MIRA 16
March 1987


AURIGA CLUSTERS



11th November, 1986. 21.00 - 22.15 UT.
Sky clear and transparent but hampered by a bright moon. 8½" Spec.
All views at x85     Field of view - 29'
Remarks: All three clusters in same vicinity of the sky and ideal for small telescopes or binoculars. M37 gives the most pleasing view with larger scopes.

Observer B Merrikin.

In addition to the three open star clusters illustrated which can easily be seen in binoculars, fine star fields can be seen whilst generally sweeping as the constellation lies within the Milky Way. Also refer to Mira 12, page 3 for details on double stars.


Summary of Astronomy Week at Southam
By Angela Turner

Although what can and was considered an utterly grotty start to the week with only three personages and a dog (!) turning up on our beautifully clear kick off night, the tide soon changed its course however and it wasn't long before we had the pleasure of having a queue behind our respected telescopes on the other clear nights.
Strictly speaking we may consider that we were exceptionally lucky weather wise and over the course of the week experienced no less-than three superbly clear nights where atmospheric clarity was also superb.   In view of the generous weather we therefore decided to extend the astronomy week over to Friday, Oct 17th to include the eclipse of the moon.  This proved to be a great success with an exceptionally large proportion of the public turning out to observe what was a very impressive eclipse; moreover we were fairly lucky as skies remained clear until! almost totality when the clouds set in and of course refused to budge.
Saturday, Oct 18th as was predicted gave us the greatest bulk of personages who cane to view such delights as Jupiter and the moon; Saturday being the one night where we knew we would be desperately short of telescopes (tempers too I night add!).  However, people did remain patient and after eight-o'clock we had what I can only call a good show of varied scopes.  Saturday in my opinion revealed the moon at its very best, being one day past first quarter there was an abundance of relief features to astonish the public.  It really is a very fine feeling when people look up in utter disbelief at what they have just seen, knowing that it is you who has just helped to educate them to the wonders of astronomy.  In all there wasn't one single person who complained at what they'd seen and everyone who came was more than impressed, and I'm very glad to say that as a direct result of our astronomy week we will have the pleasure of having some new members.
Besides generally having a good time our combined efforts managed to raise a sum of £26.70 for handicapped children and £11.35 for the society.   The difference in the monies being, the eclipse night of which we asked solely for donations to go to the charity for handicapped children.
My heartfelt thanks to all those who supported the society during the course of the week and how about it again next year?

Above is a comprehensive summary of the observing week at Southam which satisfied it's objectives which were firstly, for the general public to gain some idea of what can be seen through moderate telescopes of various celestial objects, second,to rise money for charity and thirdly, help to promote the Coventry and Warwickshire Astronomical Society.
Below is a letter of thanks and appreciation from the president of the Children Handicap Aid Fund to Angela in particular, who single handed organised the event with very little co-operation from the society.
Ed. VC


30th November 1986.
Dear Angela
I hope that you will forgive me for taking so long to thank you and all of your friends from the Coventry Astromany Society for the very kind Donation of almost £27 to our fund, I can assure you all that the money that you all put so much time and effort into will be put to a very good use, and appreciated, by children from all over the Warwickshire area, as the project for 1987/88 is to help not only the Handicapped, children, but to help any child in the area that might have a accident that requires hospital treatment, and that project is to help raise the funds for a Children only, Casualty Wing at Warwick Hospital.
I think you will all agree that this project although not yet official is a very worthy project, in fact it ip so worthy that many of the nursing staff are holding a meeting next Wednesday, and have asked me to attend to discuss ways of raising funds by way of a joint effort with C.H.A.F. and my committee and myself have agreed to give this venture our full support, and with the help of people like yourself and your friends in the Society I know that we will succeed.
Once again, on behalf of myself and the C.H.A.F. committee, I thank you all.

Yours Sincerly
Ray Sidgwick. President C.H.A.F.






Airborne Observing the Hard Way
By Mike Frost

We stood at the British Airways check in desk at Glasgow airport.
"Smoking or non-smoking?" the clerk behind the booking computer asked.
"Non-smoking please. And could we have window seats facing east please?"
He looked puzzled. "Facing east? Are you praying to Mecca or something?"
"No" I said patiently "I'd like to watch the eclipse of the Moon - it's happening tonight"
"Oh, I see "he laughed "I've never heard that one before let's see, the east facing side - that'll be on the left looking down the plane…"
Together with a fellow engineer, Mahendra I had spent the previous three days in Motherwell at the Dalzell steel mill, which is part of the British Steel Corporation Ravenscraig complex.  We were installing a computer link for G.E.C. and to everyone's astonishment (mine included) the link worked almost straight away and we had completed commissioning on time.  This was a relief, as I wanted to return to Rugby for the weekend.  Additionally the weather over Scotland had worsened during the course of my final day, and I guessed that my one chance of observing the lunar eclipse of October 17th. was from above the cloud layer.
However, the weather seemed determined to defeat my observing plans, as our departure time was delayed, I sat impatiently watching the telly in the departure lounge-there was no way I could delay the eclipse, and unless British Airways got a move on we would miss pre-totality.
When departure time was announced, I was at the gate in double quick time.  However, as I produced my ticket, I realised that my instructions had not been followed to the letter.  Sure enough, we were on the left hand side of the plane, but instead of being allocated two window seats, we sat side by side - and my place wasn't by the window.
Now, you'd have thought there'd be no problem - we worked together as a team for three days.  But Mahendra, grinning mischievously, was first on the plane and into his seat by the window.
"Are you going to let me watch the eclipse?" I asked.
"No" he said, and pulled down the window blind.
"Ladies and gentlemen, this is your captain speaking we apologise for the delay in departure time which was due to our late arrival following bad weather in Munich.  We will be flying over Manchester tonight, and those of you on the eastern side of the plane will be able to watch the eclipse of the Moon.  Thank you..."
Some hope, I had at least persuaded Mahendra to raise the blind, but he refused to shift from his seat by the window.  "Oh look, there's the Moon" he cried I strained to see it, but it was just at the edge of my line of sight.  Worse, we had not quite cleared the clouds and ever so often the full moon, now with a substantial bite taken out of it, would disappear behind a veil of mist.
Frustrated in my attempts to gain a clear view, I decided to try a different approach, I called the stewardess.
"Excuse me, would it be possible for me to go into the cabin to watch the eclipse,?"
She gave me a British Airways who-does-this-jerk-think-he-is? smile and answered me with impeccable logic, "You're already in the cabin.  Do you mean the cockpit?"
Can I help it if I don't know the difference?
"Yes, I mean the cockpit ..I believe the pilot has quite a good view from the front."
"I'm afraid that isn't possible tonight, she said sweetly, the free seat in the cockpit is already taken - airline staff I'm afraid."
I was tempted to ask if he wanted to swap seats but my courage had deserted me.
Instead I return to watching the Moon, which was now in the centre of the window, with the eclipse approaching totality.  Although the clouds were no longer present, observation was still difficult, primarily because of the illumination inside the cabin, and secondarily from the navigation lights outside.  Even if I asked them nicely , I doubted that the pilot would switch off either set of lights.
For these reasons, the onset of totality was very difficult to judge.  Indeed, we wondered perhaps the pilot might have taken the plane into and then (briefly) back out of the totality shadow.  I would guess not but since planes have flown for considerable periods in the shadow, of a total solar eclipse.  I suppose our North/South flight could have taken a small detour to bob in and out of totality (so the pilot could win a bet perhaps?)
Most likely our view of events was not good enough to judge whether or not the Earth's shadow had covered the Moon completely.
You will have gathered that observing conditions were far from perfect, and to be honest the most spectacular sight on view was of Manchester (my home city) below us.
After seeing the coppery colour of the Moon in the January 1982 eclipse I was disappointed not to see any distinct hue this time round , but I gather that this eclipse was altogether darker and my problem may not solely have been one of contrast against a bright foreground.
For me, the latter portion of the flight I had lost patience with Mahendra and leaned straight across him, ignoring his complaints, to-take the view in.
Eventually the plane dropped back into the cloud and began the decent to Birmingham airport where the cloud was more or less complete.
I don't recommend British Airways flights as an ideal site for astronomical observations goodness knows how anyone ever managed to observe Comet Halley from Concorde.
But if you ever do get to fly during a eclipse of the Moon, make very sure that you've booked a window seat.






Discoveries by Exosat


The E.S.A. X-ray satellite Exosat has detected two stars in the constellation of Sagittarius called X1820-30 (named after it's celestial co-ordinates) which form a bright X-ray source 20,000 light years away.  The system features a dying white dwarf star trapped in the gravitional grip of a neutron star, the X-rays are produced by gas falling from the white dwarf star onto the neutron with a velocity of one third the speed of light.  This releases an enormous amount of energy (10,000 times that of the Sun) from the neutron star - which is only 20km in diameter.
What Exosat discovered was a 11 minute low level pulsation in the x-ray from X1820-30 due to the orbital period of the white dwarf which is only three times bigger than the Earth and made of pure helium circling the neutron star; these two stars would easily fit between the Earth and Moon and yet the total mass would of the system be one and a half times that of the Sun.

Exosat was launched by a Delta rocket in May 1983 and ceased operation in April last year.






Features to be Observed in and around Mare Crisium
by Geoff Johnson

To the new observer, learning the Moon by following the terminator; an exciting new world lies before him, waiting to be explored.  Starting shortly after New Moon he will already have noted and hopefully made sketches of the great chain of ringed plains near the south-east (l.A.U.) limb, visible to advantage on the thin crescent Moon.  As the terminator progresses westward, when the Moon is 4 - 5 days old, further regions of interest come into view.  In the north-east quadrant the Mare Crisium can be seen.  Who bettor to describe it than HP Wilkins and Patrick Moore in their book "The Moon".
Mare Crisium; the Sea of Crises.  One of the smaller of the lunar 'seas' but probably the most interesting and the most beautiful in the telescope.  In fact, the Mare presents a charming picture unique among the lunar formations.  It is visible to the naked eye as a small dark oval spot. Although it is elliptical in shape with the major axle from east to west, it appears,owing to fore-shortening, as a strongly oval spot with the greatest extension from N to S.



Part of Wilkins & Moore's map of the Moon showing Mare Crisium

Its dark grey surface, slightly tinged with green, especially at full, is very deeply depressed in comparison with the bright mountainous surface outside.  The area is 66,000 sq. miles, or 1/94th of the entire visible surface.  From the southeast border a strongly marked promontory, the Cape Agarum, intrude a upon the surface.  The highest peak in this region rises 11,000 feet.  East of Agarum is the deep bay extending to the north-west of Condorcet.  From Agarum a long ridge runs concentric with the somewhat low and indefinite eastern border of the Mare as far as the ring Cooke.  Midway along its course this ridge passes a little to the west of some isolated hills which in their turn lie a little to the west of a mountain mass on the Mare. The eastern, border from this point is well-marked with several high peaks and mountain masses.  Under a high light a long and valley like depression, the Mare Anguis, line's the outer border to Eimmart, conspicuous as a dark contorted streak.
On the north the border consists of a gently sloping, broad plateau, divided by wide passes, the whole sloping upwards to the high ground south and south—west of Cleomedes.  From this point the western border is well marked, with peaks rising over 13,000 feet, but one peak to the south-west of Picard rises 15,600 feet.
The west border is divided by narrow valleys, to a peak east of which, on the open plain are several small but in part, lofty mountains.  Midway along the west border is a narrow pass leading into a ruined ring, with a small central hill on which is a summit craterlet.  The southern promontory of this ring is called the Prom Lavinium and the northern Cape Olivium.  From the former the border is lofty and continuous towards the south, with some craters on the crest and ends an the far south in a bold headland....
The largest ringed plain on the Mare is Picard, with bright walls, rising 5,000 feet above the depressed floor on which is a small central hill.  In contact with the south wall of this 21 mile crater is a minute craterlet.  About 40 miles to the west is a large but very shallow depression with a central craterlet... the whole appearing as a white spot.  Invisible at sunrise, it makes its appearance when the solar altitude reaches 15° and increases in size until just before full after which it decreases again.  It also sometimes decreases in size during the progress of a lunar eclipse.  Thornton (l955, 18in refl.) has found that this feature is actually a low dome crowned by a minute deep pit, so that it bears a striking resemblance to the modem Linne.  West of Picard is a long ridge, very variable in altitude and concentric with the border, curving east and ending in a large very shallow spoon shaped ring, evidently a partly buried crater ring. Beyond this ridge and west of Picard is an obscure ring, Yerkes, its eastern wall having disappeared.  On the interior is a low central mound...
Next tine you have an opportunity to observe the 4 - 5 day old Moon, see how many of the features described above you can identify.










Sun Rise Over Gassendi



Date          30th April 1985

Time         20.40 to 21.00 UT.

Instrument 6in. Reflector x120 & 180

Seeing       Fair

Observer    Vaughan Cooper


Gassendi


On the northern boarder of Mare Humborum lies Gassendi a 55 mile diameter crater with 9, 000ft walls on it's western side, the south walls have been reduced to mere banks.  The interior contains a central mountain of 4,000ft, remains of an inner ring craterlets, ridges and a system of clefts some of which are well represented in Mr. Marriott excellent drawing.

To the immediate north of Gassendi lies Gassendi A (named Clarkson on some former.maps) and it will be noticed that this is a classical example of the smaller crater breaking Into the larger.