The Southern Astronomer No.98 – November 2016
SOUTHERN ASTRONOMER THE
MONTHLY MAGAZINE OF WORTHING ASTRONOMERS & WORTHING SKYWATCHERS
© Andy Lee
Nova in Sagittarius
The Southern Astronomer No.98 – November 2016
WORTHING ASTRONOMERS No fees, no Committee; just enjoying the night sky together.
F
ormed in 2008 by a group of regular and practical observers, Worthing Astronomers is a free to join society now with a membership of about 450 persons, who have a common interest in Astronomy and its associated subjects – no internal politics, no fees, no committees, just astronomy!
The Southern Astronomer This Issue Astronomy This Month Observing : The Planets The Moon The Sun Meteors & Comets Workshop Report – October Meeting Looking Up: November Night Sky Monthly Sky Map
Our aim is simple – to bring astronomy to the public in general and to help and assist our membership in observing the night sky. With the aid of this newsletter, website, social media, regular star parties, workshops and public observing events we hope to encourage and share our interests in observing the sky with the public, our colleagues in our own group and with those of neighbouring astronomical societies.
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Cover Picture & Comment
We try and meet at least once a month (when weather conditions allow) to do some observing but we do hold every two months a Workshop evening when we get a chance to meet up, exchange ideas and tips and help each other to make the most of observing the sky above us. Occasionally a guest speaker will talk about an aspect of practical, hands on astronomical observing or photography.
The last part of October saw a brief flare up of a Nova in Sagittarius. It went up from a faint 11m to 8m before fading once more. Andy Lee captured the nova a few days after its discovery. The Full Moon this month occurs at perigee and we get to ‘see’ a larger than normal Full Moon in the sky, though I doubt if like me, anyone will be able to see the real size difference at all – the angular diameter of the Moon in the night sky can vary from 29’.3 to 34’.1 arc-minutes due to the slight ellipticity of its orbit around the Earth – a difference of 14%. We talk about the Moon-Illusion on page 5.
These Workshop evenings are held on the first Friday of every other month (February, April, June, August, October and, December) at Goring Methodist Church Hall, Bury Drive (off of Aldsworth Avenue), Worthing, BN12 4XB. The admission charge of £3 helps pay for the room and free refreshments and goes towards supporting our membership. Doors open at 7.00 pm with the meeting starting at 7.30.
Talking of sizes, you may notice that from this issue the text font size on some of the pages is now slightly different – many members print out pages and some of the print in previous issues was font size 7 – which is a little difficult to read in printed form, so the font size has been increased to 8 and is uniform across the pages. I hope this meets with everyone’s approval.
We can be found at: worthingastronomers.org.uk
There are several astronomical groups in the coastal area of Sussex - several WA members are also members of the Adur Astronomical Society, who meet every first Monday of the month for a lecture regarding an astronomical subject. Details for AAS can be found at Adur Astronomical Society
Amateur astronomy in the UK has seen a resurgence over the last sixteen years or so with telescopes and sundries at low prices that I have not seen in all my years of stargazing. That may now all end as UK sterling is affected by the so-called Brexit and the buying power of the £ is reduced. Instead of buying new perhaps we shall start enhancing the equipment we have or, shall we go back to the ‘old’ days when the only way to get a cheap yet large telescope was to build it yourself – grinding the main mirror and building the tube and mount? Time and the pound sterling will only tell.
CONTRIBUTIONS AND UNSUBSCRIBING Contributions – written articles (word processed in .txt, .doc or .odt format), photographs, letters, advertising copy to the editor for the December issue should be in by November 15 and sent to the editor at the contact address: editor@worthingastronomers.org.uk
Contact addresses: Joint coordinators - info@worthingastronomers.org.uk – general society details, Janet Halls or Brian Halls
If you no longer wish to subscribe to the group and cancel newsletters and other information, please send an email to: info@worthingastronomers.org.uk with 'Unsubscribe' in the subject line; we do not want our stuff to end up like spam littering your inbox.
treasurer@worthingastronomers.org.uk – donations contact Janet Halls
Volunteers are always welcome: if you want to find out more, call 01903 521205 or drop us a line at the e-mail address above.
website@worthingastronomers.org.uk – contact for website Perry Wilkins
If you like the newsletter or its content please feel free to distribute it to anyone you know who might be interested. Content is subject to copyright to the group and/or the individuals whose images or articles are used.
editor@worthingastronomers.org.uk – newsletter content detail Brian Halls
outreach@worthingastronomers.org.uk – events contact Steve Bassett, Mike Williams
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The Southern Astronomer No.98 – November 2016 DEEP SKY OBJECTS
ASTRONOMY
THIS MONTH
November 2016
All times are expressed as Universal Time (UTC – Co-ordinated Universal Time) and can be considered the same as GMT (Winter Time) Information given, unless otherwise stated is for the 15 th of the month at 21.30h.
SUBJECT TYPE
Constellation
MAG
RA (h m)
DEC (° ' )
M31
Galaxy
Andromeda
3.4
00 42.7
+41 16
M32
Galaxy
Andromeda
8.1
00 42.7
+40 52
M110
Galaxy
Andromeda
8.1
00 40.4
+41 41
NGC404 Galaxy
Andromeda
10.3
01 09.4
+35 43
NGC752 Open Cluster
Andromeda
5.7
01 57.7
+37 40
NGC680 Galaxy
Aries
11.9
01 49.8
+21 58
Lunar and other phenomena in the Quick View Diary are shown to the nearest hour.
NGC691 Galaxy
Aries
11.4
01 50.7
+21 46
NGC697 Galaxy
Aries
12
01 51.3
+22 21
Darkness is now with us for the evenings and early mornings giving us greater opportunity to explore the night sky.
NGC772 Galaxy
Aries
10.3
01 59.3
+19 00
Cr463
Open Cluster
Cassiopeia
5.7
01 48.4
+71 57
IC1747
Plan. Nebula
Cassiopeia
12
01 57.6
+63 19
NGC581 Open Cluster
Cassiopeia
7.4
01 33.4
+60 39
NGC129 Open Cluster
Cassiopeia
6.5
00 30.0
+60 13
NGC133 Open Cluster
Cassiopeia
9.4
00 31.3
+63 21
NGC146 Open Cluster
Cassiopeia
9.1
00 32.9
+63 19
NGC185 Galaxy
Cassiopeia
9.2
00 39.0
+48 20
NGC225 Opn Cluster
Cassiopeia
7
00 43.6
+61 46
NGC281 Clust. Neb
Cassiopeia
7.4
00 53.0
+56 37
NGC278 Galaxy
Cassiopeia
10.8
00 52.1
+47 33
NGC381 Open Cluster
Cassiopeia
9.3
01 08.4
+61 35
NGC436 Open Cluster
Cassiopeia
8.8
01 16.0
+58 49
NGC457 Open Cluster
Cassiopeia
6.4
01 19.5
+58 17
NGC559 Open Cluster
Cassiopeia
9.5
01 29.5
+63 19
NGC637 Open Cluster
Cassiopeia
8.2
01 43.1
+64 02
NGC654 Open Cluster
Cassiopeia
6.5
01 44.0
+61 53
NGC659 Open Cluster
Cassiopeia
7.9
01 44.4
+60 40
NGC663 Open Cluster
Cassiopeia
7.1
01 46.0
+61 15
NGC40 Plan. Nebula
Cepheus
10.7
00 13.0
+72 31
NGC188 Open Cluster
Cepheus
8.1
00 47.5
+85 14
NGC781 Galaxy
Pegasus
10.6
00 03.2
+16 09
M76
Plan. Nebula
Perseus
11
01 42.3
+51 35
M74
QUICK VIEW DIARY 1 7 14 15 21 27 29 30
Sunrise 06.54h : Sunset 16.39h Moonrise (13h) Moon: First Quarter (20h) Moon at perigee – nearest to Earth in its orbit (11h) Full Moon (14h) Hunters Moon (trad. English) Moonrise (17h) Aldebaran 0.5°S of Moon (17h) Moon: Last Quarter (09h) Moonrise (23h) Moon at apogee – furthest from Earth in its orbit (20h) Moon rise (07h) New Moon (12h) Sunrise 07.42h : Sunset 16.02h
NOVEMBER MOON PHASES
Galaxy
Pisces
9.4
01 36.7
+15 47
NGC128 Galaxy
Pisces
11.8
00 29.2
+02 52
NGC488 Galaxy
Pisces
10.3
01 21.8
+05 15
NGC524 Galaxy
Pisces
10.3
01 24.8
+09 32
M33
Galaxy
Triangulum
5.7
01 33.9
+30 39
NGC672 Galaxy
Triangulum
10.9
01 47.9
+27 26
PATRICK’S PITHY PEARLS OF ASTRONOMICAL WISDOM
“Voyager 2 got to Uranus less than two minutes late after a journey of billions of miles. British Rail please note.” * “There’s only one man we really need in parliament today: Guy Fawkes!” *
The Moon is a nice large, bright object to observe at any time of the year – observing our nearest satellite on a balmy summer evening is a great experience. The main problem however is that the ecliptic path the Moon follows is low in the southern sky during summer nights. With the passing of the Equinox at the end of September, the Moon’s path through the night sky has begun to increase in altitude and it becomes a more prominent object for telescope users. The Full Moon this month is the ‘Hunters Moon.’
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The Southern Astronomer No.98 – November 2016
OBSERVING THIS MONTH:
M
PLANETS
id month, most of the planets in our solar system are in the evening or night sky this month – only one is visible in the morning.
At the start of the month, Mercury rises shortly after the Sun and sets a little after sunset. By mid month it rises well after the Sun but it still sets about 45 minutes after the Sun making it a difficult object to observe, though a good south-westerly horizon and a clear sky will give one a chance a view of this elusive little planet.
Visibility of the planets and Moon, mid-month
The other inner planet, Venus on the other hand will be much more of an easier object to observe as it slowly makes its journey in its orbit. Even in a small telescope it is taking on a gibbous-moon phase. The angular diameter of Mars is getting slightly smaller and a moderate to large instrument will still show the dusky markings on the planet. The one drawback is it is low in the sky. It is visible in the south-west after sunset but sets just after 21h. Saturn is close to the Sun setting at 17.35h – just an hour and a quarter after the Sun. The best views we’ll have of this planet will be in the dark morning skies of late January.
View of the inner solar system mid-month
For the early birds among us, Jupiter is on show in the predawn skies during the month. Its angular diameter is 33’.1 and it will shine at a bright -1.7m making it a bright morning star during the early winter. Despite the small present angular diameter – it was 44’ at opposition earlier this year – a small telescope will show the four bright satellites and the belts. Even a pair of binoculars will show the little moons and the pronounced polar flattening. In the predawn sky on the morning of November 25 it will be west of the waning crescent Moon. The planets mid-month (comparative angular diameters) – timed at 21.30UT
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The Southern Astronomer No.98 – November 2016
OBSERVING THIS MONTH:
THE MOON THE MOON ILLUSION
A simple experiment is to photograph the rising Full Moon against some recognisable horizon object, say roof tops. To the eye the Moon will look extremely large when compared to the rooftops. Take a picture and view it and the Moon looks suddenly a lot smaller (assuming you are using a standard lens and not a telephoto or zoom.)
A
s has been mentioned previously, the Full Moon and its perigee coincide closely on November 14.
During the period around Full Moon, the lunar section, request further observations of Aristarchus – just prior to Full Moon on November 13, 20:39-23:51 – are the interior bands more prominent in red or blue light? After Full Moon on November 15, 18:1518:36 – detailed colour images showing the floor needed and,the following evening 20:53-21:06 – are the bands inside the crater steady in appearance?
This is not unusual. It happens every 13 months or so; an unusual event in 2015 was that this occurred at a time of a lunar eclipse as well. Not so this year; it is just a straight forward perigee Full Moon. During our northern summer, the Full Moon rises late but with winter now upon us and early sunsets, the rising Full Moon is much more conspicuous to people especially as this coincides with the commute home. Many people mention how large the Moon looks and this is often described as ‘The Moon Illusion.’ It has been noted throughout time in various cultures but the mechanism of it is still debated however, it almost certainly agreed that the observers eye/brain system is being fooled by an optical illusion.
The Ebbinghaus Illusion is just one theory as to why the Moon Illusion appears to work. The lower central circle is surrounded by small circles and represent the horizon Moon accompanied by objects of smaller visual extent, while the upper central circle represents the zenith Moon surrounded by expanses of sky of larger visual extent. Although both central circles are actually the same size, the lower one looks larger to many people.
William Herschel believed this crater was an active volcano when he observed its unusual brightness in earth shine but we now know this to be the result of bright lunar material reflecting the light of the earth. During the late afternoon of November 3 between 16.28 and 17.19 try and take a look at Aristarchus with the largest magnification you can – can you see colour? If so the the lunar section of the BAA would like to hear from you.
The reason for these observational requests is that in the past observers have reported unusual appearances in the crater and the libration and illumination at the times on the dates above near duplicate those of the original observations. It is most probable that atmospheric conditions caused the original observers to see what they saw, but the topography, and albedo effects of the lunar surface itself might also play a large part. Observing lunar features that have had © Andy Lee strange effects observed in them can lay these lunar ghosts to rest, once and for all. The picture by Andy Lee above shows a photographic Moon Illusion caused by the Aristarchus is not alone: November 8 at use of a telephoto lens – a trick used by the 21:28-23:26 Clavius – images or sketches main stream media when presenting items needed, covering the area between craters about the perigee Moon effect. A and B and on November 9 at 21:49-22:40 Conon – can you see/image a faint light spot If nothing else, the Moon Illusion gives a on the floor of this crater? dramatic view of the Moon’s relationship with our surroundings. The above are just a few of the many examples that the BAA Lunar Section lunar geological change detection programme OBSERVING: LUNAR GHOST HUNTING under take each month and it is quite rewarding. Can you help? The Moon is new on October 30 so by the start of November the young crescent Moon DAYLIGHT OCCULTATION will be hanging low in the western sky after sunset. As the Moon crosses the sky it eclipses stars, asteroids and even on occasions, When looking at this young Moon, it deep sky objects. It follows therefore that the becomes apparent that the night portion of it Moon will also eclipse a planet occasionally. can be seen shining very faintly next to the These eclipses of celestial objects are brilliantly lit crescent. The dim glimmer is the referred to as lunar occultations. result of light being reflected off of the Earth by the Sun and bathing the lunar surface in On the afternoon of November 9th the rising ‘earth shine.’ If we look at this night portion Moon will pass over the planet Neptune. The of the Moon with binoculars or a telescope disappearance of Neptune occurs while the with a low power magnification, we can Moon is below our horizon but its sometimes make out the ghostly outlines of reappearance happens when the Moon is some of the brighter lunar features. low in the eastern sky. One of the brightest of the lunar features is a The planet Neptune will pop into view at the crater called Aristarchus on the north-west Moon’s eastern edge (the lit portion) at just quadrant of the Moon (approximately by the about 14h. Sad to say Neptune is nearly 8m right-eye of the ‘Man in The Moon.’ and the sky will be too bright to see this event occur – or will it?
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The Southern Astronomer No.98 – November 2016
OBSERVING THIS MONTH:
THE SUN
T
he Sun rises later and sets earlier over the next few months so the chances of observing the Sun for the average wage slave (like me) is pretty slim with weekends being the most opportune time to observe it and there is the question of it being clear on top of that. When the Sun does shine it can be an interesting object to observe when using SAFE AND CAREFUL PRECAUTIONS! When I started out in astronomy, nearly fifty years ago, there was only one safe way an amateur could safely observe the Sun – via the projection method, where a white screen is held behind the eyepiece and the image formed in the eyepiece is projected onto the screen. If this is attached to the ‘scope and shielded from sunlight, the better as the writers own projection set up below, shows.
This has always been considered to be the safest way as the direct light from the Sun which also includes heat and other radiation which will otherwise destroy the eyesight of an unwary observer is scattered onto a piece of white card.
I remember seeing the price of these in the old Sky & Telescope magazines during the early 1970’s and their dollar price equated into hundreds of pound sterling making them well beyond the grasp of a school boy. The other type of device was something called a Herschel Wedge – an inverted Tshaped eyepiece, where the light from the Sun was reflected into the observers eyepiece via a piece of specially shaped glass while the heat passed through the rear of the T and away from the eye. A piece of dark glass was needed just to reduce the glare of light from the Sun. These were difficult to get hold of due to them having gone out of fashion.
popular and though moderately expensive it is another useful tool for the amateur solar observer to use. I still use the projection method for daily (whenever possible) sunspot position and number recording, while I use the ‘wedge’ for imaging detail in interesting sunspot groups (below.) RECENT SOLAR OBSERVING As many readers will know, sunspot activity has been very quiet but during October there were a few moderate sunspot groups that made themselves known.
Things changed in the late 1970’s. Technical developments in the way metals and plastic could be combined had been resolved and a plastic film with a metallic finish called Mylar started to become readily available. By using science grade Mylar, astronomers in the US were able to make their own aperture-filters for a fraction of the cost of a metal on glass job. Other science equipment manufacturers got onto the bandwagon, and solar-foil (as it became known) was readily (and cheaply) available and the original Mylar type was improved upon. The sheets can be bought in large sizes so telescopes not even capable of solar projection, like the Schmidt© Brian Halls Cassegrain can be used for looking at the One such small but active sunspot was Sun safely. observed on October 9 (above). This image was captured using an Imaging Source camera (basically an enhanced science web-cam capable of filming fast frame rates) to shoot an AVI movie file which was then processed in Registax to create the final picture. I used a wedge with a solar continuum filter (540nm) to enhance the solar photosphere around the spot. Colour was added using GIMP. The telescope was a 152mm refractor at full aperture and f16.
Telescopes were often sold with a ‘solarfilter’ that would screw somewhere into the eyepiece – these certainly blocked the light but NOT the radiation and due to the intense heat, they could crack without warning. No The writers 102 mm refractor with solar-foil filter wonder astronomy popularisers like Patrick Moore would rightly tell us to throw these It may come as no surprise, the manufilters away before they could be used. facturers of metal on glass solar filters which were soooo expensive started to sell their There were however some exotic (and very filters much more cheaply. Metal on glass if expensive) additions to the telescope that looked after, will last perhaps a life time of could be used for safe solar observing. The astronomy use; solar-foil however being first of these was a metal on glass filter that plastic will degrade no matter how well fitted over the front-end of the telescope. looked after and these need to be replaced This kind of device, called an aperture-filter every few years or so. I used mine regularly blocks both the glare and radiation so for imaging and I got about four years out of making direct observing through a telescope it before I upgraded to…..…. the Herschela safe experience. Wedge which has once more become very 6
As I write, it is a bit too early to say how October compares with September in the sunspot stakes but it might be that October is a slightly more spottier month than the one previous. Nearly all sunspot activity, like the last few months, was in the northern solar hemisphere. SEPTEMBER RESULTS Brian States observed the Sun on 27 days while I did only 8 days. The joint average daily sunspot number for us was 37.2 which compares with BAA 33.8; AAVSO 36.2 and the SDC 44.7 ALWAYS TAKE GREAT CARE WHEN LOOKING AT THE SUN.
The Southern Astronomer No.98 – November 2016
METEORS & COMETS NATURES OWN FIREWORKS
T
he major meteor shower at this time of year is the Leonids. Beginning at about November 6, they go on until the end of the month with the maximum of the shower occurring about 06h UT on November 17. The radiant – the point where the meteors appear to emanate from – is 60° altitude and due south about the time of maximum and is in the ‘sickle’ asterism (or backward facing question mark) that is the Lion’s head. The Moon will be several days past Full and will also be high in the sky so moonlight makes this an unfavourable maximum to observe.
sun-beds or deck chairs which can be employed which allow the observer to lean back comfortably and look up into the sky is really useful and saves cricking your neck. A good overview of how to observe meteors is written by Dr John Mason of the Chichester Planetarium and BAA Meteor Section Director and can be found here. There are links also for suggestions on group observing as well. Photography has always been an aid in meteor observing and digital photography has made it that bit more easier. A good camera, wide angle lens and steady support for the camera are needed. For digital equipment, make sure batteries are fully charged and an old clean towel that can be placed over the camera when it is not in use to protect it from dew. Pictures should be set for high quality JPG or preferably RAW format.
At maximum, it produces a moderate hourly average (ZHR) of 15 meteors. This shower has produced some intense and amazing meteor storms in the past, though this is not forecast for 2016. The ZHR in 2008 for example reached a peak of 99. The Leonids are the dust trail of comet Temple-Tuttle.
If taking a sky shot ensure that stars can be later identified using a star atlas – this is useful when two or more observers at Meteor train – 13/08/16 © Alex Vincent different locations may capture the same object on an image and of course comparing Sometimes a rare view of the ‘smoke’ trail of the brightness of the meteor with stars of a meteor can be seen and pictured as in the known magnitude. above image. Not all meteors produce them but they can be quite stunning as you can A lesser known shower is the α-Monocerotids The time of the image – this is date stamped see (above.) which start about November 11 and go on until the 25th with a maximum on the morning in the metadata of a picture but allowances for BST and UT must be allowed for and the of November 21. The ZHR of this minor shower can be variable though in the past it time should at least be set to the nearest minute. Ideally the file should be named in a to has produced intense but short meteor storms. The progenitor comet of this meteor format such as yyyy-mm-dd UT tt.tt – and finally, the name of the observer (you!) shower remains unknown. Indeed, little is known about this shower so observations The late summer Perseids gave our and/or images of meteors are most members some treats both observationally welcome. and photographically. At the close of the month, a more ‘reliable’ meteor shower with a similar name Monocerotids – starts on November 26 and peaks in early December. The Orionids meteor shower which started and peaked in October comes to an end in early November. OBSERVING How does one go about observing meteors? Meteor observing as part of a group can be quite rewarding (and fun) though many regular meteor observers will also observe solo.
© Alex Vincent
Observing meteors can be interesting as well as fun – and indeed, this unusual aspect of astronomy which does not rely on telescopes or expensive equipment can be rewarding as any other aspect of astronomy.
Apart from the obvious clear skies, patience is something that an observer needs. At anytime of the year dressing to keep warm is important for any aspect of observational astronomy and so it is with meteor observing. Being comfortable is also important. Old
Clear skies! The Pleiades and Perseid 2016
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The Southern Astronomer No.98 – November 2016
WORKSHOP REPORT
T
October 4, 2016 he format for this meeting was unusual – apart from it being the AGM.
colour and variable chip sizes and adaptability to give differing final image size. After the tea-break when many members were able to chat about more detailed technicalities with John and Zoltan, we had our AGM.
We had hoped for a three handed presentation but sadly one of the speakers was unable give his talk which has now been planned for another date. Instead we had a two hander with members John Bush and Zoltan Trenovski. As many will know, John is a planetary, lunar and solar imager (his work has graced these pages of The Southern Astronomer in the past.) The picture above shows a typical setup. John began by describing how astronomical imaging had become far more easier to perform rather than in the ‘good old days’ of film photography. What is required? Telescope – long focal length and high f-ratio - Celestron or Meade Schmidt Cassegrain telescopes are ideal as they are about f10. Planets are very small and need f25 to f30 to increase size – a barlow lens is often employed to increase magnification; if a native f10 telescope is used, then 2x or 3x barlow lens is needed.
John then described a typical imaging session – aligning and focusing the telescope, and then ‘shooting’ a video sequence. Once the image (or group of images) are saved to the PC they can then be processed at leisure – a cloudy night is useful! John uses Autostakkert 2 to process the images and is recommended by imager, Damien Peach. John then tweaks the final image using Registax. A final result is like the one of Jupiter below.
A mount able to track planet (motor driven or with GOTO); the camera which does not take a single picture but a video of the planet with multiple frames using CCD/CMOS chip. Suitable laptop – to run the specific software at the telescope and some form of processing software – to align and stack good frames to make a final image.
Jan Halls, as Treasurer, gave a report on our financial situation which was quite well. There had been a small drop in income this year, in part due to a decrease in donations and the hire of speakers, but basically a healthy financial situation. The figures were proposed and seconded and accepted by the meeting. Chris Pennells who had kindly audited the figures for this year, agreed to be the auditor for 2016/17. Brian Halls as acting joint co-ordinator gave a resume of the year and thanked all those who had helped in the many varying ways which all helped make the group a success. Thanks to Chris Pennells for auditing and organising refreshments and the projector for the meetings; Perry Wilkins for maintaining the website and improving what it can do. As for officers of the group, no nominations had been received; the acting core group of Co-ordinator, Treasurer, Web Master, Newsletter Editor were returned. It was highlighted however that if at anytime someone would like to put themselves forward (or be put forward) for any rôle, they would be welcomed. The final portion of the evening was a review of some of our members observations and work done since the last Workshop night. A wide variety of images of Perseid meteors was shown – the number of high class images show the enthusiasm of members of the group for recording events like this and the quality also shows the pride that members take in their work.
Jupiter and satellite
A useful accessory is an imaging flip mirror such as the one above. The attachment to the telescope is on the right; the camera connects to the left. At the top of the assembly is the eyepiece which the observer uses to align and focus the object – say a planet, via a flip mirror. This simple arrangement is useful.
© John Bush
Both Autostakkert and Registax are free to download from the internet.
A mixture of recent planetary, lunar and solar images were also shown.
The same processes can be used for the Moon or the Sun, though for the latter a suitable aperture filter should be used (see page 6.)
The meeting was closed and we meet again for the next Workshop on December 2 which will be the Christmas and New Year meeting which will be a light hearted affair with free entry, refreshments, festive bites and some presentations of members recent images and a preview of what is happening in the sky in 2017. And a chance to socialise.
The second portion of the presentation was given by Zoltan who described the differing types of camera made by the ZWO Optical Company of China which are rapidly becoming the camera of choice for many planetary, lunar and solar imagers. Cameras can be either monochrome or
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Our first Workshop in 2017 we hope to have a hands on technical workshop – Telescope & Equipment clinic when we get to find out how some of our stuff works!
The Southern Astronomer No.98 – November 2016
T
LOOKING UP: NOVEMBER NIGHT SKY he dark evenings are truly with us now and on a clear night the night sky is full of stars.
Mid-month (the date for which our star charts are set for,) sees a Full Moon which will curtail the search for fainter deep sky objects but the first week and and a half of November and the last ten days of the month will not be so affected by moonlight. Almost overhead early in the evening is M31, the Andromeda Galaxy laying in the constellation of Andromeda at a distance of just over 2.5 million light years. The angular diameter of this object is just over 3° or about 6 moon-widths; its magnitude is about 3.4 and even from a moderately light polluted site it can be seen as a faint fuzzy patch in the night sky. Binoculars and small telescopes will show the fuzzy outline of this nearby galaxy to us – larger instruments with wide field eyepieces will show some of the brighter stars.
The Andromeda Galaxy
© Rob Aro
For amateurs interested in astrophotography it is a favourite object to image and is a also good object for the newcomer to imaging. The picture top right is a recent (October 2016) image by Rob Aro. There are other deep-sky objects. Where as M31 is a distant galaxy like our own Milky Way galaxy comprising billions of suns, there are some more familiar objects which are by comparison nearer to us. The open star cluster M45 – The Seven Sisters or Pleiades – in Taurus is not far from the Moon during the middle of the month but even bright moonlight will not hide away this small cluster of stars. The position of the recent October Nova
© S&T
but of course, it is easier to find during the early part of the month and after Full Moon.
Two areas of great nebulosity which is observable is M42 – The Orion Nebula, and Barnard 33 or the Horsehead Nebula just Over head, the portion of our Galaxy we refer below the left hand star – Alnitak - in the to as the Milky Way runs from south-east to Belt of Orion. Close by is NGC 2023 which north-west and contains many fine deep sky is reflection nebula. objects, especially around the constellation of Cassiopeia and locations of these objects We will no doubt be coming back to these can be found on page 3. objects over the coming months.
M45 © Andy Li This is a fine object for binoculars or small telescope with a low magnification which show far more stars than can be seen with the unaided eye.
A good detailed star chart will identify them but perhaps the easiest is to use Stellarium the free online planetarium software which will help locate some of these objects.
Rising in the south-east during the middle part of the evening is the familiar Orion Another nearby open cluster of stars, though constellation. This is an area of great not so obvious as M45 is the Hyades, close nebulosity though for visual and indeed most to the star Aldebaran. As mentioned earlier, imagers, this nebulosity is beyond the reach of amateur equipment. mid-month, the Moon is in this area of sky
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On October 20, a nova was reported in the constellation of Sagittarius near to the asterism of The Teapot. Member Andy Lee heard about the nova popped to the beach to see if he could capture it on camera. He describes it as “a tricky one as it's low down in the south east sky as the sun sets...” Andy’s image which he has labeled up is on the front cover of this issue.
The Southern Astronomer No.98 – November 2016 What is a nova? All classical novae are close binary stars with a compact white dwarf stealing hydrogen from its larger but weaker companion. The gas ultimately falls to the surface of the dwarf, where its piles up on the star’s surface. It becomes compacted by gravity and heated until hydrogen fusion ignites. The layer explodes like a hydrogen bomb in the shape a thin shell enclosing the star. This is what you see when you look at a nova – basically, a gigantic bomb going off! The underlying white dwarf survives intact, and the process of stealing matter from its larger companion starts all over again. A star can brightens by 50,000 to 100,000 times in a matter of hours, becoming luminous enough for it to be observed on Earth. There are many periodic novae that suddenly flare up – some can be quite regular while others will flare suddenly and then disappear until the next time which in some cases may not be for generations.
October Night Sky around 21.30 mid-month
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