WADHURST ASTRONOMICAL SOCIETY

NEWSLETTER DECEMBER 2001

INDEX: MEETINGS, OTHER NEWS, CONTACTS,

MEETINGS

LAST MONTH

The last meeting was held on January 9, the speaker was Jerry Workman from Haringey AS and the title of the talk was "Mars Revisited". Jerry started with a brief introduction to Mars and a quick look at observations made in the past. The main part of the talk dealt with the various missions that have been sent to Mars, from the Mariner missions in the 1960's to the Viking missions in the 1970's. The whole talk was illustrated throughout by slides taken by the various probes. There are obviously a lot to choose from as the Viking missions between them took 55,000 images! Jerry looked at a number of surface features and discussed the various theories as to how they were formed. The features looked at are massive by Earth standards, for example the four huge volcanoes in the Tharsis region are all 17 miles high! Another example looked at was the Mariner valley, which is over 3000 miles long and 3 miles deep. The Viking landers also looked for evidence of life on the planet. Jerry explained not only the results, but the reasons that these results were to prove disappointing. Jerry then went into a little detail about the 1996 Martian meteorite, the statement that these contained evidence of Martian Life is bold to say the least! We were next treated to a look at the 1997 Pathfinder mission, again with some amazing slides. Mars Global surveyor was also discussed along with the famous face on Mars! A brief mention was then made of the future missions, including a possible sample return mission in the next 10 to 15 years.

The meeting then had a break for refreshments, before re-adjourning for any other business. These items are all dealt with in their separate sections below.

NEXT MONTH

The next meeting is to be held on February 13 at the usual time of 7.30 and the usual venue in Uplands. The speaker this time is our very own Ian King who will be giving a talk on the subject of Astrophotography. Bearing in mind the quality of Ian's photographs I feel sure this will be interesting to all members.

GO TO INDEX

OTHER NEWS

TREASURERS REPORT

We are awaiting the billing from Uplands College for the hire of the Drama Studio for the period October 2001 - July 2002. It is promised shortly. Meanwhile the Society's current account stands at 296.98 and the Reserve account 1522.06.

So far 32 of our estimated 55 members have paid their subs for the year. It would be encouraging if those who missed the well-attended January meeting and those who forgot to bring or send their cheques will again become fully paid up voting members. The cost is 12.50 single and 17 joint membership for the year to 31st October. All being well membership cards will be issued at the next meeting.

It is believed that some suppliers of astro equipment are inclined to offer discounts to buyers who can produce evidence of current membership of an astronomical society. Although, we have so far had no confirmation of this from any supplier

FUNDRAISING

It is hoped that we will have time to discuss some ideas concerning fundraising at the next meeting. The society has attended a number of events in Wadhurst over the past few years and has run a Tombola that has been reasonably productive. However, it is possible that we should be thinking along different lines for fundraising. Fundraising is important to the society as it keeps the cost of membership to a reasonable level. For example over the past four years we have managed to raise nearly 900, with a membership of 50 this equates to 5 per member per year. Raising subscription costs is a last resort; it would be much better to raise funds by other means. Please have a think about the subject and come along to the next meeting to join in the discussion.

SOCIETY TELESCOPE

The society telescope is now ready for loan to members! It was first available at the last meeting where a number of members looked at it with interest. For the record the telescope is an 83/4" f5.8 dobsonian reflector, with a focal length of just under 51". There are three eyepieces that come with the scope which give magnifications of 51x 72x and 204x. A book and planisphere come with the telescope, as does a logbook, which everybody is encouraged to fill out. There is a small charge of 5 per month for the loan of the telescope and also a refundable deposit of 30. If you wish to hire the telescope please contact Peter Prince, either by telephoning 01892 836284 or speaking to him at a meeting. Peter will deliver the telescope to you on the day after the meeting and it will be up to you to return it at the next meeting.

HEAVENS ABOVE

Good news from Sussex University concerning the Public observing sessions. They have now agreed that the Observatory at the Isle of Thorns can continue. Heavens Above have therefore reviewed their telescope requirements, and decided to sell the Celestron 8 inch. This is on the German Equitorial mount and a rigid tripod. In a recent issue of Astronomy Now it was listed at 1099 . It has only been used once, at our last Mencap viewing session. It is offered to members at 825. It will be displayed at our next Society. For further details please contact Duncan on 01892.852.481

WEB SITES

There is an interesting web site that is running free Monthly Astronomy lessons. The lessons started in January and will be published on the site at the beginning of each month. The lessons are only available for one month so you will have to log onto the site at least once a month. However, the January lessons are on the site for the year so you will not miss the first lessons by logging on now. The course looks suitable for beginners but also looks as though it could have some interesting lessons for more experienced members. Check it out here.

CONSTELLATION OF THE MONTH

The following is a full copy of the notes on the constellation of Orion that Sean used at the last meeting;

The constellation of Orion is one of the most recognizable asterisms in the sky. Orion, in mythological terms, is standing by the river Eridanus, and can be seen shooting at Taurus the bull with his bow and arrow. He is accompanied by his dog, Canis Major, who is busy chasing Lepus the hare.

Marking Orion's left shoulder, as seen by the naked eye, is Alpha Orionis, better known as Betelgeuse (pronounced BET-el-jooz). This Red Supergiant is the 10th brightest star in the sky, and really does deserve to be classed as a giant. The star is 310 light years away, and has a diameter of over 400 million km. This is so huge that the Earth's entire orbit around the Sun could fit inside the star! It's shear size makes it unstable and it erratically fluctuates by up to 400 diameters of the Sun. Moving diagonally through the three stars forming Orion's Belt, you will find Beta Orionis, better known as Rigel (pronounced RYE-jel). Rigel is actually brighter than Alpha Orionis and is the 7th brightest star in the sky. Rigel is a blue-white giant, 910 light years away and has an absolute luminosity of 57,000 times of the Sun.

The jewel of Orion is M42, the Orion Nebula. This wonderful emission nebula can be seen with the naked eye as the fuzzy patch around the middle 'star' of Orion's sword. The nebula is a vast gas cloud 40 light years across and glows due to the ultraviolet radiation from Theta Orionis. Theta Orionis is actually two multiple stars, Theta1 and Theta2. Theta1's four brightest stars (mag 5 to 8) form the Trapezium and can be resolved with telescopes larger than 2 inches. The trapezium stars are very young by astronomical standards, perhaps only 1 million years old.

The easternmost star of Orions belt, is Zeta Orionis, known as Alintak (pronounced al-NIGH-tak), can be used as the guide star to find the Barnard 33, better known as the Horsehead Nebula, which lies approximately half a degree due south of the star. This dark nebula looks like a horse chess piece, and can be seen in front of the brighter nebula IC434. Although this is one of the most photographed deep sky objects, its low contrast against IC434 makes it very difficult for amateurs to observe. A slightly easier target for amateur observers is NGC2024, the Flame Nebula, which lies half a degree south of the Horsehead Nebula. The 'flames' are part of the same dark nebula which forms the Horsehead, but have a much greater contrast between them and the emission nebula behind them.

The Orion, Horsehead, and the other nebulae are all part of the same gas cloud complex, known as the Orion Molecular Cloud comprising mainly of hydrogen with traces of helium, carbon, nitrogen, and oxygen. This covers almost the entire constellation and is over 100 light years wide, and over 1500 light years distant. Although this may seam a very long way away, it is actually our nearest star-forming region.

Designation

Common Name

RA (h m s)

DEC (d m s)

Mag

a Ori (Alpha Orionis)

Betelgeuse

5 55 17.1

+7 24 24

0.4 1.3

b Ori (Beta Orionis)

Rigel

5 14 38.4

-8 12 03

0.12

q1 Ori (Theta1 Orionis)

The Trapezium

5 35 22.7

-5 23 22

2

z Ori (Zeta Orionis)

Alnitak

5 40 51.2

-1 56 49

4

M42  (NGC1976)

Orion Nebula

5 35 30.3

-5 27 00

3.7

M43 (NGC1982)

de Marian Nebula

5 35 42.3

-5 16 00

6.8

IC434

Behind Horsehead Nebela

5 41 6.4

-2 24 00

8.2

B33 (Part of IC434)

Horsehead Nebula

5 41 6.4

-2 24 00

8.2

NGC2024

The Flame Nebula

5 42 0.4

-0.1 51 00

 

M78 (NGC2068)

(reflection nebula)

5 46 48.5

0 02 59

8

NGC2022

(the only planetary nebula in Orion!)

5 42 12.8

+0.9 05 01

12

A map of the constellation can be found here and further details on Orion here.

GO TO INDEX

CONTACTS

Chairman: Murray R. Barber 01892 654618 murray.barber@virgin.net

Secretary: Tim Bance 01732 832745 timbance@hotmail.com

Treasurer: Ian Reeves 01892 784255

Editor: Peter Bamblett 01732 368656 pbamblett@hotmail.com

Web site: Rob Cray rob@arcray.net

Publicity: Michael Harte 01892 783292 michael@greenman.demon.co.uk

Dir. of Obs.: Sean Tampsett 01892 667092 sean_tampsett@hotmail.com

Librarian: Joan Grace 01892 783721

Custodian of Equipment: Peter Prince 01892 836284

GO TO INDEX