Welcome to the 15th year of the Wadhurst Astronomical Society and wishing all Members a very prosperous and astronomically exciting New Year!

MEETINGS

COMMITTEE MEETING

       Members of the Committee are respectfully reminded that there will be a meeting of the Committee beginning at 1930 at Phil Berry’s house on Tuesday 11th of January.

       Any member of the Society is welcome to come along but please let Phil know first.

DECEMBER MEETING

The Star of Bethlehem

Brian Mills

        The subject of this month’s talk couldn’t be more appropriate, but with the amount of research Brian has put in, it makes it a great astronomical detective story for Christmas.

        One of the familiar symbols of the Christian Christmas is the Star of Bethlehem, although as Brian points out the star is only mentioned in the Bible in the Book of Saint Matthew, although during his research he found that the star had been briefly mentioned in a book used in the early church that never made it to the New Testament.

        To add more mystery, the Book of St. Matthew was probably written at least 80 years after the birth of Jesus.  Possibly the four gospels were versions aimed at very different audiences and so this could account for the star having only been mentioned in the one account.

        The prediction that “a star out of Jacob would mark the coming of a Messiah” had been made many centuries earlier in the Book of Numbers, and it is believed that wise men had been waiting and preparing for this event.

        Brian presented three options.  A miracle would leave scientists with little evidence to work on.  A legend would be a fictitious account, possibly created to give credence to an earlier prophesy, but if it was a Regular Astronomical Event then evidence must be sought and evaluated. 

        Many translations and interpretations vary significantly but one scholar who has spent a great deal of time studying the star and its background believes that we should think of the relevance of the star’s “heliacal rising”.  During the year, the sun moves eastward slightly each day relative to the background stars and the point at which a star is first seen at dawn in the east after the sun has past it is known as the heliacal rising.  In fact, in the past the rising of Sirius at this point was used to signal the imminent flooding of the Nile.

        Wise men from the east, waiting for a signal, may have seen the star, what-ever it was, at its heliacal rising and began their journey towards Jerusalem.  Brian was keen to point out that the Magi, as the wise men were referred to in St. Matthew’s text, would have probably taken two months to journey towards Jerusalem.  On arrival, they would have sought an audience with King Herod and we know from the scripts that Herod would have considered the arrival of a New King as a threat to his rule, and asked the Magi for details of the star and when it appeared.

        As Brian said, it is curious that Herod had not been notified of the appearance of the star.  The star would have advanced during the past few months since the start of their journey by the Magi and would now have been to the south.  Bethlehem is 6 miles to the south of Jerusalem.

        The next question Brian dealt with was what was the date of Jesus’ birth?  All sorts of complications arise due to confusions with calendars.

        The Roman ten months calendar was in use at the time, then Caesar added two extra months at the beginning of their year making a year 365 days long but he also added a leap year every fourth year; the original Roman year beginning on what we now know as the 26th of March.

        Because this leap year system created a slight over adjustment, Pope Gregory in 1582 removed 10 days and said that only centuries divisible by 400 would be leap years from then on, therefore 1900 wasn’t a leap year and 2000 was.  (Based on all of this, our Financial Year starts on the 5th of April! 25th of March plus 11 days)

        In 525 AD a monk was instructed to work out the date of Christmas using the reigns of Roman Emperors but made the mistake of missing out year ”0” and also the 4 days when Caesar Augustus ruled as “Octavian”.

        It is reasonably certain that Jesus was born in the reign of Herod the Great, in about 5 BC and to support this Brian said Herod died just after an eclipse and the only one to fit the Passover was in 4 BC.  Also, Herod ordered boys under two years old to be killed which probably means that Jesus was considerably less than two.

        Coins dated 4 BC were minted with Herod’s successor.  Another fact Brian mentioned was that Jesus was baptized aged 30 in the 15th year of Tiberius’s reign which means he must have been born after 8 BC.

        The 25th of December was probably chosen as Christmas Day because it already existed as a Pagan festival.  From this information scholars have suggested possible dates in 5 BC of 6th January, 2nd April, 25th March and 19th/20th May; April/March dates being favoured because shepherds would have been in the fields by then.

        According to Eastern folklore wise men were waiting in a cave for three days every year for a star of “unspeakable brightness” to appear.  Brian has read that they were probably from Babylonia and been recording astronomical events for over 600 years BC.

        Finally Brian looked at many possible events that could have alerted the wise men.  Amongst the more likely could have been a planetary conjunction, a Nova or a long lasting meteor although these don’t fulfil the Biblical descriptions.

        One theory suggests that a series of events would have lead to the belief that something momentous was about to happen.

        Amongst possible events could have been three conjunctions of Jupiter and Saturn in 7 BC, a grouping of Jupiter, Saturn and Mars in 6 BC.  Finally there was a nova near the border between Aquila and Capricornus which would have been in the east at dawn at that time.  These events following each other so closely may have been compelling.

        Brian concluded his fascinating talk by saying perhaps more data will be found one day and also that there is no explanation for the star “stopping” over a particular place.

        The talk generated much discussion by members over coffee and mince pies!

JANUARY  MEETING

        Wednesday 19th January 2011 – The January meeting is the start of a new session of the Wadhurst Astronomical Society and begins with the Annual General Meeting.  Following this there is a talk by long time member Bob Seaney.  Bob continues his fascinating look at ancient and forgotten megalithic structures in his talk called “Forgotten Circles”.

        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 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”.

OTHER NOTES AND INFORMATION

SKY NOTES FOR JANUARY

Planets

Mercury has reappeared in the morning skies after its inferior conjunction. By the time of greatest western elongation on January 9th it rises 1½ hours before the Sun. It can be seen above the south eastern horizon a few days prior to this at a height of about 10º (see the diagram below). If you are an early riser there is a better morning apparition of Mercury in late August/early September. If you prefer to look for the innermost planet in the evening then March/April will provide the best views.

Venus is still a morning object in the constellation of Libra shining at magnitude -4.2 in the south east. During the month its phase changes gradually from crescent to gibbous and on the 30th the Moon is (apparently) close by, being just south of Venus. On the 8th it reaches its greatest western elongation.

Mars is approaching a superior conjunction during February and therefore is too close to the Sun to be observable.

Jupiter is still a brilliant object in the south west at magnitude -2.2 lying within the constellation of Pisces. It is always worth looking with binoculars (preferably tripod mounted) to see how many of its bright moons you can see. If you don’t have a tripod, try to find something to steady yourself against - it will make a big difference to how much you can see.

Saturn is a morning object at the start of the month in Virgo at magnitude +0.7 and brightening slowly although by the end of the month it rises before 23.00. In fact it will spend the whole of 2011 within this constellation. As the planet tilts its north pole towards us we will get a better view of the rings than we did last year when they were almost edge on to us.

Uranus is again in conjunction with Jupiter, this time on January 2nd when at magnitude 5.7 it will be just half a degree (a Moon’s width) north of the giant planet. The first map shows the position of Jupiter and Pisces; the second zooms in to show its position more precisely.

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 two diagrams show the last two events listed and where on the Moon’s limb the stars will disappear.

 

Jan

Time

Star

Mag.

Ph

PA °

10th

18.39

SAO 128487

6.8

DD

94

11th

18.43

SAO 109369

6.5

DD

106

14th

19.52

SAO 75755

6.4

DD

100

14th

23.11

SAO 75810

4.8

DD

96

17th

20.31

SAO 77915

4.3

DD

65

Phases of the Moon for January

 

New

First ¼

Full

Last ¼

4th

12th

19th

26th

 

ISS

        Below are details of passes of the ISS as seen from Wadhurst that are brighter than mag. -3.0. 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 be able to see it for a few minutes before and after these times.  Times are in GMT.

 

Jan.

Mag

Time

Alt°

Az.

1st

-3.1

17.03

51

SSE

2nd

3.7

17.28

87

SSE

3rd

-3.7

17.53

76

N

4th

-3.6

16.42

88

SSE

4th

-3.3

18.17

62

WNW

5th

-3.7

17.07

76

N

6th

-3.7

17.32

86

N

7th

-3.6

16.21

76

N

7th

-3.3

17.57

62

SSW

8th

-3.7

16.46

87

N

9th

-3.1

17.11

60

SSW

 

Iridium Flares

        The flares that I’ve listed are brighter than magnitude -4 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. The flare on the 15th (caused by the satellite Iridium 4) is magnitude -8 which is about as bright as flares can be, so it will be worthwhile looking if the sky is clear.  Times are in GMT.

 

Jan.

Time

Mag

Alt°

Az.

2nd

16.48

-5

25

WNW

7th

17.29

-4

28

S

13th

17.12

-5

23

SSW

15th

18.26

-8

36

SSE

18th

17.00

-6

18

SW

19th

17.53

-5

13

WNW

19th

18.10

-7

36

S

21st

17.23

-6

19

WNW

23rd

17.02

-5

22

W

23rd

17.55

-7

35

S

27th

17.40

-7

34

S

30th

19.00

-5

41

SSE

31st

17.25

-6

32

SSW

 

Solar Eclipse

        There will be a partial solar eclipse on January 4th beginning before sunrise for UK observers. From these latitudes the Sun rises at around 08.06 with maximum eclipse occurring at 08.15 when 75% of the solar disk will be obscured. The eclipse is over for us at 09.34. The Sun’s proximity to the horizon along with any atmospherics could make for some interesting photographs. Incidentally this is an eclipse that isn’t visible as total anywhere.

 

Meteors

        The Quadrantid meteor shower is active from January 1st to the 6th with maximum occurring around midnight on the night of the 3rd/4th when the ZHR is predicted to be around 80, but could possibly be as high as 120. The disadvantage is that although the radiant is circumpolar it is low in the sky until after midnight. The good news is that because there is a solar eclipse on the day of maximum, the Moon is new so will cause meteor watchers no problems. If skies are clear it could be well worth wrapping up warmly for an hour or so. The diagram shows the position of the radiant close to Ursa Major in what is now the constellation of Boötes.

 

The Night Sky in January

        Looking north at 22.00 around the middle of January the bright star Vega is just on the horizon. Ursa Major is standing on its tail, whilst on the other side of the pole Casiopeia and Cepheus (both circumpolar constellations) are gradually slipping lower in the sky. The head of Draco is on the meridian at its lowest point of the year. In the east both Cancer and Leo are fully risen whilst the long straggling shape of Hydra has begun to make an appearance. In the south the striking shape of Orion is on the meridian whilst around him all the other winter constellations are on show. Canis Major and Minor, Gemini and Taurus, whilst overhead is the brilliant Capella in Auriga. Lastly, if we look west the Square of Pegasus, Cetus and Pisces  are all close to the horizon. Now may be your last chance to catch site of the Great Andromeda Spiral before it is lost in the evening glow.

What’s Happening in 2011

Late March to early April - best evening apparition of Mercury.

11th May - Grouping in the dawn skies of Mercury, Venus and Jupiter.

15th June - Total lunar eclipse - the Moon rises during totality.

Late August to early September - Good morning apparition of Mercury.

8th October - Possibility of a meteor storm from the Draconids.

10th December - Total lunar eclipse - at moonrise totality is already over.

Brian Mills

DEFINITIONS OF TERMS USED IN ASTRONOMY

Aphelion

        The path of the Earth around the Sun is not circular but is an ellipse which means the distance between the two bodies varies. Aphelion refers to the point in the Earth’s orbit when it is furthest away from the Sun, something that will occur on July 4th 2011 at 15.00 hrs. At this time we will be just over 94½ million miles apart.

Perihelion

        As you might expect this refers to the moment when the Earth is at its closest to the Sun. In 2011 this occurs on January 3rd at 19.00 hrs when we will be just under 91½ million miles away. Of course for those of us in the northern hemisphere this coincides (rather surprisingly perhaps) with our winter.

Apogee

        This orbit of the Moon around the Earth is also an ellipse with eccentricity of between 5% and 6% which is quite high. Apogee is the point at which the Moon is at its furthest from Earth and on average is just over 251,500 miles.

Perigee

        This refers to the point in the Moon’s orbit around the Earth when the two bodies are at their closest and equates to a distance of just over 225,100 miles.

        Some people believe they can tell the difference in apparent size of the Moon when seen at its two extremes. Below are pictures of both for you to compare.

Brian Mills

NASA’S SPACE PLACE

Astronomers Stumble onto Huge Space Molecules

By Trudy E. Bell and Tony Phillips

Deep in interstellar space, in a the swirling gaseous envelope of a planetary nebula, hosts of carbon atoms have joined together to form large three-dimensional molecules of a special type previously seen only on Earth. Astronomers discovered them almost accidentally using NASA's Spitzer Space Telescope.

“They are the largest molecules known in space,” declared Jan Cami of the University of Western Ontario, lead author of a paper with three colleagues published in Science online on July 22, 2010, and in print on September 3.

Not only are the molecules big: they are of a special class of carbon molecules known as “fullerenes” because their structure resembles the geodesic domes popularized by architect Buckminster Fuller. Spitzer found evidence of two types of fullerenes. The smaller type, nicknamed the “buckyball,” is chemical formula C60, made of 60 carbon atoms joined in a series of hexagons and pentagons to form a spherical closed cage exactly like a black-and-white soccer ball. Spitzer also found a larger fullerene, chemical formula C70, consisting of 70 carbon atoms in an elongated closed cage more resembling an oval rugby ball.

Neither type of fullerene is rigid; instead, their carbon atoms vibrate in and out, rather like the surface of a large soap bubble changes shape as it floats through the air. “Those vibrations correspond to wavelengths of infrared light emitted or absorbed—and that infrared emission is what Spitzer recorded,” Cami explained.

Although fullerenes have been sought in space for the last 25 years, ever since they were first identified in the laboratory, the astronomers practically stumbled into the discovery. Co-author Jeronimo Bernard-Salas of Cornell University, an expert in gas and dust in planetary nebulae, was doing routine research with Spitzer's infrared observations of planetary nebulae with its spectroscopy instrument. When he studied the spectrum (infrared signature) of a dim planetary nebula called Tc 1 in the southern-hemisphere constellation of Ara, he noticed several clear peaks he had not seen before in the spectra of other planetary nebulae.

“When he came to me,” recounted Cami, an astrophysicist who specializes in molecular chemistry, “I immediately and intuitively knew it I was looking at buckyballs in space. I've never been that excited!” The authors confirmed his hunch by carefully comparing the Tc 1 spectrum to laboratory experiments described in the literature.

“This discovery shows that it is possible—even easy—for complex carbonaceous molecules to form spontaneously in space,” Cami said. “Now that we know fullerenes are out there, we can figure out their roles in the physics and chemistry of deep space. Who knows what other complex chemical compounds exist—maybe even some relevant to the formation of life in the universe!”

Stay tuned!

Learn more about this discovery at:

http://www.spitzer.caltech.edu

For kids, there are lots of beautiful Spitzer images to match up in the Spitzer Concentration game at:

http://spaceplace.nasa.gov/en/kids/spitzer/concentration.

buckyballs.jpg

Caption:

Superimposed on a Spitzer infrared photo of the Small Magellanic Cloud is an artist's illustration depicting a magnified view of a planetary nebula and an even further magnified view of buckyballs, which consist of 60 carbon atoms arranged like soccer balls.

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 February 2011 Newsletter should be with the Editor by January 28th 2011