Occultation of the Pleiades

7th August 2007

Observers' Reports

Congratulations to all those members who sent in images and timings of this most beautiful event. Most of the country had fine weather during the early hours of the morning, with the result that many people were able to enjoy the juxtaposition of the waning crescent moon with that most beautiful open cluster, "The Seven Sisters" Even more impressive were the reappearances of the brighter stars from behind the "earthlit" dark limb. The next Occultation of the Pleiades is due on October 27, late evening, and again on December 21, mid evening.

Jon Harper,
SPA Occultation Section Director

Index of Reports

Many of the images in this report have been resized to fit within the space available, and in each case clicking anywhere over the image will display the higher resolution version.

Mike Feist - Brighton, Sussex

The sky was superbly clear - Neptune could be seen in 8 x 32 binoculars.

From my garden the Crescent Moon with Earthshine appeared at 0033 BST with the terminator at Clavius. At 0041 BST I used the 8 x 32 to make a sketch of the Moon approaching the star cluster. I also set up a 50mm spotting scope on a tripod for a more detailed view.

I saw the following events at the following times. (These are just "alarm clock times" and not scientific timings.)

Disappearance, at bright limb, Taygeta = 0121 BST
Disappearance, at bright limb, Maia = 0126 BST
Reappearance, at dark limb, Electra = 0145 BST
Reappearance, at dark limb, Celaeno = 0155 BST
Reappearance, at dark limb, Taygeta = 0205 BST
Reappearance, at dark limb, Electra = 0220 BST

Merope missed by about one quarter of the Moon's diameter.

Alcyone missed by about one sixth of the Moon's diameter.

At 0210 BST I made a sketch, using 8 x 32, showing the Moon sitting in the "bowl" of the Pleiades rather like an egg sitting in a spoon!

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Peter Grego - Rednal, Birmingham

So far it's mid-event and rather lovely to see my old friend Luna in among the Seven Sisters. I attach an initial shot, taken with an undriven DSLR. Not the greatest astrophoto ever, but shows the earthshine nicely!

I must admit that I was so bowled over by the binocular view of the Pleiades occultation this morning, perfectly framed as it was beneath some oak branches, that alas, I never attempted any timings. The last event like this I saw was in August 1988, and that was also magical.

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Simone Bolzoni - Busto Arsizio, Italy

I have just followed the various occultations and send you the first image, not processed yet. Newton telescope 12cm f/6 at prime focus, Canon 350D, 0,5 seconds exposure at 1600 ISO. 1.22 UT, just after reappearance of 22 Tau, the last "important" star occulted. Simone then went on to send several more images which now follow:

Do take a look at Simone's superb processed images. They are to be found at his excellent web-site.

Here's one of them:

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Colin James Watling - Kessingland, Suffolk.

Quite mild this morning, looking out of my open bedroom window with my 20x60 Russian mounted binoculars at the reappearances from behind the dark limb of the Moon (which was earthshine lit and I could see some of the seas or Maria in the Brownish yellow colour of it) of some of the stars of the large open star cluster-the Pleiades (M45). The sky was reasonably clear and with a gentle cooling breeze as well as a bit of peace and quiet to do my observing. I think Magnitude +4 stars could just be picked out with the naked eye and seeing conditions were quite good. I did some timings of the re-appearances and this is what I got: (all times are BST)

Eletctra reappeared at 01:48:05 sec
Celaeno reappeared at 01:57:38 sec
Taygeta reappeared at 02:08:10 sec
Maia reappeared at 02:22:53 sec
Asterope reappeared at 02:24.44 sec

A good 40 Minutes or so of observing done and I enjoyed it very much. I wish things like this took place more frequently —lovely and peaceful.

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Mell Jeffrey - Norton on Derwent, North Yorkshire

Hopefully below should be a table with the timings of last nights occultation of the Pleiades. All timings are in UT (apart from clock which is in BST).I used an 8" with a 15mm eyepiece giving a magnification of X67. All observations where done at home in the dome with a laptop showing LOW for company!! Timing was done using a Hi Gear stopwatch which was stopped against a radio controlled clock which was reset at 00:00UT. A PE of 00.43 seconds was used even for the 2 slower reaction time observations. I encountered problems with the stopwatch, which were down to user error!!!

There was some cloud about, but this didn't affect the observation, but a nearby streetlight cast an orangey glow for the first few reappearances. The seeing appeared to be very good when viewing without the telescope, but the moon appeared to have a "heat shimmer" when view through the telescope, the stars barely "twinkled".

All in all I had an excellent evenings viewing, despite my own errors! — but lessons have been learned

DB Electra = 00:08:04.63
DB Taygeta = 00:27:14.98 (slower reaction time, timing not quiet correct)
DB Maia = 00:31:41.79
RD V624 Tauri = 00:33:32.00 (slower reaction time again, timing not quiet correct)
RD Electra = !! Missed it!!
RD Celaeno = 01:00:27.70
RD ZX4826 = 01:06:24.85
RD Taygeta = 01:09:42.91
RD ZX4840 = 01:19:50.85
RD ZX4845 = !! Almost with ZX4840..not ready, so no timing!!
RD ZX4871 = !! Not timed..human error with stopwatch!!
RD ZX4867 = 00:10.46 seconds after ZX4871 (PE not applied)
RD Maia = 01:25:26.66
RD Asterope = 01:25:27.51 (split timing with Maia, PE applied)

All timings are in UT and a PE of 00.43 Seconds applied unless stated.

All observations made with and 8" Dobsonian mounted reflector using a 15mm eyepiece giving a magnification of X67. Telescope mounted in a dome.

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Martyn Filsak - Stourbridge, Worcestershire

Here are some timings for the occultation on 7 August. One possible problem though: I calibrated my stopwatch using the clock on BBC Teletext. I now suspect that this may not be accurate. In fact, it seems to differ from the clock on ITV Teletext by a variable amount of up to 5 seconds. I'm not sure how to get the Speaking Clock these days, as I haven't phoned it for at least 25 years, but will try to find out. Unfortunately then, the following timings could be plus or minus five seconds or more, but I will attempt to get it right next time.

Location: Stourbridge, Latitude N 52° 27' 03" and Long W 002° 07' 27".

All times U.T.

Emersion times:

Electra: 00:49:28
Celaeno: 00:57:55
Taygeta: 01:07:12
Maia: 01:22:41
Asterope: 1:23:00 (ESTIMATED: came sooner than I expected and I missed it).

This was possibly my clearest ever view of the Moon. The seeing must have been exceptional. I could clearly see irregularities in the profile of the illuminated limb, including a noticeable valley on the SW limb about 30 degrees from the South Pole. Also I saw a bright ray crater, and near it something reminiscent of the Tiger Stripes on Enceladus. Sorry I don't know the Moon well enough (yet, but I'm working on it) to identify these features.

There was a mystery event at about 01:02:28, which other observers in the same region may have seen. I only caught a glimpse of this and could not see the entire track. My immediate reaction was that I was seeing a bright satellite such as the ISS, but soon realised that it moved too fast for this. I think it was a meteor, but slow compared to most meteors I see, though I'm perhaps judging this against the many Perseids that I have seen, which are swift. It was about mag -1 to -2, yellowish, a moving point of light, which I observed for maybe a second, moving in an easterly direction through Cetus. Position and direction of travel would be consistent with a delta Aquarid meteor.

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Dave, Oxfordshire

The actual occultation of the Pleiades was too low to see this morning (due to houses), but I got this shot just after the occultation at 3ish, before going to bed.

This is an interesting shot taken by Dave, because on the right of the image he has captured Mars which was several degrees away from the moon and Pleiades at the time

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