SUBSCRIPTIONS FOR 2011

        We have now entered the Society’s new session, and again, the subscriptions remain the same as in recent years.  Membership for the year is still £15.00 and £20 for two members within the same family at the same address.  Children and students are free and always welcome.

        Subscriptions can be made at the meetings, preferably by cheque payable to “Wadhurst Astronomical Society” or can be posted to our Treasurer, Michael Wyles at:
31 Rowan Tree Road, Tunbridge Wells, Kent TN2  5PZ

        Visitors are asked for a £2 donation to any meeting to cover costs.

MEETINGS

DATES OF THIS YEAR’S WEDNESDAY MEETINGS

16th February
16th March
20th April
18th May
15th June
20th July

No August meeting
21st September
19th October
16th November
14th December 2nd Wednesday

JANUARY MEETING

Annual General Meeting

        The Society’s chairman, John Vale-Taylor opened the Annual General Meeting by reviewing the past year’s events and looked towards another successful year of the society.

        Phil Berry, the Secretary thanked members who had given talks during the past year and announced that yet another member’s talk was in the pipe-line.  A further talk he is trying to arrange is on DSLR cameras and their use in astronomy and the use of Registrax to process images.

        Mike Wyles presented the accounts which look healthy, the only outgoing increase being the hire of the hall.  He said he was greatly helped by the number of talks given by Society members.  During the past year we gave a donation of £15 to the Campaign for Dark Skies in lieu of payment to one guest speaker.

        The Society’s Current Account stands at £303.15 and the Bank Reserve at £1170.48 which has enabled him to keep our subscriptions at the same level as in previous years.

        The Newsletter Editor enquired if members using the Internet were able to download the Society’s monthly Newsletter.  Everyone at the meeting affirmed that they did.  He also asked if anyone had suggestions for items to be included in future Newsletters and to please let him know if there were.

        Finally John Vale-Taylor told the meeting that it was proposed to hold more of the Angus Meetings where technical ideas and problems can be discussed and possible solutions offered and to which any member is welcome.  More details appear later in this Newsletter.

        Brian Mills, our Director of Observations said that he was proposing to alternate his short talks each month between constellation recognition and astronomical definitions through the alphabet.  He also mentioned that it might be interesting to hold occasional observing sessions.

        That concluded the AGM and was followed by tonight’s member speaker.

Ancient Astronomy on the Isles of Scilly

Talk by Bob Seaney

        In 2009 Bob talked to us about a number of megalithic sites around the British Isles and how Stone Age man had used them to determine astronomical events such as the longest day of the year and predicting eclipses, making those “ancient astronomers” very powerful people.

        This time Bob talked about discoveries made specifically on the Scilly Isles and of work he himself has done on lost stone circles and suggesting their use as aids to astronomical predictions.

        To set the scene, we looked at the land area around north west Europe about 10,000 years ago.  The English Channel didn’t exist, allowing peoples linked to the Balkan Refuge to cross into what is now southern Britain about 8,000 years ago.

        Around 7,000 years ago the outline of the British Isles began to be recognisable although still joined to the Continent.  Then about 5,000 years ago the channel started to fill separating the British Isles, although Bob said that even today the population still reflects some of that flow from Iberia .

        We looked at maps to see how the Scilly Isles began to appear four to five thousand years ago and so progressively emerged to be as they appear today and revealed in some modern aerial photographs.

        Bob had already done some work on standing stones on St. Mary’s, and using data derived from “Red Shift”, the computer programme had been able to predict and take photographs of sunset and sunrise from significant sites at various important times of the year such as the equinoxes.  He also showed photographs of the sun setting over certain features on some of the sacred islands such as Samson and Brhyer.

        One picture showed the sunrise at Peninnis Head on St. Mary’s taken every five minutes showing its course across the sky and another was taken from the long stone at Innisidgen of sunrise over the Eastern Isles together with various sunrises and sunsets viewed from standing stones.

        On a museum wall Bob had found an Ordnance Survey map of 1890 that showed one stone circle marked on it which would, at the present day be close to, or under, one of the airport runways on St. Mary’s.

        Looking into the history of the airfield runway, Bob thought it worth going to see for himself if there was any evidence of the circle’s existence.  He now thinks this could have been a chambered cairn although in ancient times it could still have been used to determined significant astronomical events.

        Some time later, Bob returned to the island and came upon a book written by William Borlase published in 1756 telling of a visit to the Scilly Isles he had made in 1744 when he discovered a huge stone circle or remains of a Druid temple.

        Paul Ashbee published a book in 1973 called “Ancient Scilly” in which he lists most of the archaeological discoveries made on the islands and includes many interesting alignments.

        From this evidence and experiences from his previous visits, Bob returned to the airfield and this time discovered stones off to the east which he thought perhaps had been previously overgrown and were now visible due to the clearance of land ready for the introduction of grazing animals.

        Within 15 minutes of arriving he had identified all the major stones of a circle although some of the standing stones had been removed possibly for gate posts leaving depressions where they would have been.  It was possible to see this area using Google Earth, the satellite imaging Internet site.

        He worked out alignments from the central focus and using notches in some prominent rocks.  One photograph he had taken showed the Summer Solstice at 0424 in the morning with the sun rising from the centre of one of these notches.

        Finally, Bob said he was curious to know where a 30 foot high standing stone was on Peninnis Head that had been mentioned.  During investigation on his very last day he did discover a large stone close to the light-house but it was lying down.  Why would it have been there?

        He has done quite a bit of sea navigation and his curiosity lead him to look for another standing stone on the island of Gugh and now believes that by lining up the stone of Peninnis Head due north and the stone on Gugh due west, the Druids would have found themselves right in the centre of the deep safe channel between the islands and so they could have been a navigational aid.

        During questions following the talk Bob was asked what purpose the circles might have served and he believes that the predictions would have been used in rituals, with some of the circles being as old as 5,000 years BC.

FEBRUARY  MEETING

        Wednesday 16th February 2011 – This month, member Jan Drozd updates us with a further talk about the environment from an astronomical perspective in his presentation; “Life, the Earth and the Universe”.

        Meetings begin at 1930 although members are invited to arrive anytime after 1900 as this is a good time to exchange ideas and discuss problems and relax before the meeting.

        The venue as always is held in the Upper Room of the Methodist Church at the east end of Wadhurst Lower High Street, opposite the entrance to Uplands College.  (For those with SatNav – the post code is TN5  6AT)

FUTURE  MEETINGS

        Wednesday 16th March 2011 The speaker this evening will be Robin Durant FRSA, the chairman of Adur Astronomical Society,  new society covering Hove and Brighton.  Robin’s talk is called “DSLR Astro-photography”

OTHER NOTES AND INFORMATION

THE ANGUS GROUP

Practical Astronomy Group

        At the AGM we talked about the “Angus” group that was formed (although it hasn’t met recently) a couple of years ago to provide a forum where we could discuss practical construction problems for those building telescopes, observatories or indeed anything astronomical. Sadly Angus MacDonald, whose idea the group was, passed away last year. His own brilliantly conceived project had been the addition of a large flat mirror mounted at 45º in front of his reflector to aid observing for the less mobile. 

        It was suggested at the recent Committee meeting that the group ought to continue, but that we could perhaps alter its remit to include anything that was vaguely practical in Astronomy. This could include Astro-photography with a DSLR or a cheap webcam, using processing software such as “Registax” or carrying out observations. These could be, for instance, the timing of lunar occultations or conducting meteor watches - both of these being of practical use as the results are valuable when reported to the correct organisations. In fact anything practical that can’t be done at the regular Wednesday meetings could be included. Some of the sessions would be for “brainstorming” where we could pool ideas about a particular topic whilst others might be able to call on the expertise of one of our members who has knowledge of a particular item of interest.

        If you are interested could you please contact Brian Mills so that we can gauge what interest there is?  I would stress that you need no prior knowledge at all to take part.

Brian Mills

DARK SKY SURVEY

Star Count

        As happened previously the Campaign for Dark Skies (CfDS) and the Campaign to Protect Rural England (CPRE) are organising a “star count” to try and gauge how much light pollution affects our view of the night sky. In the week from Monday 31st January until Sunday 6th February (inclusive) they want as many people as possible to count the number of stars in the area of the sky bounded by the four “corner” stars of Orion. See the map below.

        All you need to do is go out one evening after 1900 when the sky is clear and free from mist and haze and get yourself into a position that is out of the direct line of sight of any street lights. Allow your eyes to become dark adapted and locate the constellation of Orion - it is due south around 2100 so if you go out earlier it will be closer to the south east. All you need to do then is to count the stars within the rectangular area bounded by the four bright corner stars although you should NOT count the corner stars themselves.

Once you have done your count go online to:http://www.surveymonkey.com/s/star-count-2011and fill in the very brief questionnaire.

EUROPEAN ASTRO-FEST

        This year’s European AstroFest takes place on Friday and Saturday the 4th and 5th of February and as usual is held at the Kensington Conference and Events Centre, just across the road from the London Underground Kensington High Street station in Horton Street.   The doors open at 0900 each day and closes at 1800.

        There are many confirmed exhibitors including Ian King Imaging.  There are also four conference sessions, one each morning and one each afternoon.  Details can be found in the January issue of Astronomy Now and also on their website at: www.astronomynow.com/astrofest

SKY NOTES FOR FEBRUARY

Planets

Mercury suffers a superior conjunction on the 25th and so will not be suitably placed for observation until next month.

Venus is still a brilliant morning object (at magnitude -4.2) in the south east and easily visible at 07.00 although it is now drawing closer to the Sun. It spends all of this month in Sagittarius, close to the “Teapot” asterism.

Mars will be in conjunction with the Sun on the 4th of this month and so is not visible to us.

Jupiter is still visible in the evening skies on the Cetus/Pisces borders at magnitude -2.2. However by the end of the month it will set at 20.00 which is just over two hours after the Sun, as it heads towards an April conjunction.

Saturn is in Virgo (in fact it spends all year there) and is moving retrograde at magnitude +0.5. It rises at 23.00 at the start of the month but by the end of the month this has become 20.45. The rings are opening out a little as seen from Earth but by the time of opposition in April they will have closed up again slightly.

 

Lunar Occultations

        In the table below I’ve only listed events for stars down to magnitude 7.0 that occur before midnight although there are others that are either of fainter stars or occur in the early hours.

DD = disappearance at the dark limb whilst RD = reappearance at the dark limb. Times are in GMT. The event on the 14th could be interesting if the sky is clear and fairly transparent. At 14.02 the Sun will still be 22º up in the south west and Mu Geminorum (real name Tejat Posterior) will be just 11º above the north eastern horizon when it disappears behind the dark limb of the Moon. See the diagram below that shows the position of the star relative to the dark portion of the Moon.

Feb

Time

Star

Mag.

Ph

PA °

7th

17.57

45 Piscium

6.8

DD

97

8th

19.03

SAO 92310

6.9

DD

99

10th

18.12

SAO 93105

7.0

DD

114

11th

23.45

SAO 76250

6.1

DD

78

12th

18.50

SAO 76670

6.0

DD

101

13th

22.57

SAO 77413

6.6

DD

91

13th

23.41

SAO 77450

6.2

DD

105

14th

14.02

Mu Geminorum

2.9

DD

46

14th

21.42

SAO 78586

6.1

DD

79

19th

23.54

87 Leonis

4.8

RD

289

Phases of the Moon for February

New

First ¼

Full

Last ¼

3rd

11th

18th

24th

ISS

        Below are details of passes of the ISS as seen from Wadhurst that are around magnitude -3.0 or brighter. The details of all passes including those visible from other areas can be found at: www.heavens-above.com

        Please remember that the times shown below are for when the ISS is at it’s maximum elevation, so you should go and look a few minutes before these times. Times are in GMT.

Feb.

Mag

Time

Alt°

Az.

23rd

-2.9

19.05

39

SSE

24th

-3.1

19.31

56

SW

25th

-3.0

18.23

42

SSE

26th

-3.7

18.49

78

SSE

27th

-3.6

19.16

78

N

28th

-3.6

18.07

82

SSE

28th

-3.0

19.42

57

WNW

Iridium Flares

        The flares that I’ve listed are brighter than magnitude -3 although there are a lot more that are fainter or occur after midnight. If you wish to see a complete list, or obtain timings for somewhere other than Wadhurst, go to: www.heavens-above.com

        Remember that when one of these events is due it is sometimes possible to see the satellite in advance of the “flare”, although of course it will be much fainter at that time.  Times are in GMT.

Feb.

Time

Mag

Alt°

Az.

3rd

17.16

-3

29

SSW

3rd

18.43

-4

42

SSE

12th

17.41

-5

14

W

12th

18.06

-3

43

S

15th

17.53

-8

43

S

16th

17.51

-4

43

S

16th

19.27

-8

45

SE

17th

17.45

-4

43

S

17th

19.21

-4

46

SE

26th

18.44

-8

52

SSE

The Night Sky in February (Written for 2200 hrs mid month)

In the north the bright stars of the Summer Triangle are just clipping the horizon with the Plough to the east and Cassiopeia to the west of the pole. In the east Leo is fully up whilst Boötes, Corona Borealis and Virgo are just rising. Looking to the south the meridian is dominated by Gemini and the hunting dogs Canis Major and Minor, whilst Orion is still well placed though it has passed its best. To the west Pegasus and Andromeda are setting, although Auriga and Perseus are still reasonably well placed. The sword handle in Perseus is well worth a look with binoculars to see the double cluster.

Brian Mills

DEFINITIONS OF TERMS USED IN ASTRONOMY

The Bayer System

        The Greek alphabet has been in use since around 9BC and consists of 24 letters that have since gained widespread use in science and mathematics as well as being used to classify the apparent luminance of stars in a given constellation, starting with the first letter Alpha (α) for the brightest. The remaining stars are allocated letters in descending order of brightness so that Beta (β) is the second brightest, Gamma (ɣ) the third and so on. The Greek letter is followed by the genitive version of the constellation name so that Sirius, the brightest star in Canis Major, is more formally referred to as Alpha Canis Majoris whilst Vega in Lyra becomes Alpha Lyrae.

The Antoniadi Scale

        This is the method used by astronomers to record the quality of seeing, and uses roman numerals from I (one) for perfect conditions to V (five) for very poor.

I    =   Perfect seeing, without a quiver.

I I  =  Slight quivering of the image with moments of clam lasting several seconds.

I I I = Moderate seeing with larger air tremors that blur the image.

I V = Poor seeing, constant troublesome undulations of the image.

V   =  Very bad seeing, hardly stable enough to allow a rough sketch to be made.

        “Seeing” refers to how much an image moves, blurs and twinkles due to turbulence in the Earth’s atmosphere which causes its refractive index to change. The amount of blurring that causes a point source of light (a star) to become a disc (or blob for want of a better term) is measured as the “seeing disc diameter”. On top of a mountain this may be as low as 4/10ths of an arc second although much larger at sea level. Telescopes are often capable of greater resolution than it is generally possible to achieve simply because of atmospheric limitations.

Brian Mills

NASA’S SPACE PLACE

 Planets in Strange Places

By Trudy E. Bell

        Red star, blue star, big star, small star—planets may form around virtually any type or size of star throughout the universe, not just around mid-sized middle-aged yellow stars like the Sun. That’s the surprising implication of two discoveries in 2006 from the 0.85-meter-diameter Spitzer Space Telescope, which is exploring the universe from orbit at infrared (heat) wavelengths blocked by the Earth’s atmosphere.

        At one extreme are two blazing, blue “hypergiant” stars 180,000 light-years away in the Large Magellanic Cloud, one of the two companion galaxies to our Milky Way. The stars, called R 66 and R 126, are respectively 30 and 70 times the mass of the Sun, “about as massive as stars can get,” said Joel Kastner, professor of imaging science at the Rochester Institute of Technology in New York. R 126 is so luminous that if it were placed 10 parsecs (32.6 light-years) away—a distance at which the Sun would be one of the dimmest stars visible in the sky—the hypergiant would be as bright as the full moon, “definitely a daytime object,” Kastner remarked.

        Such hot stars have fierce solar winds, so Kastner and his team are mystified why any dust in the neighbourhood hasn’t long since been blown away. But there it is: an unmistakable spectral signature that both hypergiants are surrounded by mammoth disks of what might be planet-forming dust and even sand.

        At the other extreme is a tiny brown dwarf star called Cha 110913-773444, relatively nearby (500 light-years) in the Milky Way. One of the smallest brown dwarfs known, it has less than 1 percent the mass of the Sun. It’s not even massive enough to kindle thermonuclear reactions for fusing hydrogen into helium. Yet this miniature “failed star,” as brown dwarfs are often called, is also surrounded by a flat disk of dust that may eventually clump into planets. (This brown dwarf discovery was made by a group led by Kevin Luhman of Pennsylvania State University.)

        Although actual planets have not been detected (in part because of the stars’ great distances), the spectra of the hypergiants show that their dust is composed of forsterite, olivine, aromatic hydrocarbons, and other geological substances found on Earth.

        These newfound disks represent “extremes of the environments in which planets might form,” Kastner said. “Not what you’d expect if you think our solar system is the rule.”

Hypergiants and dwarfs?  The Milky Way could be crowded with worlds circling every kind of star imaginable—very strange, indeed.

        Keep up with the latest findings from the Spitzer at www.spitzer.caltech.edu.  Kids and their grownup friends can enjoy beautiful images from Spitzer while playing Spitzer Concentration at The Space Place: spaceplace.nasa.gov/en/kids/spitzer/concentration

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

hypergiants_rendering_med

Caption:

Artist’s rendering compares size of a hypothetical hypergiant star and its surrounding dusty disk to that of our solar system.

CONTACTS

Chairman     John Vale-Taylor                                                                                  pjvalet1@btinternet.com

Secretary & Events                 Phil Berry             01892 783544                               phil.berry@tiscali.co.uk

Treasurer            Mike Wyles                          01892 542863                                    mike31@madasafish.com

Editor            Geoff Rathbone                         01959 524727                                       geoff@rathbone007.fsnet.co.uk

Director of Observations       Brian Mills    01732 832691                                        Brian@wkrcc.co.uk

Wadhurst Astronomical Society website:                                                             www.wadhurst.info/was/

SAGAS web-site                        www.sagasonline.org.uk

Any material for inclusion in the March 2011 Newsletter should be with the Editor by February 28th 2011