WADHURST ASTRONOMICAL SOCIETY

NEWSLETTER MARCH 2001

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INDEX: MEETINGS, OTHER NEWS, ARTICLE

MEMBERS' SATISFACTION

Are you satisfied or dissatisfied with the form and content of the Societies meetings? Are the talks that have been arranged a) too advanced b) just right c) too basic? Do you like the newly introduced series of getting to know the constellations? Are there too many talks? Is there a case for additional but non-lecture type meetings?

The organisers have tried to be mind readers, but without the benefit of your opinions it is likely that the society could be going in the wrong direction. The absence of comment does not necessarily mean a satisfied membership. Questionnaires have been sent out, but have proved ineffective in the past. The committee needs your input! Please write, phone or e-mail the editor, Peter Bamblet, 01732 368656), or indeed any member of the committee (contact details below), with your comments, opinions, suggestions or recommendations.

We are affiliated to Uplands, which is a community college. The society is open to all comers irrespective of their expertise. The last thing we want to become is a stuffy all male group of technocrats; that comment comes from one of the too many male members of the committee.

MEETINGS

LAST MONTH

As I hope all members are aware, Peter Gill had to unfortunately cancel as the speaker for last months meeting. This was due to a recent illness, however the talk has been rescheduled for the meeting due to be held on the 10th October. We were however fortunate that our very own Peter Prince was able to give us his talk that had been originally planned for then. His talk was on the life and death and stars. Peter started with a brief history of the Universe starting with the big bang and going up to the formation of galaxies. The first stars that formed would have died in supernovae, and these created the elements that went on to form objects such as planets. He then went on to detail the different theories of star formation, with the emphasis on the most plausible theory that includes accretion disks. By using H-R diagrams Peter gave us some examples of the different types of star and how mass is so important to the life and death of each one. Peter also dealt with the two forms of nuclear reaction that takes place inside stars. This then lead into the final outcome for various stars including our Sun. The talk was followed by a question session in which a number of interesting points were raised including possible ends of the Universe. Thanks again to Peter for bravely stepping into the breech. Peter’s talk was followed by the regular session by Joan on the constellations. This month Joan covered Andromeda, which as stated last month borders on Pegasus. Joan has now dealt with three adjoining constellations that all have the line of zero hours right ascension running through them. Joan then also told us the mythology that links Cassiopeia, Pegasus and Andromeda

NEXT MONTH

The next meeting is due to be held on 11 April. As usual the venue is the drama studio at Uplands and the meeting starts at 7.30.The speaker is Conrad Malin-Smith, and the title of the talk is La Palma Observatory. Some members may recall that Conrad gave us a talk last June on Binary Stars. Those members that were present on that night will remember that Conrad is an excellent and extremely entertaining speaker.

COMMITTEE MEETING

A Committee Meeting was held on Thursday 29 March. The first point on the agenda was about some minor but important changes to the constitution of the society. These changes would obviously have to be authorised at this years AGM, and full details will appear in a newsletter nearer the time. It was decided that the society would have a telescope that can be loaned to members. A decision was made that this should be an 8" Dobsonian reflector and that Tim, Murray and Duncan would liase on the building of it. The anticipated cost is in the region of £300. Peter Prince has agreed to act as custodian of the telescope when it is completed and was therefore officially voted onto the committee. It was also agreed that the society would buy a planisphere and basic guide to go with the telescope The date for the annual Bar-B-Q has been arranged for Saturday 1st September, so mark it in your diaries now! Again, more details will be given nearer the time.

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OTHER NEWS

TREASURER'S REPORT

As of the middle of March, the society accounts stood at Current account £488.49 and Reserve account £1011.94. The society currently has 35 fully paid up members plus 2 students, there are however, still 7 subscriptions overdue. I would also like to remind members that by the time they receive this newsletter there are just 70 days to go before the Fete. The volunteer list is open with five names recorded on it and there are now a dozen prizes for the tombola. More volunteers are welcome as are tombola prizes.

WEB SITES

Thanks to Ian for the following list of sites. They are apparently the favourite sites of Dr Robin M Catchpole the Chief Astronomer at the Royal Observatory!

The Royal Observatory site!

Instruments & equipment.

General & scientific news from CNN.

for the very latest solar images from NASA.

the Space Telescope Science Institute.

Rob is still looking for images to add to the photo gallery on the WAS website.  If anybody has any, can they either scan them and e-mail to Rob or bring a hard copy to a meeting so that they can be scanned and used. Although astronomical images are obviously welcome, please remember that the site could also use images of society events.  Has anybody got any images taken at last year's Lunar samples evenings for instance?

FOR SALE

Hunter 4.5 Astronomy Reflector Telescope with Terrestrial Mount and Tripod. £250 ONO. Please contact Philip Child, Golds, Catts Hill, Mark Cross, CROWBOROUGH, TN6 3NH. Telephone 01892 852148 or e-mail

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DEEP SKY TECHNIQUES AND THE CORE OF THE COMA/VIRGO CLUSTER

Here is the second part of the article by Murray Barber, this part is on observing the Core of the Coma/Virgo Galaxy Cluster

Let us now consider the wonderful abundance of galaxies in the Coma-Virgo cluster. I'm going to assume that the reader is equipped with a copy of the Uranometria and has the same degree of difficulty that I have with light pollution. The following notes have been made using an ordinary 10" Newtonian reflector, from an ordinary UK garden and not from the top of some mountain in California. I have not used any filters due to the fact that they have limited value in most cases for galaxy observations. I will give the Messier objects only scant regard because they are fairly straightforward objects to locate. Don't miss them, even though you may not feel as challenged, they are splendid objects. The main advice I would give is familiarisation of the constellations which is a great help to finding the treasures in them.

Before heading off to the very core of the Coma/Virgo cluster, lets start from one of the showpiece objects in Coma Berenices, the so called Needle Galaxy, NGC 4565.To find this splendid thin edge on shape, first find the star 17-Al in Coma Berenices (Urano map 149).The view through a low power eyepiece is two stars, in which one of them is double. Move the telescope nearly 2 degrees to the east. Suddenly, a splendid 9.5 mag ribbon of light will enter the FOV with a distinct central bulge. Notice also a star very close by to the central regions, which shows up very well in photographs. Can you see a dark dust lane running through the centre of the galaxy? Now, don't be afraid to increase the magnification even though this may feel like a contradiction to see a faint object. The effect of increasing the magnification not only makes the image bigger but also increases the contrast. Incidentally, as you move the telescope from 17-Al only 1/2 degree to the east you should notice the 9.8 mag galaxy NGC 4494 that is adjacent to a 9th mag star.4494 appears as a small fuzzy dot.

Again, returning to 4565, travel north (towards the North Pole Star) by 2 degrees toward the 9.8 mag galaxy NGC 4559.I have described this object as a broad long ellipse with 3 faint stars superimposed upon it. From this position, move the telescope to the west by 2 1/4 degrees and locate Coma Berenices 15. This is the top star in this constellation, its general shape reminds me of the Eiffel Tower! From here continue to move west about 2 degrees to find NGC 4251.Here we have an observer’s enigma, for this galaxy is shining at mag 11.6 and yet in spite of this and its small size it’s easy to find! It looks like an out of focus star with a bright core. Again, use high mags to examine this E7 type object.

By now, with the appetite fully whetted, lets proceed into the ‘Bowl of Virgo’. This area is so rich in galaxies that Edwin Hubble called it the ‘Realm of the Galaxies’. The cluster members numbering some 3,000 are now thought to be about 40 million light years away. This particular grouping appears to be the core of an even larger group, the ‘Virgo Supercluster’.

To proceed to the core we have to start from the rim of Virgo's Bowl, because in this area abundant in galaxies there are very few stars to guide us (Urano map 194).First with a low power, locate the star 47 Virgo (epsilon) and move the telescope to the west by just over two degrees. Entering the FOV are two galaxies, NGC 4762, an edge on spiral (looks a bit like a small version of the Needle Galaxy) and the fainter NGC 4754. The latter object appears as a roundish blob and contrasts strongly in appearance with 4762. I think this is one of the most wonderful galaxy pairing in the spring skies! From here move north by 3/4 of a degree and west by 1 1/2 degrees to the 6th mag double star Virgo 34.Very carefully move the telescope north by 1 1/4 degrees and continue to move west by 2 1/2 degrees. Your eyes should be rewarded by the appearance of M90.Although very diffuse and faint it is a large object. If you have missed M90, try again remembering to give the telescope a little shake and to use averted vision. We have nearly arrived at the core!

Move the telescope south by a mere 1/4-degree and finally continue moving west by 2 1/4 degrees (Urano map 193).We have arrived at the very core of the Coma/Virgo cluster! What can we see? In the FOV of a low power eyepiece two M's are immediately apparent, the large and bright elliptical galaxies M86 and M84.M84 is to the west and is slightly smaller and slightly fainter than M86.Again with the low power you should make out two faintly glowing patches a little to the east of M86 and about the same distance that M86 is from M84.Now increase your power to something like x80 to xl00 and have a good look. One of these two small objects is distinctly elliptical in form whilst the other is a round blob with a central brightening. They are the interactive galaxies NGC 4438 and NGC 4435 respectfully. In photographs 4438 is tidally disturbed by the presence of 4435.

By now finding galaxies is becoming a bit like 'falling off a log', so lets try to find other members of the core that are a little more challenging. Very carefully, still using the power from examining the interactive galaxies, return to M86 and carefully gaze slightly to the north. With luck the edge on spiral NGC 4402 will appear like a ghostly phantom of light shining at magnitude 11.2. Move the telescope into a position between M86 and M84.From here move the telescope south by about 1/5th of a degree and look very carefully. An edge on spiral galaxy, NGC 4388 again at 11.2 magnitude should become apparent. This will be a steady image and its elongated form should be obvious. Now, relax, breathe normally and don't try to screw your eye into the eyepiece. Look between 4388 and the centre line between M86 and M84.Occasionally popping into view is the tiny 1.9' x 1.1' elliptical galaxy NGC 4387 shining at only 12th magnitude. Be patient, it will come with care. Centered on 4387 and contained within a degree field, ten galaxies reside, all obtainable with a 10" telescope.

All of this is of course only the 'proverbial tip of the iceberg'. All the objects listed in the NGC can be seen with a 12" telescope and more: over 20,000 are within the reach of the dark sky observer. Of course the number of deep sky objects observable with an amateur telescope equipped with a CCD camera is beyond belief! A friend of mine in Dorset who has a CCD equipped 20 inch told me that in a 50-second integration he is imaging down to magnitude 19!

I hope that you, like myself will discover the same fantastic sights that I have been able to see and more. Remember the real thrill is to contemplate the full significance of these tiny glowing pools of fossil light, the photons of which set out on the long journey to reach the Earth perhaps 38 million year before humanoids appeared!

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