves into the most significant, ground breaking, headline making stories that have come out of Astronomy throughout 2011-12 and presents them in an easy to read, easy to understand format. The Perfect Introduction The Perfect Catch-up Available from Amazon in Kindle and Paperback Formats
For more information go to www.paulrumsby.com Facebook page: www.facebook.com/AstronomyRecentDiscoveriesAndDevelopments Follow the Author on Twitter @PMRumsby
www.astronomy-wise.com
39
Paul Halperns new book ‘Edge of the Universe’ A voyage to the cosmic horizon and beyond. The universe is a vast and complex place. It is full of mystery and wonder. We can peer out into the galaxy from our back gardens with small telescopes and see the stars and planets. However have you ever thought when gazing up how did this magnificent spectacle begin? How big is the universe? Is there more than one Universe?
Like you I have asked myself these and many more questions. Dr Paul Halpern who is an American Professor of Physics and a well publisher author may have the answers I am looking for. I downloaded the book onto my Galaxy Pad, using the Kindle app from amazon. Firstly the book is well laid out and easy to follow. It is not over complex and the beginner to Astronomy and those with an interest of the universe will quickly be absorbed into the pages. We soon learn that the universe is full of dark energy and dark matter. There are ideas on multi-universe and unseen dimensions. Download this book, buy this book in traditional form, which ever you choose get yourself comfortable and begin your journey to the cosmos. Astronomy Wise Rating 5/5
http://edgeofuniverse.com/
www.astronomy-wise.com
40
What Is Lurking Around The Plough? Some of you may have had a new Telescope for Christmas. Some may have a set of binoculars sitting in a draw which need a dusting off, or you may just wonder in awe at the delights of a clear night sky. It is easy to become overwhelmed with the millions of stars overhead, you may find it difficult to find an object in the sky. So to give you your bearings starting this month we are
going to have a look at constellations to get your bearings. However to make it easier we are going to take part of a constellation which is easy to identify and find. This is called an ‘asterism’. This means a small formation of stars which is recognisable, but is part of a larger constellation. The image below left shows the constellation Ursa Major or the Great Bear.
The Plough which is part of Ursa Majo is part of the night sky which most people find easy to find and pick out.
Finding the plough helps you find your bearings and you coordinates. The plough shape is quite distinctive in the sky and once found you can find North or the pole star Polaris. Ursa Major is a constellation which is in the night sky all year round. It appears to rotate around the Pole Star Polaris. Generally speaking the Plough is in a northerly direction. At this stage will imagine you are standing in a circle and you are standing in the centre. We can divide the circle into two halves, one we will call North and the other South.
www.astronomy-wise.com
or
.
41
The image to the left is an illustration, be it a simple one of finding north. Finding North and the North Star (Polar Star, Polaris) is how we polar align our telescopes.
This is really a brief and simple way of finding North and from here you can find other objects in the night sky. However these days many of you have smartphones, tablets, laptops etc. So downloading software such a Stellarium will help you navigate around the sky. ( http://www.stellarium.org/ ) The image to the right is an image taken using the Stellarium software. If you have a telescope or binoculars then there are some interesting objects to find and look at. The Plough is in my opinion an area of the sky which many overlook, however with a
little patients you too can view the wonders of this region of the sky. What to See! Here are some objects Planetary Nebula: M97 Owl nebula Galaxies: M51 (Whirlpool), M81,M82,M101,M108,M109 Double Star M40 Meteor Showers: Alpha Ursa Majorides, Ursiden, Leonider—Ursiden Multiple Stars: Mizor and Alcor
www.astronomy-wise.com
42
www.astronomy-wise.com
43
www.astronomy-wise.com
44
www.astronomy-wise.com
45
http://awesomeastronomy.com
www.astronomy-wise.com
46
Image Source: http:// www.ashbydelazouchmuseum.or g.uk/Tudors.html
www.astronomy-wise.com
47
www.astronomy-wise.com
48
Polar Aligning an Equatorial Mount The following procedure shows the polar alignment of an NEQ6 mount. This procedure can be adapted to most equatorial mounts. Step 1 : Place the Tripod in position so that the locating lug seen in this picture is facing roughly North. If you are using your telescope in the same place every time, ie a patio, it’s a good idea to mark the patio in some way so you can quickly put it back in the same position each time.
Step 2 : Level the tripod in all directions. I use a small level as this is much more accurate than the bubble levels built into mounts. Once this is done place the mount head on the tripod and tighten the bolt underneath Step 3 : Roughly set your altitude using the altitude bolts. You can find this info using your phone/ Google maps etc. I use a free app for the iPhone called Scope Help that has a few useful features .
The following steps 4, 5 and 6 only need doing the first time you set up the mount. Step 4 : Now loosen off the RA clutch and rotate the mount though 90 degrees. Place the level on the counter weight shaft and get it perfectly level before locking the clutch. Adjust the RA clock by loosening the small screws and rotating the clock ring until the arrow is pointing to 6 o’clock and lock the ring in place. Now loosen the RA clutch again and rotate in RA so that the clock www.astronomy-wise.com
49
shows 12 o’clock. The counter weight shaft should be now facing down. Take a black permanent marker and transfer a mark onto the mount as shown in the picture on the left. This has now marked the home position in the RA. When your black mark is in line with the arrow your mount is vertical. We need to do this because in further step we will be moving the RA clock. Step 5: With the RA still at 12 o’clock we will now set the declination clock. Loosen the Dec clutch and rotate until you can place the level as shown. Get this perfectly level and lock the Clutch. Now adjust the Declination clock as we did above setting it to 90 degrees. There is no need to mark anything as this clock has no need to be moved again. Now if you rotate the declination so that the clock reads 0 you mount will be exactly in its home position. Step 6: Now have a look into the polar scope. You will see something very similar to the image on the right. You can see Polaris is clearly marked as a small circle located on a large circle. Polaris isn’t actually stationary in the sky. It follows the path of the circle in the image. Loosen the RA clutch and rotate the mount in RA until Polaris is at the 6 o’clock position as shown in the image. Lock the clutch and now go back to the RA clock and set it to 0. This clock is now set and should be tightened as we won’t be moving it again. Step 7: Move the mount back to its Home position and put on your counter weights and scope and make sure everything is nicely balanced. Do this by firstly loosening the RA clutch and rotating the mount in RA. It should stay in any position you put it in. If it isn’t balanced it will swing so that either the weights go down or the scope does. Adjust the weights to obtain perfect balance. Next lock the RA in the position in the picture and then loosen the declination clutch. Now balance the scope by moving the dovetail within the mount or by sliding the telescope within the tube rings. Step 8: Ok now we are ready to turn on the mount and align with Polaris. If you haven’t got the Synscan handset then skip this step and obtain Polaris’s
www.astronomy-wise.com
50
position using your chosen method. Once you turn on your mount the handset will greet you with the version of software it is running before asking you to enter your location, time zone, date, time and daylight saving. Daylight Saving is British summer time so answer yes in the summer when the clocks have been moved forward.
Once we have entered all the above we will be faced with this screen. It tells us the last time Polaris transited (passed through the 6 o’clock position in our polar scope). What we do is loosen the RA clutch and rotate the mount in RA so that the RA clock shows the time shown at the top of this screen (00:24 ie 24 minutes past midnight). Lock the RA clutch and now look through the polar scope. By using only the altitude and azimuth bolts move the mount so Polaris is dead centre in its little circle. Depending on the Polaris time the small circle will be in different positions so don’t worry if it doesn’t look like my illustration. That’s it. Your mount is now Polar aligned and should track the night sky with a good degree of accuracy. After you have exited after this screen the handset will ask you if you want to begin alignment. If you answer yes it will give you the option of using 1, 2 or 3 stars. If I am imaging I normally only align on 1 star, choosing one that is near my target. If I’m just going to visually browse the sky hoping from one target to the next then I complete a 3 star alignment. I find that this then brings most objects nicely into the field of view when using the goto feature. Words & Images Mike Greenham
www.astronomy-wise.com
51
If you’ve just got an equatorial mount, this is a super quick guide to getting yourself polar aligned. It’s not as accurate as the full alignment (a full alignment guide is coming soon), but it will be more than good enough for visual observing and even medium exposure astrophotography. Steps 1-5 cover the initial set up, while steps 6-9 take you through aligning. 1) Make sure your tripod is level using the bubble level (if your mount has one) or use a spirit level on the tripod before attaching your mount. 2) Set your mount on its tripod, facing as close to north as you can (use a compass if you have one), add the counter weights then the telescope. 3) Rotate the Right Ascension (RA) axis to this position and check that the scope remains horizontal when you leave the RA clutch unlocked. Hold the scope while you try this! If the RA axis moves, adjust the counterweight until it - and the scope - are balanced. 4) Keeping the scope in this position, unlock the Dec clutch and check the scope remains horizontal. Again, hold the scope while you try this! If the scope starts to rotate, its position in its saddle will need adjusting until balanced. 5) Return both axis to the home/park position (pointing towards Polaris) and lock the clutches. 6) Find the latitude of your location (Google, GPS or an iPhone app can do this for you - Stockholm is 59º, London 51º, Vancouver is 49º, New York is 40º, Athens is 38º), and adjust the altitude adjustment screws until the arrow on your latitude level points to this number.
www.astronomy-wise.com
52
7) With the azimuth adjustment screws loosened, look through the polar scope and turn the mount until you can see the pole star – it will be far brighter than any other (see image right).
polar scope matches the software’s position.
8) As the pole star is not quite aligned with the North Celestial Pole, use some free software that gives you its current position (such as Polar Finderscope or Polar Finder). Rotate your RA axis until the view through your
9) Use the altitude and azimuth adjustment screws to move Polaris into the small circle on the edge of the larger circle.
www.astronomy-wise.com
53
You’re polar aligned! Return to the home/park position to begin star hopping or set your goto controller.
http://www.activeastronomy.org
www.astronomy-wise.com
54
The Night Sky.. By John Harper F.R.A.S As the month starts, the Sun lies within the constellation of Capricornus, the Sea Goat until it crosses the border with Aquarius on the 16th at around 04h, where it remains until the month’s end.
The Moon The moon’s perigee (nearest to the earth) occurs at 12h09 on the 7th, and apogee (furthest from the earth) around 08h30 on the 19th. Look out for ‘Earthshine’ illuminating the dark hemisphere of the waxing crescent moon from the 11th to the 16th, and the waning crescent on the 4th to 8th.
Last Quarter moon is on Feb 3rd at 13h57, in western Libra, 4° below Saturn
New Moon is on the 10th, at 07h21 on the Capricorn/ Aquarius border and passes 4° north of the sun.
First Quarter, 17th, at 20h31 in Taurus, 8° to the west of Jupiter
Full Moon is on the 25th at 20h27 in the constellation of Sextans the sextant, 10° below Regulus the brightest star in Leo.
www.astronomy-wise.com
55
The Planets The first of two favourable evening apparitions of Mercury takes place this month, during which the planet reaches its greatest elongation (18°) east of the sun, during the evening of the 16th. Look for Mercury low in the WSW sky soon after sunset, when binoculars will help you spot its bright scintillating starlike appearance. If you scan the area of the sky just mentioned on the 8th, just before 18h, you may be able to see a close conjunction between Mercury and Mars, when the two are separated by a quarter of a degree (half a moon width). However, the two objects are low in the sky, some 5° above the horizon at this time. On the 11th there is a challenge of spotting the very thin waxing crescent moon and Mercury and the very much fainter Mars. Mercury is 4° to the lower left of the moon; whilst Mars is 2° below Mercury. For observing Mars, binoculars are necessary as the planet is now far from the earth and on the other side of its orbit. The time to attempt this challenge is around 18h in a clear sky, as the three objects are within 10° of the WSW horizon.
Venus is still a morning object, rising in the SE, just half an jour before the sun at the very beginning of the month. The extremely thin, waning crescent moon lies 4° above Venus on the 9th and you may be able to spot the two as the pair is rising at around 07h30. Venus is very close to the horizon, but it will be spotted easily in binoculars, as will the moon. By the middle of the month, Venus is lost as it moves behind the sun towards its superior conjunction with the latter at the end of next month.
www.astronomy-wise.com
56
Mars is very difficult to spot in the evening twilight, when during the month it sets approximately one hour after the sun. Worthwhile occasions for trying to locate the red planet have already been described above. During the month Mars is comparable in magnitude to its ‘rival’, Antares in the constellation of Scorpius. (Antares means ‘rival’ of Mars, whose Greek name was Ares)
Jupiter is visible high in the south during the month as evening twilight fades; indeed it is the first star-like object to appear in the sky after sunset. The giant planet is moving slowly eastwards in Taurus somewhat midway between the constellation’s brightest star Aldebaran and the glorious Pleiades open cluster. The first quarter moon may be seen approaching Jupiter on the 17th, forming a pretty triangle with Jupiter and the Pleiades. The following evening, the 18th, there is another interesting alignment, when the slightly gibbous waxing moon lies 3° to the lower left of Jupiter and 3° above Aldebaran. Don’t forget to look for the Galilean satellites and the craters on the moon at this time, through firmly fixed, well-focussed binoculars. As the month proceeds, Jupiter sets from between 04h at the beginning to 02h at the end. Saturn in the constellation of Libra, rises at 01h as February begins and at a few minutes past 23h as the month’s end. It is now becoming a beautiful sight with the northern surface of its ring system well presented to earth. It is a wonderful sight even in a small telescope. There is a conjunction between Saturn and the last quarter moon on he morning of he 3rd, when at 06h in a brightening sky, the ringed planet lies almost 5° above the moon with the terminator (the line separating the lunar day and night hemispheres) pointing towards the planet. The two objects are to be seen at an altitude of 20° in the south. Uranus is a faint object to be looked for in the evening skies of February before it sets at 22h at the beginning of the month, and 20h at the end. You will need a star chart and binoculars to identify this remote world, as its position is in an area of he sky devoid of any bright ‘marker’ stars other than Alpheratz and Algenib which point down to the planet’s faint greenish blue disc as seen through astronomical telescopes.
www.astronomy-wise.com
57
Neptune is in conjunction with the sun on the 21st and is lost in the glare of the latter during February.
Constellations visible in the south around midnight, mid-month, are as follows: Cancer, Leo, Hydra, with its brightest star Alphard (‘the solitary one’), and the faint constellation of Sextans the Sextant, to be found just below Leo’s brightest star Regulus. All times are GMT
1° is one finger width at arm’s length.
www.astronomy-wise.com
58
www.astronomy-wise.com
59
www.astronomy-wise.com
60
Welcome to Scope Review - Part 3
This is the last of three articles covering astronomical telescopes. In the December and January editions of Astronomy Wise we looked at beginner’s telescopes around the £150 mark and Intermediate instruments between £300 and £1,000. To conclude the series we will look at advanced scopes currently on the market costing in excess of £1000. This section of the market is dominated by the Catadioptric design. There are some superb Dobsonians like the Meade 16” LightBridge and a raft of large aperture Refractors available but in this area my money is on the Meade and Celestron Cats, instruments that offer a wealth of features and are at the forefront of new technology and development for the amateur. Let’s start with Celestron and their NexStar range. The series comes in 4”, 5”, 6” and 8” versions but only the 8” fits nicely into this section costing around £1,250. This 8” scope (right) is a good all round performer but not ideal for astrophotography as the mount takes a while to settle when touched. The computerised GOTO mount has 40,000 objects in its database and is easy to set up but lacks GPS, which comes as a plug in optional extra. For those wishing to immerse themselves in the world of astrophotography the more stable design of the C6 S-GT XLT (right) may be worth considering but at £1,400 you get 2” less aperture for the increase in cost.
www.astronomy-wise.com
61
Moving on to Meade’s offerings we have the tried and tested LX90’s, the 8” version (Left) comes in at around £1600 with its 10” Advanced Coma Free (ACF) sibling costing around £2400. Both are outstanding performers but require an equatorial wedge for long exposure astrophotography.
The LX200 range of scopes are the workhorses of many an amateur astronomer and society. The range includes 8”, 10”, 12”, 14” and a massive 16” instruments. Starting at around £2500 for the 8” and a whooping £16000 plus for 16” (far right), these are serious pieces of kit with serious price tags. Be warned, the 12” version and up will require 2 people to setup and are more at home permanently installed in a dome than in the back yard.
To conclude, if money really is no object or maybe just to dream awhile, we have the Meade Max2 20” (0.5m) personal observatory. This telescope has so many features it’s hard to list them all but at £35,000.00 one would expect quite a lot. Get’s have a look at the main ones:
www.astronomy-wise.com
62
20" (0.5m) Aperture Fast f/8 Advanced Coma-Free™ optics Electronic Front Focusing 13.625" gears 250 lb total payload Clutchless precision-loaded worm-drives Carbon Fibre/Kevlar Optics Tube Internal Cabling Local Network Control Remote Web Control Robotic German Equatorial Mount Improved counterweight and OTA support Dual imager integrated autoguider Ultra Precision Pointing Assisted Drift Alignment Meade's Ultra High Transmission Coatings (UHTC™), Electronic Front Focusing System Laser-Aligned Primary Mirror Diffraction Limited Optics Electronic Collimation Computer-Optimized Baffling, Cooling Fan Multi-port control panels Carbon Fiber/Kevlar Optical Tube, Built-In Anti-Dew Heater GPS Receiver Patented Level North Technology
I hope you have enjoyed this short three part overview of astronomical telescopes currently available on the market. We have seen that all budgets are catered for and some great deals can be found. The technology available to the amateur increases yearly and one can only wonder what will be on offer in five to ten years time. Clear Skies, Paul Rumsby
www.astronomy-wise.com
63
UNIVERSE PLAYS FOOTBALL by Pepe Gallardo It may seems that the title is bizarre but Universe is bizarre also. Obviously it is some of the jokes that astronomers and cosmologists plays since Universe is fun. What you can see in the image is an object which is 14,700 light years from the Earth toward the center of the Milky Way. It is the debris of an explosion, that is a supernova remnant. The final stage of a star could be its death in form of a violent explosion called a supernova. The glow of its debris is the supernova remnant. These remnants are called G350.1-0.3. After the explosion the remain is a neutron star and a glow. But, as you can see in the image, the supposed neutron star is far away from the center of X-ray emission which means that the star has got a violent kick to be displaced. It is as if the supernova played a cosmological football play. This region has more intriguing features such as its shape. Usually many remnants are spherical but this one is asymmetric. It could be due to the stellar debris expanding through the cloud of interstellar gas. It is believed that the explosion took place between 600 and 1,200 years ago, which means that is a new event similar to others ones such as the supernova in Crab Nebula or in SN 1006. This time these debris could not be viewed by an optical telescope since X-rays are colour in gold and infrared in cyan, purple and green. Credit: NASA/CXC/SAO/P.Slane, et al.
www.astronomy-wise.com
64
Saturn by Liam Tomos Edwards The ringed planet Saturn is the sixth planet away from the Sun. It is also the second largest planet in our solar system, after the fifth planet from the Sun, Jupiter. Saturn was named after the Roman god with the same name. Saturn is what’s known in astronomy as a ‘gas giant’. A gas giant is a large planet mostly made up of gas. It has a radius of about 9.45 Earth’s (diameter of about 120,536km). Saturn is primarily made out of hydrogen (96%) with a small percentage of helium (3%) and an even smaller percentage of various other trace compounds including methane, ammonia, ethane and hydrogen deuteride. This planet is made famous by the majestic and complex ring system it has around it. In this article we will delve into the mysterious and alien world that is the planet Saturn. Saturn is classified in astronomy as a ‘gas giant’ planet. This means it has an exterior primarily made of gas and it lacks a definite surface. Scientists believe it does however have a solid core made out of hydrogen being squashed into a metal by the immense pressures and temperature deep down in the bowels of the planet. Due to the rotation of the planet, it is shaped into an oblate spheroid – basically, it’s flattened at the poles and bulges outward in the middle. All the other gas giants are also oblate spheroids, but not to the same extent as Saturn. Saturn is also the only planet in the solar system that has a density lower than water (i.e. it is the only planet that, given a bathtub big enough, would float on water). Its average density is 0.69g/cm³. The largest planet in our solar system, Jupiter, is about 318 times the mass of the Earth whilst Saturn is only 95 times the mass of the Earth – even though Jupiter is only 20% larger than Saturn. But they’re still massive because together they hold 92% of the mass of all the planets in the solar system. Most of the planet is gas (hydrogen and helium with some trace compounds) but it has got a solid core. The pressures, temperatures and densities deep within Saturn cause gaseous hydrogen molecules to transition into solid metal. The core is about 9-22 times the mass of the Earth which means it’s about 25,000km in diameter. This solid core is surrounded by a thicker layer of liquid metallic hydrogen (basically a soup of metallic hydrogen whizzing around), followed by a liquid layer of ‘helium-saturated molecular hydrogen’ that gradually turns into a gaseous state the further away from the core you go. The outermost layer is the atmosphere which we can see, and it spans a further 1,000km. Although the average temperature of Saturn is about -178°C (-288°F), the temperature in its core is about 11,700°C! This is due to Saturn’s immense gravity compressing its core (this mechanism is called the Kelvin-Helmholtz Mechanism). Moving on now from Saturn’s core to the atmosphere itself. Saturn’s atmosphere is a wild and chaotic place with storms raging almost constantly. We don’t see most of these storms however because they happen lower down in the atmosphere, just out of sight. The outer atmosphere consists of 96.3% hydrogen and 3.25% helium. The quantity of elements heavier than helium is unknown but is estimated to be about 25 times the mass of the Earth – with most of that making up the core. The upper clouds are composed of ammonia crystals which give Saturn its distinctive cream coloured appearance, while the clouds lower down in the atmosphere consist of either ammonium hydrosulphide (NH4 SH) or water molecules. Saturn does have bands of clouds but they’re much fainter than Jupiter’s iconic bands. www.astronomy-wise.com
65
Saturn does have some pretty nasty weather – it has the second fastest winds in the entire solar system with wind speeds of about 500m/s (1800km/h). This planet also has fantastic cloud patterns such as the North Pole Hexagon situated about 78° north of the planet’s equator. Each side of this hexagon are about 13,800km long making them larger than the diameter of the Earth! The pattern’s origin is under much speculation but most astronomers believe it was caused by some wave pattern in the atmosphere. Another fantastic feature of Saturn is its great magnetosphere that is about 1/20th the strength of Jupiter’s, but it’s strong enough to deflect charged particles coming off the Sun and thus aurora can be seen around the planet’s poles. Saturn is, on average, about 1.4 billion kilometres (9AU) away from the Sun. It has an average orbital speed of 9.69km/s and completes one orbit of the Sun in 10,759 Earth days (29 ½ Earth years). The planet turns once around its axis in 10 hours, 32 minutes and 35 seconds as of September 2007. The most notable and, in my opinion, the most beautiful thing about Saturn is its wonderfully graceful system of rings. They extend from 6,630km to 120,700km above the planet and are, on average, 20m thick. 20m might be a lot here on Earth but compared to Saturn, it’s very, very thin! The rings are composed of mostly water ice (93%) and those pieces of water ice can vary from a few millimetres to 10’s of metres in size. But don’t be fooled, all the other gas giants have ring systems around their equators; they’re just much thinner and therefore much fainter than Saturn’s. Nobody knows exactly how the rings were formed but the main hypothesis is that the rings came from material in orbit around Saturn that had not coalesced into one of the Saturnian moons. This material either came from a very old moon of Saturn that crashed into another old moon and caused all the debris to fall into fine orbits around the planets equator, or the material was already there from the nebula our Sun and everything else in the solar system formed from. The last thing I’d like to talk about is Saturn’s intricate network of many moons that orbit the planet at various distances. Saturn has around 62 moons of different sizes ranging from the mighty Titan (5,152km in diameter) to Aegaeon (1/2km in diameter), although most of Saturn’s 62 moons are very small ‘moonlets’. Titan is a truly fascinating place for astronomers for many reasons. One, Titan accounts for 90% of the mass orbiting the planet so it’s pretty big for a moon. Two, the surface temperature of Titan is -179.5°C which is the temperature of liquid nitrogen – and if you have any interest in anything scientific, you’ll know that liquid nitrogen is pretty cold stuff! The surface of Titan is in fact so cold that it has lakes, rivers and perhaps small seas on it, but they’re not lakes of water like we have here on Earth, they are lakes of liquid methane. This also leads onto the third reason why Titan is a cool (pardon the pun) place to study. Third, Titan has rivers and lakes of liquid methane which means that, if methane can form there, so can lots of other hydrocarbons like ammonia which can ultimately lead to life. Another interesting moon of Saturn is Enceladus. Enceladus is only 505km in diameter, which is pretty small in astronomical terms, but underneath its surface there’s thought to be a liquid ocean with more water than there is on all the Earth’s oceans combined! In 2008 astronomer located plumes of water ice ejecting from the south pole of the moon at speeds of about 1,360mph (2,189km/h). The get the plumes travelling at that speed there needs to be a lot of liquid involved. It’s also thought that the ocean beneath Enceladus’ surface is salty due to the reason that, in the section of the rings where Enceladus lies, salt particles have been found
www.astronomy-wise.com
66
along with water ice particles. These could only have come from Enceladus due to the fact that the ringlet is constantly full of these particles which mean something is constantly pumping them into the system. So Enceladus is also a candidate for extraterrestrial life due to the chance of a liquid water ocean underneath its surface. In ancient times, Saturn was thought to be the last planet in our (then-unknown) solar system because telescopes hadn’t been invented and therefore Uranus and Neptune were too far away/too dim to be seen without the aid of optics. Then, in 1610, when Galileo Galilei pointed his primitive telescope at Saturn, he saw something he did not expect. Something either side of the planet that he just could not explain, although he gave it his best, his best theory was that the planet had ears! So Saturn’s rings eluded us until the Danish astronomer Christian Huygens used a larger telescope to see that they were in fact rings. Then, the next important discovery in the history of our observation of the rings of Saturn came from Giovanni Domenico Cassini in 1675 who discovered there was a gap separating the rings into two main sections. This was known as the Cassini Division in honour of the discoverer. The last major discovery came when astronomers discovered that the rings were in fact made up of smaller rings called ‘ringlets’. These ringlets where then categorized and given names. The 5 major components of the rings where
called the G, F, A, B and C rings. However, in reality, these five major ringlets are divided into thousands of even smaller ringlets. orange and ultraviolet frames obtained by Voyager 2 on August 17, 1981 from a distance of 8.9 million km (5.5 million miles). Credit: NASA
Astronomers have been fascinated by Saturn for thousands of years and that enthusiasm and dedication to know more about it has not faded over the past 10 or-so years. Both NASA and the ESA have sent many probes and satellites to orbit the planet (or to fly by it) to take pictures with increasingly better resolution. It started with Pioneer 11 which carried out its first flyby of Saturn in September 1979, when it passed 20,000km above the clouds. Pioneer 11 made some pretty important discoveries while it was operational – it discovered the thin F-ring and also measured the temperature of Titan. Then came the two Voyager spacecraft, Voyager 1 and Voyager 2, to try and discover even more about this mysterious world. In November 1980, Voyager 1 arrived at Saturn and sent back the first high-resolution images of Saturn, the rings and its moons. For the first time, geological features were seen on some of the moons, this was something that Pioneer 11 couldn’t achieve due to the poor resolution of its cameras. Due to the vast amount of things to see and record around Saturn, NASA astronomers were spoiled for choice! They also only had a limited amount of time to choose where to point the spacecraft’s cameras so they opted to try to take pictures of Titan. This would prove to be a mistake NASA would regret because in order to get the pictures of Titan, they had to adjust Voyager 1’s course and that meant www.astronomy-wise.com
67
taking it out of the plane of the solar system. However, NASA chose to continue with Titan and as the spacecraft approached the moon, it soon dawned on NASA that none of the cameras on board could penetrate the thick atmosphere of Titan and could therefore see no surface detail at all. Voyager 1 was now hurtling out of the plane of the solar system, never to return. Voyager 2 however was much more successful than its counter-spacecraft because almost a year later, in August 1981, Voyager 2 continued the study of the Saturnian system. Many more high definition images of the system were acquired which led to more discoveries such as the small Maxwell Gap (a gap in the C-ring) and the Keeler Gap (a 42km wide gap in the A-ring). Saturn’s gravity then helped push Voyager 2 towards its next celestial target, the planet Uranus in a process called a ‘slingshot manoeuvre’ which uses the gravity of a planet to give spacecraft/ space
This image has been generated with Celestia; 3D model by ElChristou
probes more kinetic energy (i.e. acceler- and perhaps even in our close cosmic ates it) and also bends the spacecraft’s neighbourhood. trajectory slightly. The final spacecraft is the CassiniHuygens spacecraft which was launched Image: NASA from Earth in October 1997 and is still in operation around the Saturnian system today. In July 2004, the probe entered an orbit around the planet and sent some of the first pictures of Saturn’s moon Phoebe a month before in June 2004. Cassini has captured some truly breathtaking photographs of the Saturnian system but one of its major achievements was landing a probe (called Huygens) on the moon Titan. That was the only landing of a human-made object on a celestial body outside the Earth-Moon system to date. So to conclude, Saturn is a mystical place filled with beauty, complexity and awe-inspiring examples of just how amazing the Universe is and personally, I believe Saturn should be explored much more for it houses a few of the most promising environments for extraterrestrial life in our Solar System www.astronomy-wise.com
68
www.astronomy-wise.com
69
www.astronomy-wise.com
70
www.astronomy-wise.com
71
www.astronomy-wise.com
72
www.astronomy-wise.com
73
www.astronomy-wise.com
74
www.astronomy-wise.com
75
www.astronomy-wise.com
76
www.astronomy-wise.com
77
www.astronomy-wise.com
78
www.astronomy-wise.com
79
www.astronomy-wise.com
80
And Now For Something Completely Different……… With the blues of January gone we thought we would do something different, something Calming. Our regular writer Zantippy Skiphop has put together some short poems about Jupiter's moons.
Haikus for Jupiter's Moons: the Conquests of Zeus Zantippy Skiphop
Io Many-Eyed has failed. I morph into fiery beings. Zeus can't find me here.
Io image credit: NASA/JPL/Voyager1 Europa He pulled me from land Guarding Father's still waters. There's life within me. Europa image credit: NASA/JPL/Ted Stryk Ganymede My iron cup Feeds the crowing cock. Hera is not pleased. Ganymede image credit: NASA/JPL from Galileo Spacecraft
www.astronomy-wise.com
81
Callisto Owl moon castaway. Nymph foot in icy waters. Still, I'm luminous. Callisto image credit: NASA/JPL/Caltech
http://zantippyskiphop.blogspot.co.uk
www.astronomy-wise.com
82
Astronomy Wise went out and about in January.
St Marks Brownies Scarborough invited AW members to continue helping them with their Stargazing badge. They had to observe and name some objects. Jason Ives and Neil Samples were kind enough to set up their telescopes for the troop to look through. Conditions were not good with Jupiter being the most visible. John Harper (FRAS) gave a little talk and asked the girls some questions. In line with stargazing Live we gave out the free stargazing live booklet. A big thanks to Alison Birley for asking us to come along.
www.astronomy-wise.com
83
Sawdon Village Hall– 11/1/2013 The first meeting of 2013 was upon us. Stargazing live had just been on the telly and this was our first event in line with the Stargazing Live event. It was our intention to give the public a chance to look through different telescopes and see the wonders of the cosmos above. However the British weather was against us and thick fog descended onto the event. In the hall tea and coffee was on sale, the team had set up the laptop for a talk and we decided to put telescopes around the room. This would give members of the public a chance to come and talk to the AW members about different telescopes and generally ask questions. Through the BBC print outs were provided and we had the Stargazing live booklets to give out. Despite the poor weather conditions the room was soon full. Jason and I firstly got up and introduced the event, and after prompting by Carl Dutton we finally introduced ourselves to the group. The BBC had provided a DVD which was an introduction to Stargazing Live events. The DVD was hosted by Prof. Brian Cox. This gave people the chance to see what the event is about and to look at some of the wonders in the night sky. John Harper (FRAS) gave a talk and this was to introduce people to the solar system and some of the things we may have seen if the skies had been clear. Refreshments were provided by Jacqueline Ives, Mr Ives’s better half. During the break AW members were on hand to answer any question and let people look and have a play with some of the scopes. The second half of the evening we had a closer look at the planets. A big thanks to all that came along and to the AW members who came along and helped out. Clear Skies……. Dave Bood
www.astronomy-wise.com
84
Android Free Apps It is back a pick of Astronomy & Space Android apps for your phone or tablet. As always tested on a Samsung Galaxy 10.1 tablet.
Messier Catalog is basically what is says. It is a list of Messier objects. This application is ideal when you are out viewing through a telescope, look at objects such as the Orion Nebula M42 and find out more information about it. The App. Also gives you an image of what you are seeing. Ideal learning tool for all Google User Rating 4.4/5 AW Rating 5
www.astronomy-wise.com
85
I think in recent years asteroid tracking has become more popular. NASA tracks and publishes details of asteroids, the news covers near earth asteroids so why not have a tracker as an application on your phone or tablet. AsteroidTracker is a science aggregation app that displays tracking information about Near Earth Objects from the NASA NEO program. (Google Play) App Link HERE Google Rating 4.4/5 AW Rating 4.6/5
www.astronomy-wise.com
86
ASTEROID WATCH FEBRUARY 2013
www.astronomy-wise.com
87
Near Earth objects is a new monthly feature. Each month we will give you a run down of objects zooming past earth. Date (Feb 2013)
Object Size (m)
Distance (Km)
1
9
16,291,441
1
158
8,018,560
2
680
28,543,678
2
470
21,961,280
3
45
12,012,881
3
255
28,139,760
4
151
21,796,718
4
58
10,606,640
4
110
4,697,440
5
1,295
22,305,360
7
58
8,826,400
8
195
11,085,400
12
31
11,085,360
12
109
11,504,240
12
3,400
22,110,880
13
205
24,220,240
13
62
1,421,200
14
21
14,062,399
15
2,100
18,894,482
www.astronomy-wise.com
88
Date (Feb 2013)
Object Size (m)
Distance (Km)
15
335
21,751,840
15
58
29,920
15
95
12,132,520
16
485
14,152,160
17
151
20,944,002
20
595
23,307,680
24
18
26,539,038
25
1,020
22,933,680
25
270
15,049,760
28
295
20,749,518
FEB 15TH 2012– ASTEROID 2012 DA14 CLASSIFICATION APOLLO SPK-ID 3599602 2012 DA14 will sweep close to the Earth, however it will not hit us. In terms of closeness It’ll pass within the moons distance from Earth – closer than the orbits of geosynchronous satellite . Time 19:26 UTC/GMT MAG less than 7 just fainter than naked eye viewing.
Image: Wikipedia Information: NASA Data: Android Application NEO Driod
www.astronomy-wise.com
89
www.astronomy-wise.com
90
www.astronomy-wise.com