The Southern Astronomer by Brian Halls

The Southern Astronomer No.70 – July 2014

SOUTHERN ASTRONOMER THE

NEWSLETTER OF WORTHING ASTRONOMERS & WORTHING SKYWATCHERS

This issue The One to Watch This Month 1 The One to Watch This Month 2 Workshop Evening FTA:National Astronomy Week Observing Notes

front p.2 p.3 p.4 p.5

Astronomy Meetings All the groups listed below begin their meetings at 19.30hrs BST

THE ONE TO WATCH THIS MONTH (1) Appulse and Pairs As mentioned in the June issue, two minor planets, 1 Ceres and 4 Vesta get very close together in the sky. This sort of event is known as an appulse. On July 5 the objects get to within 10 arcminutes of each other (about third the diameter of the full Moon). This is closest they have got since 1800.

Worthing Astronomers (WA) meet on the first Friday of the month, every two months (February, April, June, August, October and December) at Goring URC, corner of Shaftsbury Avenue and Barrington Road, Worthing, BN12 4EA. Admission £3. Adur AS (AAS) meet at Southwick Christian Community Church, 1-5 Roman Crescent, Southwick BN42 4TY.Admission: £5 for guests, £3 for members. ADUR DO NOT MEET IN JULY Foredown Tower Astronomers (FTA) at Emmaus Charity Premises, on the corner of Manor Road and Drove Road, Portslade Old Village, BN41 2PA. Admission £3 for guests. Worthing Astronomical Society (WAS) meet at Heene Community Centre, 122 Heene Road, Worthing BN11 4PL. Admission: £4 for guests. AAS, FTA, venues have off road parking facilities and grounds adjacent for setting up telescopes when conditions allow. WA members will always be made welcome at these groups. More information 01903 521205 or 07801 692244. Fuller details of what our colleagues in neighbouring societies are doing at their monthly meetings is in the Quick View Diary, page two, A star map showing the relative positions of Ceres, Vesta, Spica and ζ (Heze) July 4 Worthing Astronomers is a free to join society with a membership of over 300, all interested in the same hobby of Astronomy. With the aid of this newsletter, 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 neighbouring societies.

Chart: Carte du Ceil

Richard Miles of the BAA writes: “The Ceres-Vesta appulse...is an unrivalled opportunity for anyone equipped with a DSLR camera to participate in a project to measure colour changes in images of Vesta. To do this you should take a series of images in RAW mode spanning several hours to capture both bodies in the same field of view. The longer the time-series, the better, as you will have to wait 5.34 hours for Vesta to rotate once. What is most important is that the exposure time used should not saturate pixels in the image of Vesta, which will be about 7m. To avoid this, set the camera on a low ISO setting (say 100 or less) and defocus slightly so that the stars are small discrete blobs – that way you can use a longer exposure without reaching saturation. The most difficult part of this project will probably be the analysis of the images. The idea is to secure images in three filters, and a DSLR does this in a single RAW shot by

The Southern Astronomer No.70 – July 2014 Appulse and Pairs continued

providing red, green and blue (RGB) images which can be saved separately and converted to FITS files for analysis.” Ceres will be about 8.4m while Vesta will be 7.1m If you are thinking of taking part in the programme described by Richard Miles, I would begin by getting some test exposures made to determine the best for the session; once you are sure you have the right exposure time for your camera, keep to it and set up the focus etc. as described in the piece above and get as many exposures as is possible over a given length of time.

Ceres and Vesta on July 4 – x30 non-inverting eyepiece The bright star to the right is HIP 65840

The closest approach is early Saturday July 5, though the previous night (July 4) will also afford a good opportunity. Ceres and Vesta will still be close on the Saturday evening.

QUICK VIEW ASTRO EVENTS DIARY

July All times shown are Universal Time (UT = BST minus 1 hour) For AAS, FTA and WAS details, see front page 1 Sunrise 0353h : Sunset 2022h 4 Earth at aphelion – furthest point in orbit from Sun (03h) 5 Appulse of Ceres and Vesta Moon: First Quarter (11h) 6 Mars 0.2°S of Moon (01h) 8 Saturn 0.4°N of Moon (01h) 12 Full Moon (11h) BAA Summer Meeting: The Observing Life and Times of Sir Patrick Moore 13 Moon at at perigee (08h) 14 Mars 1.3° N of Spica (01h) 16 WAS: TBA 17 FTA: The Plumes of Enceladus 19 Moon: Last Quarter (02h) 24 Jupiter at conjunction (20h) 26 New Moon (22h) 28 Moon at apogee (03h) 31 Sunrise 0426h : Sunset 1953h

THE ONE TO WATCH THIS MONTH (2) Comet C/2014 E2 (Jacques) is scheduled to make a return visit to our early morning sky during mid month but it will not become really visible until the end of the month, though it will form a triangle with Mercury and Venus before sunrise on July 13. A good view of the southeast horizon is recommended. It will be close to Venus both figuratively and physically – passing the planet at about 12.7 million km on that day.

A BRIEF HISTORY OF MINOR PLANETS This pair of Minor Planets (or asteroids to use their common name) were among the first of their kind discovered at the start of the nineteenth-century. The first was Ceres (1 Ceres) discovered on January 1, 1801; followed by 2 Pallas, March 28, 1802 and 3 Juno September 1, 1804. The fourth was Vesta (4 Vesta) on March 29, 1807.

As the month progresses, and as sunrises get a little later each day, the comet will become more apparent in the dark hours of the early morning. There is a predicted magnitude of about 4.

The Minor Planets Center who keep tabs on these objects, now have over 281 000 asteroids in their database.

All this of course assumes its perihelion passage on July 2 goes well; the last 'famous' comet to become unstuck at perihelion was ISON in late 2013 when the Sun vaporized it at closest approach. We are not sure how 'Jacques' will fare by comparison; it appears to have a denser coma than ISON but at the moment the rate of out-gassing is not known. All these factors play a role in the way the comet appears in our morning skies during the summer if it does at all.

C/2014 E2 (cross-hairs) south-east horizon before sunrise July 1 Graphic: Stellarium

Next Month: August 18 - Jupiter and Venus morning conjunction

Vesta as imaged by the Dawn spacecraft © NASA/JPL

The Southern Astronomer No.70 – July 2014 WORKSHOP EVENING June 6 FOR THE BEGINNER: TELESCOPE TYPES Refractor: A telescope that uses a lens to bring an image to focus in an eyepiece. Everyone is familiar with the spyglass-type telescope, which is a type of refractor. The first telescopes were of this type but used lenses in a manner that is very different to the refracting telescopes we use to day. The modern telescope is of two types – the achromatic and the apochromatic (sometimes referred to affectionately as an 'apo'). Early telescopes were plagued by something called 'chromatic aberration' causing an image in the eyepiece to have vivid red and blue fringing. To get over this refractors had to be unusually long – one telescope was 150-feet long and had to have its lens end hoisted up a mast!

Brian Halls We held our second Workshop of the year at the Cornwall Room of the Goring URC. The theme for the evening, organized by Steve Bassett, was a Telescope Clinic where members could ask questions, answer questions and clear up those nagging queries that we all have. In that respect it was a good night. Thirty-seven members and guests attended with several members bringing along their instruments – a wide range of types and manufacture of telescopes. Hants Astro's Bob Leggatt's 250mm Newtonian SkyWatcher telescope with GoTo Dobsonian mount certainly got a lot of interest from those attending. A selection of telescopes showed those attending the varied and wide selection of differing instruments ranging from a GoTo controlled Dobsonian-Newtonian to a Schmidt-Cassegrain telescope mounted on a GPRS mounting.

Pictures: Brian Halls (right) and Steve Bassett (lower)

Then came the invention of the achromatic lens – actually two lenses made of flint and crown glass which bring two wavelengths of light – usually red and blue – to focus at the same point thus reducing very much the chromatic aberration of earlier times. This sort of lens assembly is known as a doublet. Telescopes became much shorter, manageable and importantly, cheaper. Chromatic aberration however remained a problem and this led to the development of the apochromatic. These refractors use highly engineered and pure (thus costly) crown and flint glass in their lenses which cancel out the small amount of chromatic aberration the achromatic suffers; all the colours are bought to a single focus. The modern apochromatic refractor is often double (and often much more) the cost of a similar sized achromatic telescope. The 'apo' doublet lens has been around almost as long as the achromatic – it was invented by Peter Dolland in 1763; the son of John Dolland who patented but did not invent, the achromatic system in 1758.

Ideas regarding observing as well as sourcing some of the accessories that members have as part of their respective kits were talked about – almost certainly some spending by those enthusiastic telescope users amongst us that evening will follow this meeting! There was a discussion also among members regarding observatory building – one or two back garden observatories are in progress – one a roll of roof type while another member is contemplating a dome type. A good night for all and many thanks to contributors for bringing the interesting array of different types of telescopes and to Steve for arranging the workshop. Ideas for future workshops always welcome – contact details inner back page.

The Southern Astronomer No.70 – July 2014 NATIONAL ASTRONOMY WEEK Foredown Tower Astronomers George Hurrion George Hurrion writes about our colleagues at Foredown Tower Astronomers (FTA), and their perspective of National Astronomy Week. Details of where FTA meet can be found on the front page of this newsletter.

The National Astronomy Week Jupiter Watch was extremely successful in delivering an introduction to astronomy to our local public who were the important element in the event. National Astronomy Week is a free standing event not caught up in the glaring publicity given to Stargazing Live by the BBC.

It was real, they could use a telescope live, ask for eyepieces to be changed for greater magnification, etc. Robin was told about two comments that were made and he said "please give those in a feed-back.” One came when we were setting up the telescopes, one of the Companions of Emmaus said: "Do you know there is a black dot on the viewer." He had seen one of the Moons in transit. We had not mentioned this to anyone to avoid any viewing complication. Another Companion who had never looked through a telescope made an observation that had eluded some of the experienced observers.

Our astronomy group Foredown Tower Astronomers meet at the Emmaus Community, an international charity based in Hove that provides a home for people that have become homeless for one reason or another. The speaker for our May meeting was Dr. Robin Gorman, who was responsible for National Astronomy Week. We told him about our involvement with this event and he asked that we make known our contribution to the event known to other astronomy groups.

The second remark was a thank-you from one young lady. She said: "I always hated clear nights when I was sleeping rough on We held our event over three days in the grounds of the Emmaus the beach because it was going to be cold. Thank you for giving Community and during that time 150 visitors came and amongst me a new look at the night sky, it is wonderful." that number was a teacher from a local school who asked if we could take our telescopes to their school one evening to give the A follow-up from National Astronomy Week is that the school children a chance to see Jupiter. We did this on the last day of mentioned above has asked if our group can supply an the event on Monday, making a total of four days "Jupiter astronomer to give a talk about the Solar System to the whole Watching." school as an end of term treat. It was not the 150 visitors who came to the three -evening event Many thanks are due to Robin Gorman and National Astronomy or even the large turn-out of the schoolchildren on the Monday Week. that gave Robin Gorman the “wow” factor. This came from the remarks of the residents of Emmaus who said that this was most Long may it continue. revealing for them. George is the chair of the FTA. Further information about the work of the Emmaus organization can be found here: http://www.emmaus.org.uk/

Noctilucent clouds captured at about 3 a.m BST, June 20, from Worthing © Chris Pennells

The Southern Astronomer No.70 – July 2014 OBSERVING NOTES July All times are expressed as Universal (UT) and can be considered the same as GMT (BST minus 1 hour) Information, unless otherwise stated is for the 15th of the month

BEWARE OBSERVING THE SUN IF YOU ARE NOT SURE HOW TO DO IT SAFELY - THEN DON'T!

OBSERVING THE SUN As many of you may know we have have open days at our observatory for solar observing so members can come along, see what is happening on the Sun and look at safe methods of solar observing. In the past, this has coincided with the April Sun Day events of Global Astronomy Month. Lunar and planetary visibility mid-month

The evenings are now beginning to get darker a little bit early night to night – the Sun sets about half an hour later at the end of July than it does at the beginning of the month. Sunspot activity on the Sun has remained moderate over the last few months. Notably, the southern solar hemisphere has seen the majority of this activity though a few northern hemisphere sunspot groups have been around. In the unusual image on the left, four sunspot groups have been captured as they approach the western solar limb. Highly active sunspot groups 2084 and 2085 can be seen in the lower part of the picture. These magnetically complex sunspot groups when observed in normal white-light comprised many small sunspots and it can be seen in the picture that there were active in other frequencies of light as well.

Not for the first time, this year was clouded out. So as not to disappoint we have decided to open the observatory up on any Sunday it is clear and the Sun is shining, to any member who would like to pop along and see how we do it and what is going on. Solar projection and SAFE direct solar observing methods will be demonstrated plus, depending on seeing conditions views of the Sun through a hydrogenalpha telescope will be seen. If you are interested and of course to make sure that we are home – it is a weekend and we may be doing something else - call 01903 521205 or 07801 692244.

Stuart Hillaker used a Coronado PST telescope to capture this solar image – and he used the addition of a neodymium filter to create the rather unusual texture. The use of specialised filters and coloured planetary filters in solar observing will be discussed in a future article. June 12 (h-alpha image) © Stuart Hillaker

During May, members reported observing the Sun on 27 days – well done Brian States. Between us all the relative average daily sunspot number for the month was R 93.35. The Moon is lower in the sky during the summer but it easily visible in the light evening sky Above - projecting the solar disk onto a and many features can be seen before darkness. In some ways this is a good time to observe piece of white card – a really safe way of observing the Sun in comfort. It also as the eye is not dazzled by the harmless glare of moonlight. Anyone wanting to under take allows several people to look at the Sun at astro-imaging can do no worse than practise on the Moon. It is a forgiving body so now is a the same time. good time for getting used to camera set-ups and checking for the best combinations of © Brian Halls camera, barlow lenses etc., focus points and exposures ready for dark nights to come. Mercury returns to the morning sky mid-month, rising about 02.41UT. From the Earth view point, Mercury takes on a 'half-moon' look (actually a 43% phase). You will need a very good south-south-east pre-dawn horizon to see the planet however. Its relationship in the sky

The Southern Astronomer No.70 – July 2014 Observing Notes continued

with Venus is shown in the diagram on page 2. Venus is, of course another pre-dawn object rising at about 02.05UT. Over the last few months it has changed from a half-moon shaped object to a 'gibbous' phase – the phase is 88%. An early riser in the morning with a conjunction – with regards to objects appearing to be in close proximity to each other good south-easterly sky and a moderate telescope will make out the phase well. ASTRO LINGO

as seen from another view point in space – Earth. On July 24 Jupiter is in conjunction with the Sun as seen from the Earth. Jupiter will be at the furthest point of its orbit as seen from the Earth with the Sun laying in almost line of site between us and the planet. Schmidt-Maksutov – the idea for a Maksutov telescope came to its inventor Dmitri Maksutov, while riding on a refugee train in 1941 as he escaped Leningrad. His telescope uses a concave corrector plate as a lens to throw an image on a spherical mirror – the mirror throws the reflection onto a internal silvered centre-piece on the internal portion of the corrector plate. The image is then reflected into an eyepiece centred in the spherical mirror. This 'folds' the light beam so a telescope tube could be shortened but still give a longer focal length. Relative positions of the inner planets to Earth and the Sun mid-July The Maksutov is now paired with other catadioptric designs such as the Schmidtcassegrain.

Graphic by C2A

At the end of the month Jupiter is in conjunction with the Sun and is not observable though many members took opportunities top observe it during this last evening apparition and many outstanding images were captured. On the evening of July 13, Mars will be just over a degree above the star Spica in Virgo. In a pair of binoculars or a small telescope with a low power eyepiece the red of Mars and the blue-white tint of Spica will make a pretty view. Despite the light evenings, Mars makes an interesting object to look at or even image. Several members have captured images of the planet (shown last month) - Andy Li has taken some excellent images using a colour webcam and his portable 5-inch Schmidt-Maksutov telescope.

A typical Maksutov application.

Unfortunately Earth is slipping ahead of Mars in its orbit and the angular diameter of Mars is shrinking – it is 9.5 arc-seconds at the start of July and ends as 7.9 arc-seconds. Saturn is a popular object to observe on a warm summer evening – the rings tilt towards us by 21o and the planet shines at 0.5m. Again members have caught some excellent images of the planet and its rings. The picture lower left by Andy Li – taken with the same set up mentioned above shows several features quite well. The planet has banded zones similar to that of Jupiter and the brighter salmon-pink equatorial zone shows very well. Andy (and others) have also captured the varying shades of the rings. It is easy to think of the system being made up of ringlets working their way out from the planet but it is more correct to think of it as an annulur disk comprising concentric brighter and fainter areas. The rings are visible in small telescope or even binoculars – with a low magnification they will look lobed (Mickey Mouse-ears) – the way Galileo first saw them 415 or so years ago.

Saturn, May 30 © Andy Li

Uranus and Neptune the final major outer planets of our planetary system rise late in the evening – 22.59UT and 21.51UT respectively.

The Southern Astronomer No.70 – July 2014

Friday, July 4th Sunday, July 6th Friday, July 18th Sunday, July 20th Friday, July 25th Sunday, July 27th Tuesday, July 29th Thursday, July 31st

7.30 pm Hubble's Glorious Universe 3.30 pm Summertime Stars, Moon and Planets 7.30 pm Saturn, Lord of the Rings 3.30 pm Those Magnificent Moons 7.30 pm Meteorites, Space Rocks and Impacts 3.30 pm Summer Skies, Shooting Stars 3.30 pm Violent Sun, Space Weather 7.30 pm Summer Skies, Shooting Stars Prices: Public shows: £6.00 for adults, or £4.00 for children under 16. Half-day courses: Please call for details.

Tickets may be reserved by telephoning the Planetarium on 01243 774400, or the ticket-line on 07818 297292. If we are unable to deal with your telephone request for information immediately, please leave your name and telephone number and the nature of your enquiry and we shall call you back as soon as we can. Tickets are also available, to personal callers only, from the Novium Museum in Tower Street, Chichester. As space in our star theatre is limited, visitors for the public presentations are strongly advised to book tickets in advance to avoid disappointment. PLEASE NOTE that we are unable to accept credit or debit cards at present. For public shows, payment is by cash or cheque, on the door on the day. Our public shows are suitable for children age 6 and upwards.

The Southern Astronomer No.70 – July 2014 Observing Notes continued

Uranus is a 5.8m object in Pisces. In a telescope it has green-hue. It lies about 2o west of εPisces mid-month. Neptune at 7.8m lays in Aquarius just over a degree and a half east of σ-Aquarius. Laying very nearly between them is the 12m galaxy NGC 7309. Neptune, as befits the planet named after the god of the sea, has a distinctive blue colour.

INTERESTING FACTS ABOUT LYRE

The Lyre is a harp-like musical instrument and in mythology it was the one owned by Orpheus who when he was killed by a Comets & Meteors: As mentioned on page two, C/2014 E2 (Jacques) will hopefully survive its group of outraged women (as one legend has it), his harp ended up in a river. Zeus encounter with the Sun and begin its journey out of the solar system. It is close to Venus on sent an eagle to retrieve it; both the bird July 13. and the harp were placed in the heavens as a reminder of this episode.

The Capricornid meteors are a group of three meteor showers that regularly appear in the summer skies and peak on July 8, 15 and 26 and are sometimes called the α-Capricornids due to the proximity of the radiant to that star. Mid-month the full Moon will interfere with views. The constellation Capricorn is low in the south. Bright yellow meteors are associated with this shower and it is associated with comet 169P/NEAT. The α-Cygnids produce meteors through much of the summer and commence about July 21 with a second peak a month later. The Perseid meteors are a famous annual shower and this year they are expected to peak at about 0h August 12/13. This peak in 2014 however is close to a full Moon (August 10) so the best views of any Perseids might be earlier on during the Perseid period which starts on July 23. More details about the Perseid's next issue. It is considered an unfavourable showing. Stellar & Deep Sky High in the eastern sky this time of year is the small constellation of Lyre. It lays to the west of neighbouring constellation Cygnus and recognizable by the bright (0.0m) star Vega which is one of the three bright stars of the 'Summer Triangle'. The other four bright stars in Lyre do give it a distinctive lozenge shape that is easy to make out.

Though M57 (see main text) was labelled as such by Charles Messier he was only the co-discoverer of the planetary nebula. Another Frenchman, Antoine Darquier also 'discovered' it. The term 'planetary nebula' is used to describe the appearance of the object in a telescope; M57 was described as looking like a fading planet. The Ring Nebula has the same sort of angular diameter as Jupiter in a telescope. With the eye at the telescope, it looks like a grey smoke ring frozen in time; it is only with photography the colours of the Ring are apparent.

To star hop around the constellation we find Vega, using the all sky chart on page 11, and then check out the star-hop constellation map on the page opposite. From Vega head south-west to the eclipsing binary double star Sheliak (β-Lyrae). The variability of this star was first discovered by the British astronomer John Goodricke in 1784. In a 12.9 day period it fluctuates between 3.34m and 4.34m. Compare it to the nearby γ (gamma) Sulafat. Astronomers are not quite sure as to the mechanism of the variability though it is suspected that matter is flowing from the primary star to the smaller companion at a rate of 300km/s. There was a suggestion some years ago the companion was actually a small black hole but this now seems exceedingly unlikely. Midway between β and γ is a faint oval patch about the size of the planet Jupiter in a moderate eyepiece. Charles messier gave it the number 57 in his catalogue (M57) and we know it by its more common name of The Ring Nebula (star-hop 2). What we are looking at is a cloud of gas expelled by a red-star during the latter stages of its evolution before becoming a white dwarf star. At about 2 300 light years from Earth the cloud is reckoned (by using spectroscopic analysis) to be expanding at a rate of 20-30 km/s.

Because of the effects of precession, the bright star Vega was the pole star twelve From our point of view in space the rings are actually the 'equator' of the gas cloud and we thousand years ago and will be again in are looking 'down the pole' at it (imagine looking at Earth from a space-ship thousands of miles just under 14 000 years.

above the north pole). Passing by M57, we move onto γ-Lyrae. It was thought to be another binary double star but we now know that the 'companion' star is just a star which happens to be in line of site between us and γ. Once more using Vega as our jump off point for the next star-hop (3), we go to ζ-(zeta) Lyrae

The Southern Astronomer No.70 â&#x20AC;&#x201C; July 2014

The Southern Astronomer No.70 – July 2014 Observing Notes continued

which is actually multiple star system – the brighter stars of which are easily split into their two components using a pair of binoculars. The remaining stars in the system are faint (about 11m).

FOR THE BEGINNER: Star Magnitudes

Heading from ζ eastwards (4) we come to δ-(delta) Lyrae. It is again a double star system laying an estimated 1100 light years from us. Its two stars – one blue, the other an red/orange-giant orbit each other in a period of about 88 days. Whereas δ is 5.5m the companion is much fainter at about 10m with the separation between the two bodies being very close. The binary nature of δ was discovered using spectroscopy. Our fifth star-hop in Lyrae is out to a pair of stars – ε-(epsilon) Lyrae, picture below.

Astronomers measure the brightness of stars by expressing them as magnitudes or m as it appears in The Southern Astronomer. Two magnitudes are often expressed – apparent and absolute. The apparent magnitude is the brightness of the object as seen from the Earth, the scale of magnitude of interest to amateur astronomers. The brighter an object is, the lower its magnitude. The fainter an object, the higher the figure. The scale we use today is based upon the work of British astronomer Norman Pogson who defined that a first magnitude star was 100 times brighter than a star of 6m which is at the limit of naked eye visibility. A 1m star is 2.512 times brighter than a star of 2m. Of course there are objects brighter than 1m. There are quite a few stars, plus planets and the occassional comet that are brighter so a minus sign (-) is used in front of the number to show that it is brighter. The Full Moon is -12.7m while the Sun is -26.7m. Absolute magnitude is the measure of luminosity of any star or celestial object if observed from a distance of 10 parsecs (32.6 light-years). Our own Sun has an absolute magnitude of 4.83 and would look a faint star in a dark sky of a theoretical planet 10 parsecs away. Vega on the other hand which as a bright object in our sky would still be very bright with an absolute magnitude of 0.58

Star-hop 5: Vega to epsilon Lyrae o

About 1½ northeast of Vega are two stars, ε1 and ε2. These stars are known as the Double-Double as each star has its very own easy to see companion. ε1 4.7m while the companion is 6m. They orbit each other in a period of about 1100 years and due to the angle we are looking at it, the two stars appear to be slowly closing in on each other. ε2 is a 5.1m star and its companion is 5.5m. Both ε1 and ε2 lays at a distance of 162 light years away from us; there is some doubt that they are in an orbital relationship with each other, though other take a view that they are. Of interest is that using large telescopes, complex interferometry, and spectroscopic analysis it appears that there are actually ten stars in the ε1 and ε2 group. For the amateur observer, the test of a telescope is observing ε and splitting it into its two components.

The Southern Astronomer No.70 – July 2014

Stellarium

The sky from Sussex at around 21.30 UT (22.30 BST) on July 15 Contributions – written articles (preferably word processed), photographs or letters to the editor for the August issue should be in by July 15 and sent to the editor at the contact address: editor@worthingastronomers.org.uk Detailed occultation predictions and other data in PDF format may be had by contacting the same address. (Please include exact latitude, longitude and approx height above sea level – these can be found using a service like Google Earth, for example.) If you no longer wish to subscribe to the group and receive newsletters and other information, please send an email (to the address above) with Unsubscribe in the subject line; we do not want our stuff to end up like spam littering your inbox. 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. 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.

The Southern Astronomer No.70 – July 2014

USEFUL ASTRONOMICAL RESOURCES Tools for your PC or smart phone (will run on Windows, MacOSX and Linux systems)

Stellarium – at home in a planetarium or your PC. Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just as you see with the naked eye, binoculars or a telescope. Just set your coordinates and go.

Virtual Moon Atlas - This software is the result of a collaboration between Christian Legrand, a passionate lunar observer and co-author of the guide "Discover the Moon" published in English by Cambridge University Press and Patrick Chevalley, author of the worldwide known freeware "Cartes du Ciel / Sky Charts". The authors have made it free for amateur astronomers, lunar observers and students who wish to practice selenography (the practise of scientific observations of the Moon). They hope to promote Moon observation and knowledge because "..our satellite will become one of the next human spatial exploration step."

Websites DeepSkyPedia - DeepSkyPedia is a wiki project formed to help amateur astronomers in planning their observing sessions. The goal is to make it possible to find all the information on particular object or groups of objects that you may find interesting while observing the sky. This information includes: • Sketch of an object, if available (no astrophotographs, just sketches) • Instructions and hints how to find the object • Appearance of an object in all kinds of optical instruments (or without them!)

•

Notes on nearby interesting object and other interesting facts

There are many and you may have your own favourite website to go to for software or up to date information.

Simbad – stands for the Set of Identifications, Measurements, and Bibliography for Astronomical Data is an astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de Strasbourg (CDS), France. If you want to identify or learn about a deep sky object this powerful resource will help.

Planetary Data Center – A portal to all things NASA. IRIS – a piece of software (again like the above software, free to download).

The previous list of useful and interesting astronomical resources is not a definitive list of the many online astronomy sites.

The PDC archives and distributes scientific data from NASA planetary missions, astronomical observations, and laboratory measurements.

Created by professional astronomer Christian Buil, this program allows you to capture images with a web-cam or CCD camera, process it within the same program and even enable you to analyse the images – in the case of star-fields, astrometry or even photometry (the measurement of star brightness) – an important area for variable star observers. RAW images created by digital single lens reflex (notably Canon and Nikon) can also be decoded and processed. Not a piece of software for the faint hearted or beginner but a useful and powerful tool once mastered.

Many websites have been set up by the enthusiast to disseminate information on many astronomy topics – their own telescopic work; building observatories; building telescopes; converting telescopes – the list is endless... Endless too are the many professional astronomical sites which give updates of orbiting observatories, daily solar observing, auroral displays, meteor showers – visual and radio observing; observing of the heavens using radio wavelengths.... Drop us a line or two with your favourite astronomy based websites and hopefully we can build up a list so we can publish the list here, allowing members to dip into the many varied and interesting aspects of the hobby of astronomy.