Text Box:  WADHURST ASTRONOMICAL SOCIETY

OCTOBER NEWSLETTER 2008

INDEX: MEETINGS, OTHER NEWS, CONTACTS

MEETINGS

 

MEETINGS

COMMITTEE MEETING

The Committee are respectfully reminded that there is a meeting of the Committee on Tuesday 7th October 2008 beginning at 1930.  The venue, as usual, is the Abergavenny Arms in Frant.
As always, any Society member is very welcome to come along and join us.  The meeting usually lasts an hour and member’s ideas and views are essential to the running of our Society.

SEPTEMBER MEETING

The meeting began with a few announcements by Phil Berry.  Phil had once again assisted on the SAGAS (Southern Area Group of Astronomical Societies), also helping to promote the Wadhurst Astronomical Society.
Members were pleased to hear that Mike Wyles, our Treasurer, had undergone a successful heart operation since our last meeting in July and had come along to this evening’s meeting with Phil.  Mike was looking remarkably well.

Phil then introduced the evening’s speaker.

An Enthusiastic Amateur’s Journey in Astrophotography
Given by John Punnett

John Punnett is a member of the Orpington Astronomical Society and was giving this talk to a group for the first time. The word “Enthusiastic” was shown in red in the title and John explained that the word truly was necessary to explain his dedication to his chosen subject.

The first image he acquired was in 2002 using a Russian Zenith E camera which is probably known to a number of amateur astronomers.  The picture was of a partial eclipse of the moon. John’s interest and success spurred him on to obtain a Tasco refracting telescope he called “El Cheapo” with which he obtained images of the moon and Jupiter.
He realised that he needed to buy a better instrument and acquired a Russian TAL-2M 6-inch f8 reflecting telescope on a driven equatorial mount.  He now had to deal with new issues such as polar alignment, collimating and a German equatorial mount.

About this time John stumbled across an internet website giving a vast amount of very useful information about the use of webcams in astrophotography at:
http://tech.groups.yahoo.com/group/QCUIAG/. 

He purchased a Philips ToUcam colour video format webcam for just over £50.
After removing the lens to fit it onto the eyepiece of his telescope using an adaptor, he found this to be a good camera for imaging the planets and the Moon.  An advantage was that it could be accessed through the USB port of his computer. The camera was sensitive enough to respond down to less than 1 lux and had a shutter speed down to 1/25th of a second.
John’s first images were of the moon with lots of brightness and good detail to focus on. He saved a series of images of one area on his computer as an AVI file and then used a programme called RegiStax to process these to end up with one image made from the best individual images. Version 4 of RegiStax can be downloaded free from the internet together with the manual which carries loads of information about using the software.  The web address is at the end of this article. RegiStax lines up the best images then processes them to achieve detail not seen in any of the individual images.  Some times as many as 600 images may be needed.

We were shown some of the first images of the moon that John had processed.  They were very good and enough to spur anyone to try their hand at webcam imaging.  But then he went on to describe his next stage. First the eyepiece was adapted so that it could be focussed using a small electric motor, making focussing a lot easier.
Then we were shown a superb mosaic image of the moon, built up from a large number of images taken with the webcam.  Locking off the telescope the video images were obtained and recorded as the moon passed through the field of view due to the earth’s rotation.  The mosaic comprised 26 processed images “stitched” together using “iMerge”.  This internet address is shown below.

We now looked at the planets and for this John recommended using a 3x Barlow or more achieving at least f30.  Focussing is difficult but worth persevering with.  Taking as many frames as possible and selecting only the best, he showed some excellent images of Saturn revealing its moons and also of Jupiter in considerable detail and showing the Red Spot.
A number of images of Mars were placed on a solar diagram showing the positions in its orbit relative to the Earth’s orbit.

John showed an image of a sunspot using a Baader solar filter to achieve the correct exposure.  The detail was quite impressive.  Also we were shown images taken during the transit of Venus across the Sun in 2004.

One thing John was keen to do was to attempt deep sky imaging but using the webcam in its original state with a maximum of 1/25th of a second and the sensitivity being reduced by a built in colour filter in the CCD he thought this not worth trying. Instead he modified the webcam with some help from Steve Chambers so that the shutter could be held open for long exposures and then replaced the CCD chip itself with a more sensitive B&W chip costing around £35. Now the results were astonishing.  We were first shown NGC 891 in Andromeda.  The dark lanes were very clear and the background sky was relatively noise free.  Fifty ten-second exposures had been used.

Next John purchased a set of colour LRGB filters, although these cost over £100 but the results were worth it.  M51 and the Veil nebula proved this easily, and was enough to convince anyone that webcam imaging was in the realms of any of us. John’s next step was to buy a dedicated Astro-imaging camera.  Enter the Atik 16ic. This is a relatively low cost, extremely sensitive CCD camera.  It uses a Peltier cooling device to reduce electronic noise in the circuitry and produces FITS files instead of AVI files.  This is the format most often used in astronomy.

The images obtained were clear, sharp and with very little noise.  We saw a number of deep sky images all of which can be seen on John Punnitt’s web site, shown below.
To complete the methods of imaging John had used, he told us about the use of Digital single-lens reflex cameras.  These are high resolution single shot colour digital cameras and are good for wide field-of-view shots.  Lots of shots can be taken for later stacking to reduce noise. Two things we were advised to take into account of; shoot in RAW format and always have spare batteries!

John’s current set-up is an MN56 Maksutov- Newtonian telescope on an EQ6 Pro mount.  The CCD is the Atik 16ic and the finder is WO ZS66 with his modified TouCam used as a guider.

Members were very impressed with the very low cost of achieving such good results and without doubt, John’s Enthusiasm ruled the day.
Below are some of Johns suggested Internet websites:

Registax - http://www.astronomie.be/registax/
Excellent freeware for stacking & processing lunar and planetary images
K3CCDTOOLS - http://www.pk3.org/Astro/index.htm?k3ccdtools.htm
Excellent software for video capturing, auto-guiding and post processing
iMerge - http://www.geocities.com/jgroveuk/iMerge.html
Again Excellent freeware for image stacking and mosaic making
QCUIAG - http://tech.groups.yahoo.com/group/QCUIAG/
Astronomy group for webcam imaging

OCTOBER MEETING
Wednesday 15th October 2008 The meeting will include two video half-hour lectures.   They attempt to cover Einstein’s Special Theory of Relativity.  These are part of the series of video lectures we have used previously and they are presented in a way that is clear and easy to understand.

The meeting begins at 1930 although members are invited to arrive anytime after 1900.  This is a good time to exchange ideas and discuss problems. The venue as always is in the Upper Room of the Methodist Church at the east end of Wadhurst Lower High Street, opposite Uplands College.  (For those with SatNav – the post code is TN5  6AX)

FUTURE MEETINGS
Wednesday 19th November 2008  Details to follow.

Wednesday 10th December 2008 Please note that as it is December, the Society meets on the Second Wednesday instead of the third as in other months.
Paul Treadaway, who is a member of the Society, gives a talk about the birth of stars.
Members will remember the talk Paul gave last year and will recall the intriguing scenarios he gave us to think about.

Wednesday 21st January 2009 This is the Annual General Meeting.  That should not take too long and then Phil Berry gives a fascinating talk, bringing us up to date with the impressive progress he has achieved with his observatory.  This time Phil calls his talk “The Further Trials and Tribulations of an Amateur Astronomer”.

OTHER NEWS AND INFORMATION

SKY NOTES FOR OCTOBER
Planets

Mercury will be a morning object towards the end of the month, visible for around ninety minutes before sunrise. Its maximum magnitude will be -0.8, making this the best morning apparition of Mercury this year. The best days to look are between the 20th and 30th, whilst on the 27th the moon will be just west of the planet.

Venus, at magnitude -4, is an evening object setting in the west around one hour after the sun.

Mars is unsuitably placed for observation this month.

Jupiter is still a conspicuous evening object although it is fairly low in the south in the constellation Sagittarius. At magnitude -2.3 (mid-month) it cannot be confused with anything else in that part of the sky. A small telescope or binoculars are all that is needed to show the four main satellites Io, Europa, Ganymede and Callisto.

Saturn is a morning object (mag. +1) in the constellation of Leo rising more than three hours before the sun by the middle of the month. Saturn’s ring system continues to become more edge-on as seen from Earth.

Lunar Occultations
As usual I’ve only included events for stars down to around magnitude 7.5 that occur before midnight. DD = disappearance at the dark limb. Times are all BST. If you are an early riser you can watch the re-appearance of the magnitude 3.9 star, Delta Cancri, from behind the moon’s dark limb at 07.03 on October 22nd.
If the weather looks promising it may be an idea to try and observe an ordinary occultation in a group, possibly from the field in Wadhurst that we have used after the regular meetings. I know there are several telescopes that belong to the Society that would, I’m sure, be quite adequate if anyone is interested to do this.

Oct

Time

Star

Mag.

Ph

PAo

5th

1919

SAO 185573

6.8

DD

51

6th

1937

SAO 186937

7.8

DD

56

8th

2052

SAO 189114

5.9

DD

69

8th

2057

SAO 189120

7.8

DD

116

8th

2309

SAO 189195

7.8

DD

76

9t

2101

SAO 164156

6.2

DD

48

11th

1954

SAO 146273

6.4

DD

76

12th

1837

SAO 146735

6.9

DD

59

Phases of the Moon for October

New

First Quarter

Full

Last Quarter

28th

7th

14th

21st

ISS
There are a large number of passes of the ISS this month as seen from Wadhurst but many are low in the sky or occur in the early hours of the morning. I have only included those that are the brightest, attain reasonable altitude and occur before midnight. The information given is for when it is at maximum altitude, so it is best to look some minutes before this time. Full details of all passes can be found at: - www.heavens-above.com  Times are all BST.

October

Magnitude

Time BST

Altitude

Azimuth

1st

-2.3

1926

81

N

1st

-0.2

2100

25

WSW

2nd

-2.2

1952

70

SSW

3rd

-2.3

1843

83

N

3rd

-1.2

2018

36

SSW

4th

-2.1

1909

66

SSW

5th

-0.9

1936

33

SSW

Meteors
The only meteor shower of any note during October is the Orionids. They begin on the 16th and end on the 27th with maximum occurring on the 20th when the ZHR (Zenithal hourly rate) would be expected to reach around 25. Unfortunately this year the moon is at last quarter and rises around the same time as the radiant on the night of maximum activity.

An Observation
On the evening of 12th September around 17.35 I was outside opening up the observatory when I noticed a bright star-like object high in the sky in the south west. The sky was still light and no other astronomical object was visible. I trained the telescope on it and found quite surprisingly that I could resolve it into a disk but stranger still I could see an object to one side that was spinning and flashing (presumably reflected sunlight). I rang Geoff Rathbone as his was the only number I had to hand but it occurred to both of us that it would have been handy to have phone numbers for members who would be interested to hear of such things so that they could immediately look for themselves and possibly verify the sighting.
Fortunately the object was seen by someone else who saw what he believes to have been a balloon of some sort jettison the object below it in a shower of sparks. Sadly I was indoors at that exact moment typing a message to see if anyone else had seen it!

Don’t forget British Summer Time ends on Sunday 26th October at 02.00 hrs.

NASA SPACE PLACE

Extreme Starburst  by Dr. Tony Phillips

A star is born. A star is born. A star is born.

Repeat that phrase 4000 times and you start to get an idea what life is like in distant galaxy J100054+023436. Astronomers using NASA's Spitzer Space Telescope and ground-based observatories have found that the galaxy gives birth to as many as 4000 stars a year. For comparison, in the same period of time the Milky Way produces only about 10. This makes J100054+023436 an extreme starburst galaxy. “We call it the ‘Baby Boom galaxy,” says Peter Capak of NASA’s Spitzer Science Centre at the California Institute of Technology in Pasadena, CA. "It is undergoing a major baby boom, producing most of its stars all at once. If our human population was produced in a similar boom, then almost all people alive today would be the same age." Capak is lead author of a paper entitled "Spectroscopic Confirmation of an Extreme Starburst at Red shift 4.547" detailing the discovery in the July 10th issue of Astrophysical Journal Letters.

The galaxy appears to be a merger, a “train wreck” of two or more galaxies crashing together. The crash is what produces the baby boom. Clouds of interstellar gas within the two galaxies press against one another and collapse to form stars, dozens to hundreds at a time.

This isn’t the first time astronomers have witnessed a galaxy producing so many stars. “There are some other extreme starburst galaxies in the local universe,” says Capek. But the Baby Boom galaxy is special because it is not local. It lies about 12.3 billion light years from Earth, which means we are seeing it as it was 12.3 billion years ago. The universe itself is no older than 14 billion years, so this galaxy is just a youngster (Capak likens it to a 6-year-old human) previously thought to be incapable of such rapid-fire star production. The Baby Boom galaxy poses a challenge to the Hierarchical Model of galaxy evolution favoured by many astronomers. According to the Hierarchical Model, galaxies grow by merging; Add two small galaxies together, and you get a bigger galaxy. In the early years of the universe, all galaxies were small, and they produced correspondingly small bursts of star formation when they merged. “Yet in J100054+023436, we see an extreme starburst. The merging galaxies must be pretty large.”

Capak and colleagues are busy looking for more Baby Boomers “to see if this is a one-off case or a common occurrence.” The theory of evolution of galaxies hangs in the balance.
Meanwhile… A star is born. A star is born. A star is born.

See more breathtaking Spitzer images at:
www.spitzer.caltech.edu/Media/mediaimages. Kids can play the new Spitzer “Sign Here!” game at:
http://spaceplace.nasa.gov/en/kids/spitzer/signs.
This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Any material for inclusion in the November Newsletter should be with the Editor by 28th October 2008

CONTACTS

Chairman   John Vale-Taylor 

Phil Berry  01892 783544

Treasurer  Mike Wyles  01892 542863

Publicity & Website  Michael Harte  01892 783292

Newsletter Editor  Geoff Rathbone  01959 524727

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