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This page is intended to provide a brief summary of observational attempts for certain important events only and all successful attempts. Full details of all events are published in the Section's Circulars.
(529) Preziosa - 2000 October 1Occultation of TYC 7459 02015 by (529) Preziosa - 2000 October 1:
SUMMARY:Jeff Byron, Epping (Sydney), New South Wales:
Despite strong winds, high level cirrus and the light pollution from the closing ceremony of the Olympic Games occuring only 8km away, Jeff Byron has successfully made the following observations:
Disappearance At : 11:21:25.8 UT (P.E. 0.7 sec applied)
Reappearance At : 11:21:31.1 UT (P.E. 0.4 sec applied)
The duration of 5.3 seconds is close to the predicted maximum of 5.9 seconds. Without any further observations, it is probable that Jeff has observed from close to the centre line of the path.
"This event "clashed" with the Closing Ceremony of the Olympic Games being held here, so it may not have been observed by many others. (I'll watch a video of the ceremony some time from a tape a neighbour recorded for me.) I had planned to use my own VCR to take a video of this occultation, as the star should have been bright enough for this, but as it was, I could only detect one star in the area with the video camera on the telescope so was not certain that it was the "right" one. I therefore took the "safe" path and observed with my own eyeball and at least that way got a definite result. Note that although conditions were far from ideal, the star was bright enough for there to have been absolutely no doubt about this occultation. This is my fourth definite positive result . Previous ones were 198 Ampella (8/9/91); 804 Hispania (5/5/92); 532 Herculina (26/3/97)."
Congratulations Jeff !!
Ross Dickie, Gore, New Zealand
An additional observation report has been received from Ross Dickie in Gore on the South Island of New Zealand - 11:25:33 - 11:32:24 UT. The Olympic significance of this event wasn't lost on Ross ..... "But nevertheless as you know, four minutes before I began monitoring, Jeff Byron successfully observed the occultation by Preziosa, which happens to coincide with the closing ceremony of the Games, right into his own Olympic city of Sydney ! That would have to be the world's first ever observed MP occultation from within an Olympic host city during an Olympic Games, even though the Olympic Flame has just extinguished, 70 minutes before Jeff's occultation event ! And when will be the next occasion in the Olympic future, that a positive MP occultation be observed within an Olympic host city by some lucky astronomers, during the actual occurrence of an Olympic Games ? These Games can only happens for 16 days (or so) at a time, every two years (Winter or Summer), at only one city in any parts of the world."Occultation of PPM 273610 by (117) Lomia - 2000 August 10:
Andrew Pearce, Nedlands, Western Australia:
Disappearance at: 21:36:25
Reappearance at: 21:36:32
My first observed event and I was fortunate to see the occultation. Unfortunately the timing accuracy was limited to the nearest second as the reception from VNG was very poor which made it difficult to detect the pips on the tape with a sufficient level of confidence to increase the accuracy to 0.1s.
Occultation of HIP 84192 by (164) Eva - 2000 June 17:
SUMMARY:
Positive events were reported from two sites in the South Island of New Zealand.
Clive Rowe, Waddington, Canterbury, NZ:
Disappearance at:11:56:55 +- 2 seconds
Duration: Approx. 1.5 seconds
The sky was bright owing to proximity of full moon but 11 mag stars could be seen. The stopwatch was actuated at what seemed to be a disappearance then stopped after approx. 1.5 seconds BUT was then reset as the star reappeared in case there was another ,extended, disappearance. There wasn't. A few seconds prior to this disappearance, there may have been a dimming of the star but this was possibly due to briefly deteriorating seeing. The star seemed to brighten a few seconds after the reappearance, again this may have been seeing.
Alan Thomas, Clyde, Central Otago, NZ:
Disappearance At : 11:57:05.3 (Slow to note)
Reappearance At : 11:57:11.1
Unfamiliarity with procedure resulted in slow disappearance recording. Reappearance much better. Also did not expect star to vanish but fade. Moon limited our mag limit I expect.
Brian Loader, Darfield, Canterbury, NZ:
No event at Darfield for the Eva event. Larry Field and co observed from the Cashmere area of Chch. They saw no event. At West Melton Doug Inwood reports there was too much wind to open up.
Lionel Hussey, Upper Riccarton, Christchurch, NZ:
I was glued to the eyepiece from 11:48 to 12:02 and 15sec. With a nil result. I am not sure if I was on the right star but had a hell of a job finding it in the wind, closeness of the full moon and the fact that I was
working from Norton with the chart provided in the email not having
any scale on it.
Noel Munford, Palmerston North, NZ:
Last evening we spotted the heavenly duo in gaps between clouds for substantial periods in the time leading up to their predicted meeting. Five minutes prior to occultation cloud then intervened to present a much more dramatic double occultation which lasted a breathtaking 54 mins and 22.16 secs. As I know that you always like to here about positive results as early as possible I can at this stage only offer you a preliminary reduction of our observations which suggest that the minor planet Eva probably has a diameter less than 7.6754 million kilometers.
Dave Girling, Mornington, VIC:
The cloud never ends, 164 Eva was no go for me.
Diana Watson, Whakatane, NZ:
Clouded Out!
Barry Griffiths, Blenheim, NZ:
Skies on Sat/Sun were good in
Marlborough apart from wind gusts and a veil of high cloud in the crucial region. Found the field in my 8" with 3 minutes to spare, but no occultation seen.
Tony Dodson, Wellington, NZ:
I had a fast moving cloud problem including a sort of moonlighty
haze which seemed to blot anything below mag 6.5.
Graham Blow & Owen Moore, Wellington, NZ:
We had fast-moving cloud problems. There were several times around the
predicted time when I saw the star disappear, but I felt reasonably sure
each time it was in cloud... but one can never be certain. Certainly I
would not want to rely on any of my "disappearances".
Occultation of TYC 4956 00835 by (250) Bettina - 2000 May 30:
SUMMARY:
Two chords were observed from Queensland by Charlie Smith (duration 34.6 seconds) and Tamas Zalezsak (27 seconds). See discussion below for a preliminary analysis.
The observed track is approximately one track width from the updated prediction.
[View the Updated Prediction]Charlie Smith, Woodridge, QLD:
Disappearance At : 12:30:20.7 +/- 0.1 sec (P.E. 0.6 sec applied)
Reappearance At : 12:30:55.3 +/- 0.1 sec (P.E. 0.4 sec applied)
There were no clouds. Transparency and seeing were not the best, but the star was easily and steadily seen. Asteroid was sighted at 11:07 with difficulty, when it was already pretty close to the N.East of the star. It was not seen during the observation proper, except during the occultation, so no merge or separation was seen. During the occultation the asteroid was seen intermittently due to the seeing conditions - it seemed to me that it was probably fainter than predicted. I have no doubts regarding the times I have given for disappearance and reappearance, (even though this gives a duration of 9.8 secs. more then the predicted maximum.)
Tamás Zalezsák, Chapel Hill, QLD:
Disappearance At : 12:30:24 +/- 1.0 sec (estimated P.E. 1.0 sec)
Reappearance At : 12:30:51 +/- 1.0 sec (estimated P.E. 0.5 sec)
Perfect long occultation. The asteroid was perfectly seen
during the occultation.
Peter Nelson, Ellinbank, VIC:
Sorry, solid overcast and rain for Bettina and Palatia last night.
Jeff Byron, Sydney, NSW:
Last night as event time approached:
10:00 UT Reasonably clear (some light haze)
11:45 UT Increasing cloud
12:30 UT Extensive cloud cover in area of interest.
Plotting the observed chords against a circular outline of diameter 131 km produces a fit which is not exact, but which is certainly within the bounds of error. Click for 131 x 131 km plot.
Plotting the chords against an ellipse of 85 x 131 km, with a pole rotation of 34 degrees, produces an initially more pleasing result. However, with only two chords available it is unlikely to be possible to unambiguously distinguish between a circular and elliptical result. One additional chord, well-separated from the other two, would have been sufficient to make this distinction. Click for 85 x 131 km plot.
NOTE: The information on this web page is a very cursory initial analysis only. A full analysis may indicate a substantially different result. Publication of the complete results will take place in due course.
Occultation of HIP 80125 by (445) Edna - 2000 May 28:
SUMMARY:
A single chord was observed by Brian Loader in Christchurch (duration
3.5 seconds). The observed track is within two track widths of the
updated prediction.
Brian Loader, Christchurch, NZ:
Disappearance At: 11:14:33.8 (1.2 seconds PE allowed for - slow reaction +/- 0.4s)
Reappearance At: 11:14:37.3 (0.4 seconds PE allowed for - good reaction +/- 0.1 s)
Good sharp event. Plenty of other stars visible in field to check by. Best MP event I
have seen.
Bob Evans, Invercargill, NZ:
Well, the Edna occultation was nicely timed, a good position in the
sky and a decent mag drop. So, of course we were completely clouded
out. It did stop raining for awhile. :-(
Noel Munford, Palmerston North, NZ:
Well surprise surprise, it was clear here last evening. I guess that was
because Murphy had checked out the web site and determined that the path
was now elsewhere. In spite of that I still had a look from 11.09 to
11.21UT. Saw absolutely nothing which I guess is still something.
Graham Blow, Wellington, NZ:
Clear. No occultation. Clouds covered the field 5 minutes after I finished
observing.
Charlie Smith, Woodridge, QLD:
Star was clearly seen at all times, no events were observed.
Occultation of HIP 75185 by (5) Astraea - 2000 May 22:
SUMMARY:
Two chords were observed by Albert Brakel (near Micaligo, ACT; Duration
6.4 seconds) and Robert Price (near Wodonga, VIC; duration ~15 seconds). In
addition a negative observation by Vello Tabur (Canberra, ACT) may provide
a constraining chord to the event. See discussion below for a preliminary analysis.
The observed occultation is in very good agreement with the path predicted by USNO and Hipparcos astrometry.
[View the Updated Prediction]Albert Brakel, Micaligo, ACT:
Disappearance At : 17:52:49.1 (Sudden)
Reappearance At : 17:52:55.5 (Sudden)
At first disappearance was complete, probably because I had been staring
at the star so intently that it affected my night vision somewhat. Seconds
later my vision had recovered enough to see the asteroid very dimly, but
it was significantly fainter than a mag. 10.0 star 4.6' to the N.
I travelled south from Canberra to increase the chances of seeing a positive event, and to get some distance away from other observers who were going to try from Canberra. I chose a place 8.8 km south of the town of Michelago, near a locality called Micaligo, so I would be about 20 km north of the chord of any possible observer in the Albury-Wodgonga area.
It's just as well I travelled out, because when I got back to Canberra an hour later, fog had closed in around the city. If I had tried to observe from home, I probably would have failed. I know that Eric Pozza made the effort to try to observe from Red Hill in Canberra, but found himself fogged in.
I am very impressed with how close the time of the event was to the astrometric prediction. This is my first positive event in about 110 monitorings since 1993. There have also been about 100 attempts where observations were prevented by clouds, rain, moonlight, twilight, trees, fog, smoke, or car headlights. I think I've earned this one.
Robert Price, Bethanga, VIC:
(Reported by Jim Blanksby)
Disappearance was at 17:52:59 UT and, with less confidence, the
Reappearance was at 17:53:14 UT.
Vello Tabur, Canberra, ACT:
It was very cold with an extensive frost cover but the sky was clear. The
fog had not rolled in yet when I set up. Having found the star and asteroid,
I mucked around with the SW radio for about half an hour trying to find a
fequency with decent reception (without luck). I finally gave up at 17:51
and started observing using a stopwatch. Unfortunately over the next 30
seconds or so, the eyepiece fogged up! It was too close to the predicted
time of occn. and I could just see the star, so I didn't swap eyepieces.
Unfortunately it got worse and although I never lost sight of the star,
the other fainter field stars disappeared. I watched until around 17:56
without seeing any sudden changes in brightness, although I'd class my
observations as "dodgey" at best. In several years of "cold climate"
comet hunting, I've only had a fogged up eyepiece once before. What a time
to set a new record :-(
John Howard, Downer, ACT:
Clouded out.
Jim Blanksby, Wandin, VIC:
Clouded out.
Joe Grida, Unley, SA:
Did not see occultation, although star & asteroid did merge. Did not see
a brightness drop. Astrea passed South of star.
Peter Nelson, Ellinbank, VIC:
Cloud at 17:30 UT, so no observations.
Peter Skilton, Frankston Heights, VIC:
No luck here locally for me, being totally overcast. However, I did notice
what appeared to be clear sky on my extreme North Western horizon.
Therefore observers at or North of Melbourne could potentially have had an
observable event.
Dave Girling, Mornington, VIC:
Just a note for the occultation, Astraea May 22 !7:53ut. Once again i got up
and found it was cloudy as per normal. It is a bad time of the year thow!
Michael Mattiazzo, Wallaroo, SA:
Unfortunately, I erred in remembering the exact time that the occultation
was due from my site and ended my observing session prematurely. A lesson to
be learned.
NOTE: The information on this web page is a very cursory initial analysis only. A full analysis may indicate a substantially different result. Publication of the complete results will take place in due course.
Occultation of TYC 6182 00371 by (349) Dembowska - 2000 May 17:
SUMMARY:
Diana Watson's observed duration of 11.6 seconds is a little longer than
the expected maximum duration of 10.7 seconds, but Diana is confident that
she saw the event. The observed track is in very good agreement with the
track predicted by the astrometric update. With a track across Whakatane,
NZ, observers near Melbourne would have only been a few tens of kilometres
outside the actual occultation shadow.
Diana Watson, Whakatane, NZ:
Merged: 14:23:00
Disappearance: 14:28:59:6 UT (Not highly accurate: I was surprised. Up to 2 seconds slow).
Reappearance, 14:29:11:2 UT (About 0.5 second PE).
Separated: 14:38:00
Brian Loader, Christchurch, NZ:
Clear... up until 9 minutes before the event.
Noel Munford, Palmerston North, NZ:
Our sky was clear, but we had a lot of moisture in the air and the moonlight
flooded the area. Couldn't hardly see 7th mag stars, so again I report a no
chance observation.
Alex Liu, Exmouth, WA:
Although the minor planet was clearly seen, no event was observed. It
passed south of the star, although still totally within the star's airy
disk.
Charlie Smith, Brisbane, QLD:
Star was clearly seen at all times, no events were observed.
Peter Skilton, Frankston Heights, VIC:
Last night's MP event was too difficult with my 15cm instrument in the
prevailing moonlight and aerosol (pre-foggy) conditions. It was very cool.
Dave Girling, Mornington, VIC:
Cloud.
Albert Brakel, Downer, ACT:
Star and asteroid formed one merged image at the start and throughout most
of the observation. When the images separated near the end of the
observation, the asteroid was near the limit of direct vision. Had an
occultation occurred, the drop in magnitude would have been unmistakable.
Roger Giller, Berwick, VIC:
I got home from the ASF meeting in what should have been plenty of time,
set up the 8" and after a long search found the field, including the star
AND Dembowska about 1400 UT. I started the drive and went to get the
timing gear. By the time I had that set up the star had drifted out of the
field. I had to go back to Beta Sco and start hopping again by which time
it was too late.
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