MEETINGS

 

APRIL MEETING

 

        Phil Berry opened the evening by saying that there were still places left for "An Evening with Don Goldman" in association with Wadhurst Astronomy Club and IanKingImaging Ltd and is free.

        Ian King has booked the Wadhurst Methodist Church hall for Thursday 12th May - 1900 to 2200 when Don Goldman is going to give two 1 hour talks on Image Processing for beginner to intermediate Astro-imagers and Narrow Band Filters and Narrow Band Image Processing

        Don Goldman is the CEO and designer of Astrodon Filters

        He is also a very experienced and world renowned Astro-imager.  Full details of the talks can be found here

         To book just email Ian with your name with a subject of "An Evening with Don Goldman".

 

        Phil then introduced this evening’s speaker who was the director of the ICI laboratories before they were broken up.  He maintains a great interest in the history of science which leads him to give tonight’s talk:

 

The Life and Times of Galileo

Dr. John Lawrence

 

        John began by filling in the background of Galileo’s life.  Galileo was born in 1564 in Pizza but at the age of 10 moved to Florence and was educated in a monastery just outside the city. In 1581 at the age of 17 he enrolled at the university of Pizza to do a medical degree, despite being more interested in mathematics and science.

        He gave up studying for a medical degree four years later to study mathematics which he went on to teach and taking the Chair of Maths at Pizza university in 1585 having established quite a reputation as a mathematician.

        He now began to develop an interest in astronomy and particularly the Copernicus theory of the solar system which was against the teachings of the Roman Catholic church which believed in the ideas of Ptolemy and Aristotle who said that the Earth was the centre of the solar system.

        Galileo heard about a combination of lenses being combined to see distant object and then John said that there was a story, possibly apocryphal, that in 1609 a spectacle maker’s children combined two lenses and found they were able to see the church tower enlarged.  They were said to have told their father, Hans Lippershey, who put the lenses together in a tube and so made the first telescope.

        Having heard about this telescope, Galileo set about making his own vastly superior telescope with a magnification of 8 or 9 times.

        Following his interest in astronomy, John told us that Galileo now turned the telescope towards the moon, which revealed to him the mountains and craters.  He also discovered that the Milky Way was in fact made up of stars and that Jupiter had 4 moons making notes of the movement of the Jovian moons.

        In 1610, when Galileo was 46 years old he observed the phases of Venus, showing that the planet orbits the sun and establishing that Copernicus was right, although about that time, Tycho Brayhe agreed with this but pronounced that the sun orbits the earth, yet this didn’t fit the mathematics of what was being observed.

        The Jesuits in Rome were beginning to regard Galileo as a dangerous opponent to their teachings although he was careful not to publish his ideas.

        In 1616, Galileo visited Rome to see what the churches view of the solar system was, but was told by Pope Paul the fifth not to talk about the Copernicus theory.  Galileo interpreted this to mean he could still hold the theory as an alternative idea.

        John went on to tell us that not all Galileo’s theories were right; he believed that comets were near earth objects and may even be in the earth’s atmosphere.  He also believed that sun spots were in fact planets or clouds crossing the surface of the sun.

 

        In 1623, Pop Urban the eighth took the papacy and was a great admirer of Galileo, and now Galileo decided to publish something on the Copernicus issue but before it was published, in 1625 he was warned about feelings in Rome by the Assayer.

        In 1632 he went ahead with the publication, being financed from Florence, not Rome, but now Pop Urban felt that Galileo had miss-written the book although the book was found to be a great success.

        An inquisition was formed to examine Galileo’s reasons for publishing his book.  The trial is related in detail by his eldest daughter, Maria Celeste, and is now published in a book called “Galileo’s Daughter” by Dava Sobel which is where John Lawrence found a good deal of information for this talk.

        Much of the trial was related by John, and it certainly appeared to have been a show-trial, revealing how the church regarded any challenge to their authority.

        Galileo was found guilty of heresy and sentenced to imprisonment for life although this was commuted to house arrest, not even being allowed visitors.  But a year later Pop Urban relented a little and allowed his eldest daughter to visit him.

        The book was banned by Rome but copies had already been smuggled to Holland in 1638.

        On January the 8th 1642, Galileo died at the age of 77.  He is buried in the Basilica of Santa Croce.  After his death, attempts to restore Galileo’s reputation were undertaken and later parts of his book were allowed by the Catholic church to be reprinted.

        Only as recently as 1992 did Pop John Paul the Second expressed regret of the handling of Galileo’s affairs by the Catholic Church.

        John Lawrence ended his fascinating look at the life of the builder of the first proper telescope by suggesting that details of the trial can be read in Dova Sobels’s book “Galileo’s Daughter”, published by Fourth State publishing; ISBN 1-85702-816-9.

 

UNUSUAL NOTES FROM THE SCIENTIFIC WORLD

 

        Once again, John Wayte gave us a glimpse of another story from the world of science.  Last month he told us about the highest temperatures to be found.  This month his subject was on some of the coldest temperatures known.

        One of the coldest spots to be found is on the moon in one of the dark craters where the temperature is as low as 33 Kelvin.

        The background radiation in space gets down to about 2.7 K, but there is a rapidly expanding gas cloud called the Boomerang nebula where the temperature measures 1 K.

        John asked if we could guess where the coldest temperature is to be found.  Following last month’s chat on the highest temperature, which was in Switzerland, no one was surprised to find that the lowest temperature also was on earth.  This time the extreme lowest temperature was in a laboratory in Massachusetts where scientists had chilled some sodium atoms to within half a billionth of absolute zero!

 

FROM OUR DIRECTOR OF OBSERVATIONS

 

        Brian Mills gave his monthly talk about finding your way round the night sky, with many tips on star-hopping to find ones way round the constellations.  More in the Sky Notes.

 

 

MAY  MEETING

 

        Wednesday 18th May 1022 – Peter Gill in a return visit, will be giving an illustrated talk called “The Sun”

        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 15th June 2011 – Telescope Evening.  This is an meeting when we have short talks on various astronomical subjects and there will be demonstrations of using equipment and software.  Members are encouraged to bring their telescopes and talk about what they use them for.

 

        Wednesday 20th July 2011 – Details to follow

 

 

OTHER NOTES AND INFORMATION

 

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.

        Many thanks to those members who have already renewed their subscription.

 

 

 

SKY NOTES FOR MAY

 

Planets

 

Mercury is a morning object and reaches its greatest western elongation (see diagram) on May 7th. Sadly for UK observers it will be very difficult to see as it rises just before the Sun.

 

 

This is a problem at certain times of year because of the angle the ecliptic makes with the horizon. You can see from the diagrams how this angle changes if we compare the eastern horizon in the middle of April with that in the middle of October.

 

 

 

 

In fact around the middle of May there is a massing of planets in the morning sky that sadly for us is likely to go largely unseen. This is a real shame as Mercury, Venus, Mars and Jupiter are all very close together with Uranus not far away as you can see from the diagram that is drawn with the Sun just below the horizon.

 

 

 

Venus as shown in the diagram rises only just before the Sun and is heading towards a superior conjunction on August 16th.

 

Mars is just emerging into the morning sky following its conjunction with the Sun on February 4th. It will gradually become better placed for observation although it won’t come to opposition until March 3rd 2012 when its apparent diameter will be 13.9 arc seconds and its magnitude will be minus 1.2.

 

Jupiter again is a morning object, although by the end of July it will rise before midnight BST. It will come to opposition on October 29th.

 

Saturn is visible for most of the night in Virgo although its brightness is dropping slightly as the ring angle as seen from Earth decreases. Saturn can be located by first using the Plough to find Leo and then by using the back of the lion to point roughly to the ringed planet’s location. Alternatively you can use a curved line from the tail of Ursa Major through Arcturus in Boötes round to Spica in Virgo.

 

 

 

 

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 at more unsociable hours.  DD = disappearance at the dark limb.

Times are in BST.  

 

May

Time

Star

Mag.

Ph

PA °

6th

20.42

SAO 77420

6.3

DD

62

7th

23.41

SAO 78691

7.0

DD

103

12th

22.32

66 Leonis

6.8

DD

169

14th

20.44

SAO 157618

6.3

DD

113

 

 

Phases of the Moon for May

 

New

First ¼

Full

Last ¼

3rd

10th

17th

24th

 

 

ISS

Below are details of the only passes of the ISS that occur before midnight as seen from Wadhurst that are magnitude -2.0 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 and directions shown below are for when the ISS is at it’s maximum elevation, so you should go and look a few minutes before. Times are in BST.

 

 

May

Mag

Time

Alt°

Az.

1st

-3.1

20.48

49

SSW

2nd

-2.0

21.12

24

SSW

 

 

Iridium Flares

The flares that I’ve listed are magnitude -4 or brighter 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 BST.

 

 

May

Time

Mag

Alt°

Az.

3rd

23.10

-6

24

W

5th

23.07

-4

22

W

6th

23.01

-5

22

W

6th

23.02

-7

22

W

8th

22.58

-6

20

W

10th

22.55

-6

18

W

12th

22.53

-6

15

WNW

13th

23.45

-6

39

WSW

16th

21.37

-4

17

NNW

17th

23.30

-5

38

WSW

21st

23.15

-7

35

WSW

22nd

23.11

-4

34

WSW

25th

23.00

-5

31

W

28th

22.51

-7

28

W

31st

22.42

-4

26

W

31st

23.26

-4

13

NNE

 

 

The Night Sky in May (Written for 2200 BST mid month)

In the north Ursa Major and Cassiopeia are both on the meridian although they are of course on opposite sides of the celestial pole. Capella is dropping towards the northern horizon (although it will never set) whilst two of the stars of the Summer Triangle are climbing away from it.

Looking east we see that Hercules, Ophiuchus and the two parts of Serpens have all risen although none of them have the same visual appeal as the winter constellations.

In the south Saturn (in Virgo) is on the meridian whilst just below are the small constellations of Crater and Corvus that lie on the back of Hydra the water snake.

Towards the west, Orion and his retinue have gone and soon to follow are Gemini and Cancer.

 

 

Advance Warning for June.

There is a total eclipse of the Moon on June 15th. The eclipse is already total when the Moon rises at 21.15 hrs BST.

 

Brian Mills

 

 

DEFINITIONS OF TERMS USED IN ASTRONOMY

 

The Zodiac.

The term “Zodiac” refers to the band of sky that is centred on the ecliptic (the Sun’s path across the sky) and extends 8° either side of it. Within this band can be found not only the Sun but also the Moon and planets. We know from Astrology (!) that twelve constellations lie along the Zodiac. In fact this is incorrect as Ophiuchus (part of which protrudes between Scorpius and Sagittarius) is also a Zodiacal member - a fact that seems to be ignored by Astrologers.

 

Precession.

This describes the gradual movement of the Earth’s axis and can be likened to a spinning top except that in our planets case both ends of the axis of rotation sweep out cone shapes in space. One complete rotation takes in the order of 26,000 years, so we are fortunate that at the moment the moderately bright star Polaris marks the north celestial pole almost exactly although it is rarely the case that a star is so conveniently situated. 3,000 years ago the star Thuban in the constellation of Draco was the “Pole Star” and in 12,000 years time Vega will claim that role although it will always be at least 5° away from the pole.

Precession occurs because the Earth is not a perfect sphere but has an equatorial “bulge” i.e. it measures around 70 miles more around the equator than it does around the poles. Because the Earth’s axis is tilted this bulge is off centre and the part of the bulge closest to the Sun suffers more from gravitational attraction (gravity decreases with distance) than the rest. It was Hipparchus the Greek astronomer who discovered precession probably around 150BC, but it was Isaac Newton who first explained the cause.

 

Brian Mills

 

 

NASA’S SPACE PLACE

 

Cosmic Recount

by Dr. Tony Phillips

 

News flash:  The Census Bureau has found a way to save time and money.  Just count the biggest people.  For every NBA star like Shaquille O’Neal or Yao Ming, there are about a million ordinary citizens far below the rim.  So count the Shaqs, multiply by a million, and the census is done.

Could the Bureau really get away with a scheme like that?  Not likely. Yet this is just what astronomers have been doing for decades.

Astronomers are census-takers, too.  They often have to estimate the number and type of stars in a distant galaxy. The problem is, when you look into the distant reaches of the cosmos, the only stars you can see are the biggest and brightest. There’s no alternative.  To figure out the total population, you count the supermassive Shaqs and multiply by some correction factor to estimate the number of little guys.

The correction factor astronomers use comes from a function called the “IMF”—short for “initial mass function.” The initial mass function tells us the relative number of stars of different masses. For example, for every 20-solar-mass giant born in an interstellar cloud, there ought to be about 100 ordinary sun-like stars.  This kind of ratio allows astronomers to conduct a census of all stars even when they can see only the behemoths.

Now for the real news flash: The initial mass function astronomers have been using for years might be wrong.

NASA’s Galaxy Evolution Explorer, an ultraviolet space telescope dedicated to the study of galaxies, has found proof that small stars are more numerous than previously believed.

“Some of the standard assumptions that we've had—that the brightest stars tell you about the whole population—don’t seem to work, at least not in a constant way,” says Gerhardt R. Meurer who led the study as a research scientist at Johns Hopkins University, Baltimore, Md.  (Meurer is now at the University of Western Australia.)

Meurer says that the discrepancy could be as high as a factor of four.  In other words, the total mass of small stars in some galaxies could be four times greater than astronomers thought. Take that, Shaq!

The study relied on data from Galaxy Evolution Explorer to sense UV radiation from the smaller stars in distant galaxies, and data from telescopes at the Cerro Tololo Inter-American Observatory to sense the “H-alpha” (red light) signature of larger stars.  Results apply mainly to galaxies where stars are newly forming, cautions Meurer.

“I think this is one of the more important results to come out of the Galaxy Evolution Explorer mission,” he says. Indeed, astronomers might never count stars the same way again.

Find out about some of the other important discoveries of the Galaxy Evolution Explorer at http://www.galex.caltech.edu/. For an easy-to-understand answer for kids to “How many solar systems are in our galaxy?” go to The Space Place at:  http://tiny.cc/I2KMa

 

 

big-and-small-stars.jpg

Caption:

Astronomers have recently found that some galaxies have as many as 2000 small stars for every 1 massive star.
They used to think all galaxies had only about 500 small stars for every 1 massive star.

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

 

 

 

 

 

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 June 2011 Newsletter should be with the Editor by May 28th 2011