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This page provides an overview of all events observed during the year where a positive occultation was recorded. Full details of other observational attempts are published in the Section's Circulars.
(1428) Mombasa - 2004 Dec 28Occultation of 2UCAC 34226229 by (1428) Mombasa - 2004 Dec 28:
A 4.6 second occultation was observed by Peter Anderson from Brsibane, Queensland.
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Observational Data:
Observer's Name : Peter Anderson
Aperture (cm) : 41
Focal length (cm) : 245
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : X 98 (25mm eyepiece)
Observing site name : Taylor Range Observatory
Longitude (East +ve) : 152 56 01.4580
Latitude (South -ve) : -27 27 47.5562
Deflection of the Vertical Meridian: -5.271 Prime Vertical: 3.189
Please note that this astronomical position has been determined by Qld Dept of Natural Resources
and is consistent with the Geodetic Datum of Australia (GDA94). The physical position of the
station has not shifted since establishment in 1980. (To find the position of the observatory
under various datums, refer to my website www.uq.net.au/~zzpeande and reference the article
'The problem of Position' under 'Articles'.)
Height above Sea level (metres) : 176.3
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Bright 97% Moon
Time Source (e.g. WWVH, VNG) : WWVH
Recording method (e.g. tape) : Stopwatches and tape recorder
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 12.5 to 13.0
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 12hrs 37min 00sec
Disappearance At : 12hrs 39min 16.7sec 0.53sec +/- 0.15sec
Reappearance At : 12hrs 39min 21.3sec 0.43sec +/- 0.15sec
Stopped Observing : 12hrs 42min 00sec
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : Yes - see above
If YES, state value : See above
ADDITIONAL COMMENTS: The star was very faint. My left eye which I habitually favour
yields a lower contrast and fainter yellowed image (since I am an old bugger and the
lens has yellowed.) I had a cataract operation on my right eye last year and it now
yields a bright contrasty image but is uncomfortable at the eyepiece. I used my right
eye because I could barely hold the image of the star with the left. At 12hrs 09min 08sec
for about 1 second I lost sight of the image, but I believe that this was spurious.
The event itself was definite even though the star was near the limit of visibility.
A miss was also recorded by John Broughton as follows:
Observer's Name : John Broughton
Aperture (cm) : 50.1
Focal length (cm) : 185
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : CCD drift-scan, 5.5 pixels per second
Observing site name : Reedy Creek, Gold Coast
Longitude (East +ve) : +153 23' 49"
Latitude (South -ve) : -28 06' 36"
Height above Sealevel (metres) : 66
Geodetic Datum (e.g.WDD84,NZ1949): AGD66
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Time Source (e.g. WWV, VNG) : WWVH.
Recording method (e.g. tape) : Tape.
Could you see the Asteroid? : Only combined light monitored.
Approx. Limiting Magnitude : 14
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 12:38:41.2
Stopped Observing : 12:39:42.0
ADDITIONAL COMMENTS: CCD sidereal drift observation using methods described
here: http://www.users.bigpond.com/reedycrk/driftscantiming.htm
Definitely no occultation during the period of observation.
Occultation of TYC 1895-00724-1 by (779) Nina - 2004 Dec 24:
A 1.9 second occultation was observed by David Herald from Beacon, WA.
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Observational Data:
Observer's Name : David Herald
Aperture (cm) : 12.5
Focal length (cm) : 190
Type (e.g. SCT; Newtonian) : Maksutov [ETX-125]
Magnification : 73
Observing site name : Beacon, WA
Longitude (DD MM SS ; East +ve) : 117 52 04.1
Latitude (DD MM SS ; South -ve) : -30 26 59.5
Height above Sealevel (metres) : 382
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : GPS
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair
Time Source (e.g. WWVH, GPS) : GPS
Recording method (e.g. tape) : Stopwatch
Could you see the Asteroid? : Well before the event - yes (just)
Approx. Limiting Magnitude : 12.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Observing : 18 33 00
Disappearance At : 18 33 43.0
Reappearance At : 18 33 44.9
Stopped Observing : 18 34 00
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : Yes
If YES, state value : 0.4.
ADDITIONAL COMMENTS:
1. Time base was from a GPS receiver without a 1pps output from the GPS
engine. The reported times also include an additional subtraction
of 1.0 secs to allow for the time delay in the GPS receiver
displaying the time.
2. Observation was dependent upon averted vision. I cannot exclude the
possibility that the event was caused by atmospherics rather than an
occultation. I'm about 70% confident that it was an occultation.
Uncertainty too great to use the observation to report a position of
the asteroid.
Occultation of TYC 0141-00053-1 by (238) Hypatia - 2004 Nov 22:
A 9.84 sec occultation was captured on video by David Herald in Kambah, ACT. Albert Brakel, observing from Downer ACT was clouded out at the critical time, but reports that for the 2 minutes he could see the star (14:35:10 - 14:37:11) there were no occultations by satellites.
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Observational Data:
Observer's Name : David Herald
Aperture (cm) : 36
Focal length (cm) : 360
Type (e.g. SCT; Newtonian) : SCT
Magnification : -
Observing site name : Kambah
Longitude (East +ve) : 149 03 49.0
Latitude (South -ve) : -35 23 49.3
Height above Sealevel (metres) : 583
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : -
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair
Time Source (e.g. WWV, GPS) : WWV
Recording method (e.g. tape) : Video
Could you see the Asteroid? : -
Approx. Limiting Magnitude : -
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Disappearance At : 14 41 11.93 .03
Reappearance At : 14 41 21.77 .03
Event Duration : 9.84 sec
ADDITIONAL COMMENTS:
I have now recorded my first asteroidal with my 14" + low-light video camera. The relatively short duration
suggests the path was moved northwards by close to 1 sigma - such that observers in Melbourne would have
likely got a miss. Also the mid-time (of 14h 41m 17s) suggests the shadow was about 0.5 sigma behind prediction.
Occultation of TYC 1264-00053-1 by (80) Sappho - 2004 Nov 17:
An occultation of 6.4 seconds duration was recorded by Diana Watson in Whakatane, New Zealand.
The following additional observers reported cloud at their locations: Andy Dodson (New Plymouth); Sharon Suter (New Plymouth); Tom Whelan (Cape Egmont); Rod Austin (New plymouth); Gary Powell (Tauranga).
View the Updated Prediction
Observational Data:
Observer's Name : Diana Watson
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtonian) : Celestron 8
Magnification : 115 times
Observing site name : Whakatane
Longitude (DD MM SS ; East +ve) : 176 51 50.7
Latitude (DD MM SS ; South -ve) : -37 55 18.5
Height above Sealevel (metres) : 2.8 metres
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : -
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Good
Other Conditions : Lot of cloud around, but Orion and Taurus area clear, though moisture
disturbance seen in telescope.
Time Source (e.g. WWVH, GPS) : WWVH
Recording method (e.g. tape) : tape recorder
Could you see the Asteroid? : Yes
Approx. Limiting Magnitude : 12
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 15:35:00.0
Star and Object Merged : 15:35:00.0 by this time
Disappearance At : 15:43:13.2 slow poss. 1 sec.
Reappearance At : 15:43:19.6 0.4 full brightness.
Star and Object Separated : 15:53:00.0 by this time.
Stopped Observing : 15:50:00.0
Duration : 6.4 sec
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : NO
If YES, state value : -
ADDITIONAL COMMENTS: Slow fading of the star, timed when all dimmed, may have been a bit slow at
doing so. Felt that the planet passed slightly south of the star as on returning, again slowly, had
the impression of a brighter top, NE, and a dark, wiggley(!)line which disappeared when full brightness
returned, and my timing of the event. Could sketch it if I was reporting by snail mail!
ADDITIONAL COMMENTS 20 Nov 04:
I would estimate it took about 2 seconds to dim, and about 3 secs to come back to brightness again. I had time to think, as it was happening.
Occultation of TYC 1197-00821-1 by (81) Terpsichore - 2004 Nov 17:
A 23.2 second occultation was timed photoelectrically by Alan Gilmore at Mt John Observatory. The predicted maximum duration was 23.4 seconds and Mt John was expected to be on the edge of the path. The observed event indicates that the path moved northwards by about one track width. Ross Dickie advises that it was cloudy in northern Southland.
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Observational Data:
Observer's Name : Alan Gilmore
Aperture (cm) : 60 cm
Focal length (cm) : 960 cm
Type (e.g. SCT; Newtonian) : Cassegrain
Magnification : n/a
Observing site name : Mt John Observatory
Longitude (DD MM SS ; East +ve) : 170d 27' 51" (estimated)
Latitude (DD MM SS ; South -ve) : -43d 59' 09"
Height above Sea-level (metres) : 1035 (estimated)
Geodetic Datum (e.g.WGS84,NZ1949): GRS80 ellipsoid
Height Datum (if known) : -
[The above position estimates are from the location of the GPS pillar east of
the OC telescope. I will measure the OC-pillar distances for an accurate
location; but not soon. The GPS pillar location is:
Lat : -43d 59' 08.5361"
Lon : 170d 27' 53.7891"
Hgt : 1043.639m
Epoch : October 2004.
Source : Dr Paul Denys, Department of Surveying, University of Otago.]
Sky Transparency (Delete two) : Fair (Some thin Ac cloud bands nearby)
Star Image Stability : Poor (Image diameter ~10")
Other Conditions : region low ~12 degrees altitude.
Time Source (e.g. WWVH, GPS) : Computer clock started by keypress from GPS display
Recording method (e.g. tape) : Photometer to computer memory
Could you see the Asteroid? : No. Seeing very poor
Approx. Limiting Magnitude : 14
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 13:33
Disappearance At : 13:39:52.2
Reappearance At : 13:40:15.4
Stopped Observing :~13:43:00
Duration : 23.2 sec
Accuracy, ±0.5 s for absolute time
Interval accurate to ± 0.2 s. See appended log.
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : n/a
ADDITIONAL COMMENTS: Interval well timed. Absolute time probably accurate to
±0.5 sec. I restarted the computer's clock on our GPS readout. There were no
time signals to get any sort of check calibration.
Mt John Photoelectric Data:
Occultation of HIP 111034 by (921) Jovita - 2004 Sep 29:
An occultation of indeterminate duration was seen by Frank Adamson in Toowoomba, Queensland.
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Observational Data:
Observer's Name : Frank Adamson
Aperture (cm) : 20.32 cm
Type (e.g. SCT; Newtonian) : SCT
Observing site name : Briddas Garth
Longitude (DD MM SS ; East +ve) : 151 53 04 East
Latitude (DD MM SS ; South -ve) : 27 33 24 South
Height above Sealevel (metres) : 630 metres
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : Sea level
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): Full Moon close by
Time Source (e.g. WWVH, GPS) : GPS
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 12
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Disappearance At : While set up I forgot to start/stop in my excitement
Estimated Closest Approach : this was my first observed asteroid occultation!
ADDITIONAL COMMENTS:
Attach my first real asteroid occultation report, while I had all the timing
gear set up and running, in my excitement I forgot to operate it!
Occultation of TYC 0019-00633-1 by (151) Abundantia - 2004 Sep 6:
Please refer to the separate Abundantia results page.
Occultation of 5229-01169-1 by (514) Armida - 2004 Sep 4:
Please refer to the separate Armida results page.
Occultation of 2UCAC 26349643 by (60) Echo - 2004 Aug 28:
A 5.21 second occultation was recorded by John Broughton from Reedy Creek, Qld, using the CCD drift-scan technique.
View the Updated Prediction
Observational Data:
Observer's Name : John Broughton
Aperture (cm) : 50.1
Focal length (cm) : 185
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : CCD drift-scan, 5.4 pixels per second
Observing site name : Reedy Creek, Gold Coast
Longitude (East +ve) : +153 23' 49"
Latitude (South -ve) : -28 06' 36"
Height above Sealevel (metres) : 66
Geodetic Datum (e.g.WDD84,NZ1949): AGD66
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Full moon 15 degrees from target
Time Source (e.g. WWV, VNG) : WWVH.
Recording method (e.g. tape) : Tape.
Could you see the Asteroid? : Only combined light monitored.
Approx. Limiting Magnitude : 13.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 12:20:00.29 N.A. 0.01
Disappearance At : 12:20:19.96 N.A. 0.12
Reappearance At : 12:20:25.17 N.A. 0.12
Stopped Observing : 12:20:50.71 N.A. 0.01
Duration : 5.21
ADDITIONAL COMMENTS: CCD sidereal drift observation using timing methods
as described here: http://occsec.wellington.net.nz/videotime/ccdtiming.htm
When last used 2 nights before, the telescope was pointed within
1 sidereal second of the calculated RA offset coordinate.
A powerful thunderstorm 3 hours ahead of occultation was followed by a
deck of altocumulus overlaid to my dismay by a layer of altostratus.
With the full moon only 15 degrees from the target star, such haze if it
persisted would ruin any chance of success.
I had succeeded once before under seemingly hopeless circumstances so for
occultations with high probability of occurring I always go through the
motions just in case there is a last minute improvement in the weather.
The dome shutters were positioned to minimize entrance of moonlight
as well as shade the secondary mirror holder. 15 minutes before the
occultation the haze had cleared and a clearer section of altocumulus was
approaching. At T-10 minutes I started the delayed exposure of 50 seconds.
This was kept short to minimize the chance a transiting cloud can saturate
the image with reflected moonlight. All I had to do then was start taping
my time signal/camera shutter events and visually monitor a separate
digital timer to obtain manual times independantly.
The presence of the full moon makes this event equivalent to a 13th
magnitude occultation in a dark sky but the image clearly shows the
familiar gap near the middle of the trail and the other trails indicate
an absence of cloud during the exposure. Analysis revealed mid-occultation
occurred within 1 second of Steve Preston's prediction!
Occultation of TYC 8421-01308-1 by (705) Erminia - 2004 Aug 23:
A 6.0 second occultation was recorded by Brian Loader at Darfield, New Zealand.
Observational Data:
Observer's Name : Brian Loader
Aperture (cm) : 25.4
Focal length (cm) : 250
Type (e.g. SCT; Newtonian) : SCT
Magnification : n/a
Observing site name : Darfield
Longitude (DD MM SS ; East +ve) : +172° 06' 24.4" E
Latitude (DD MM SS ; South -ve) : -43° 28' 52.9" S
Height above Sealevel (metres) : 210
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): 48% Moon
TIMINGS: (PLEASE REPORT IN UNIVERSAL TIME)
Time Source (e.g. WWVH, GPS) : GPS/KIWI
Recording method (e.g. tape) : VIDEO
Could you see the Asteroid? : no
Approx. Limiting Magnitude : see notes
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 07:06
Disappearance At : 07:11:06.5 n/a +/-0.1
Reappearance At : 07:11:12.5 n/a +/-0.1
Stopped Observing : 07:14
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : n/a
ADDITIONAL NOTES:
The path was predicted to go over Mt John, with Darfield a good half width north
of the predicted track and about 1.5 sigma north of the edge. In fact there was
a 6 second event here. Maximum expected duration 9.6 seconds.
Despite the 11.9 magnitude the image was reasonably easy to see by video. The
star is very red, with a B-V getting on for 2. A less red star would probably
not have been visible by the video at this magnitude. Also the seeing was good.
Although clearly visible there was no chance of setting the disappearance by stepping
through, so had to take of the time using a stop watch. I suppose it could be said
I should report a PE for doing this, however I am reasonably confident of the accuracy
of the times.
Occultation of TYC 5241-00829-1 by (684) Hildburg - 2004 Aug 23:
A 0.7 second occultation was recorded by Dave Burton near Longreach, Qld. This was an especially good result given the narrowness of the predicted track and its low certainty.
Observational Data:
Observer's Name : Dave Burton
Aperture (cm) : 20
Focal length (cm) : 100
Type (e.g. SCT; Newtonian) : Newt.
Magnification : 40
Observing site name : 3 km S Longreach
Longitude (DD MM SS ; East +ve) : 144 14 51.5
Latitude (DD MM SS ; South -ve) : -23 28 15
Height above Sealevel (metres) : 179
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : Satellite
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions: Sky Clear, Wind <5 Kts NE, Town 3 km N
Time Source (e.g. WWVH, GPS) : WWVH
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 10.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 09:42:00
Disappearance At : 09:48:49.4
Reappearance At : 09:48:50.1
Stopped Observing : 09:50:00
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No
Occultation of TYC 6977-00259-1 by (199) Byblis - 2004 Aug 6:
A 4.9 second occultation was recorded by Peter Anderson in Brisbane, Qld.
Observational Data:
Observer's Name : Peter Anderson
Aperture (cm) : 41cm
Focal length (cm) : F6
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : X198
Observing site name : Taylor Range Observatory
Longitude (East +ve) : 152deg 55' 54.04"
Latitude (South -ve) : -27deg 27' 47.96"
Height above Sealevel (metres) : 176.3metres
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair
Time Source (e.g. WWV, VNG) : WWVH
Recording method (e.g. tape) : TAPE
Could you see the Asteroid? : Didn't start early enough to follow it but saw it easily
during the 4.9 seconds of occultation.
Approx. Limiting Magnitude : 14.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 14 33 00.0
Disappearance At : 14 34 30.2 0.8 second +0.1sec -0.3sec beginning of fade of 0.25 sec
Reappearance At : 14 34 35.1 0.3second +/-0.15sec begin return to full brightness 0.2sec long
Stopped Observing : 14 36 00.0
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : Yes - as stated
ADDITIONAL COMMENTS:
My second tape recorder behaved itself. I was tired and didn't trigger the stopwatches, but
I am comfortable with the taped comments. The event was very obvious and easily observed once
I found the star. (The star maps on the website leave much to be desired.)
It is quite exciting to see two events within three hours of each other.
Occultation of TYC 4965-00197-1 by (566) Stereoskopia - 2004 Aug 6:
An definite occultation of indeterminate duration was recorded by Peter Anderson in Brisbane, Qld.
Observational Data:
Observer's Name : Peter Anderson
Aperture (cm) : 41cm
Focal length (cm) : F6
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : X198
Observing site name : Taylor Range Observatory
Longitude (East +ve) : 152deg 55' 54.04"
Latitude (South -ve) : -27deg 27' 47.96"
Height above Sealevel (metres) : 176.3metres
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Very Poor
Other Conditions:
(Wind, Clouds, Lights, etc.): Gusty westerlies
Time Source (e.g. WWV, VNG) : WWVH
Recording method (e.g. tape) : Tape - or so I thought
Could you see the Asteroid? : NO
Approx. Limiting Magnitude : 12.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 11 58 20.0
Disappearance At : 11 59 10 ??? see comments below
Reappearance At : 11 59 20 ???
Stopped Observing : 12 00 45.0
ADDITIONAL COMMENTS:
Gusty westerlies, very low altitude, and faint blobby images. ID certain. I kept the
monitoring short so I didn't tire as I concentrated on the faint images. It was so
difficult concentrating that I relied on the tape comments rather than stopwatches.
The tape recorder, (unbeknown to me) failed at the outset and chewed up the tape.
The visibility of the merged image of star and asteroid was 'coming and going'. There
definitely was an event because the image was not seen for about 10 seconds in the
11hrs 59min 10sec to 11hrs 59min 20sec area and again I did not see it for about 5
seconds or so around 11hrs 59min 35secs. Clearly much of this was the atrocious seeing,
with the wind and low altitude. With the tape chewed up and no stopwatch, this is all
I can report (from my memory) Even if I had an accurate record the accuracy would be
very low.
Occultation of 2UCAC20927152 by (33) Polyhymnia - 2004 July 24:
A 10.9 second occultation was recorded by Brian Loader at Darfield, New Zealand, using video.
Observational Data:
Observer's Name : Brian Loader
Aperture (cm) : 25.4
Focal length (cm) : 250
Type (e.g. SCT; Newtonian) : SCT
Magnification : N/A
Observing site name : Darfield
Longitude (DD MM SS ; East +ve) : +172° 06' 24.4" E
Latitude (DD MM SS ; South -ve) : -43° 28' 52.9" S
Height above Sealevel (metres) : 210
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good/Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): nil
Time Source (e.g. WWVH, GPS) : GPS/KIWI
Recording method (e.g. tape) : VIDEO
Could you see the Asteroid? : Yes on monitor
Approx. Limiting Magnitude : 11.8 on monitor
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Observing : 07:47
Star and Object Merged : c 07:51
Disappearance At : 07:54:36.4 N/A +/- 0.1 sec
Reappearance At : 07:54:47.3 N/A +/- 0.1 sec
Star and Object Separated : c 07:58
Stopped Observing : 08:00
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : N/A
ADDITIONAL COMMENTS:
Star magnitude 11.7, MP magnitude 11.3, Combined 10.7, change in magnitude at occultation 0.6
Both star and MP were visible on the monitor, the combined image brightening near the time of
the event. Although the change in magnitude was only ca 0.6, the event was quite easy to detect
on the video monitor, especially as the image almost disappeared. Times had to be taken off
the video by numerous runs using a stop watch. The times are reasonably reliable, although the
reappearance was a bit fuzzy, probably a seeing effect.
Duration of occultation 10.9s. Maximum expected duration 11.8s. Observing site was just over
one-quarter of the way in from the predicted edge of the path to its centre line. Length of the
observed event suggests I could have been a little deeper into the track, assuming a circular outline.
Occultation of HIP 96545 by (61) Danae - 2004 July 19:
Although a very difficult event, an occultation was seen by Steve Kerr from Rockhampton, Qld.
Observational Data:
Observer's Name : Stephen Kerr
Aperture (cm) : 25
Focal length (cm) : 150
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : 50
Observing site name : Glenlee
Longitude (DD MM SS ; East +ve) : +150 30' 01.4"
Latitude (DD MM SS ; South -ve) : -23 16' 10.1"
Height above Sealevel (metres) : 50
Geodetic Datum (e.g.WGS84,NZ1949): WGS 1984
Height Datum (if known) : AHD
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Time Source (e.g. WWVH, GPS) : WWVH
Recording method (e.g. tape) : Stopwatch + Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 12.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 16:27:00.0
Disappearance At : 16:29:59.0 3.0
Reappearance At : 16:30:07.0 2.0
Stopped Observing : 16:34:00.0
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : NO
COMMENTS:
An extremely difficult event to observe due to very low mag drop. Virtually no confidence in the
reported D and R times but reasonably confident that an event happened. This would have been an
easier observations if the star was around Mag 10 rather than 7.5 - if I get this situation again,
I would stop the scope down to around 4".
To do the observation, I compared the star with TYC 7940-01613-1 just to the south at mag = 8.8.
There was a period there where the two stars looked very similar in brightness and these are the
times reported here as D and R. But to be honest, neither the D or R were at all obvious. So I
would suggest that we can say nothing about the chord length of this event - just that there was
one (another job for video :( There is a rule of thumb amongst visual variable star observers that
I know well from personal experience to be true - the human eye is most capable of distinguishing
subtle brightness variations when the star is around 3 mags above the limiting mag. In this case,
it was around 5 mags.
Occultation of TYC 7400-02712-1 by (55) Pandora - 2004 July 09:
A 12.2 second occultation was observed by Gordon Hudson from Pukerua Bay, New Zealand. The updated prediction is available here.
Observers: 1 G. Hudson, Pukerua Bay, NZ 2 G. Blow, Khandallah, NZ 3 T. Butt, Te Horo, NZ
(Plot generated using WinOCCULT. Disappearances on the left, Reappearances on the right. Circle represents the estimated diameter of Pandora of 66 km)
Comments:
The drop in mangitude for this event was only 0.9, making it difficult for visual observers. Gordon Hudson feels sure that he saw the star dip in brightness at the predicted time, but he quotes his reaction time on both the D and R as being about 3 seconds. Gordon's occultation was 12.2 seconds. The predicted duration for a central occultation by this estimated 66 km diameter asteroid was only 6.1 seconds. Because of the difficulty of the event the negative observations of Graham Blow and Terry Butt should not be taken as absolute.
Observational Data:
Observer's Name : Gordon Hudson
Aperture (cm) : 30cm
Focal length (cm) : 300cm
Type (e.g. SCT; Newtonian) : Cassegrain
Magnification : 187x
Observing site name : KPO
Longitude (DD MM SS ; East +ve) : 174°52'54.36"
Latitude (DD MM SS ; South -ve) : 41°s02'27.61"
Height above Sealevel (metres) : 108.5meters
Geodetic Datum (e.g.WGS84,NZ1949): 1949
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Time Source (e.g. WWVH, GPS) : GPS
Recording method (e.g. tape) : Computer & Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 12
| Estimated |
Universal Time | Reaction | Accuracy,Remarks
h m s | Time (sec) |
Started Observing : 12:30:00
Disappearance At : 12:58:9.1
Reappearance At : 12:58:21.3
Stopped Observing : 13:15:00
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No
ADDITIONAL COMMENTS:
I was unable to get an accurate time it was very spurious. The star
appeared to go out but my timing was not accurate and I would estimate a 3
second delay. Also on the reappearance there was probably a 3 second delay
before I could verify that it had reappeared. It was very difficult to see if
the star dimmed however I am sure it almost disappeared. (Averted vision was used).
Observer's Name : Graham Blow
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtonian) : SCT
Magnification : 166
Observing site name : Khandallah
Longitude (DD MM SS ; East +ve) : 174 48 16.0 E
Latitude (DD MM SS ; South -ve) : -41 14 41.62
Height above Sealevel (metres) : 112
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Time Source (e.g. WWVH, GPS) : WWVH
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : > 12
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 12:54
Stopped Observing : 13:01
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No
ADDITIONAL COMMENTS:
As far as I could tell, no event occurred. (Star easily seen with averted vision).
Observer's Name : Terry Butt
Aperture (cm) : 25
Type (e.g. SCT; Newtonian) : SCT
Observing site name : Te Horo, NZ
Longitude (DD MM SS ; East +ve) : 175 07 32.06 E
Latitude (DD MM SS ; South -ve) : -40 48 49.12
Height above Sealevel (metres) : 60
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
ADDITIONAL COMMENTS:
I looked but saw no change or event, but this could be due to my inexperience.
Occultation of TYC 6255-01403-1 by (17) Thetis - 2004 June 28:
A 9.5 second occultation was observed by Dave Burton from Longreach, Qld.
Observational Data:
Observer's Name : Dave Burton
Aperture (cm) : 20
Focal length (cm) : 100
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : x40
Observing site name : Bexley Station
Longitude (DD MM SS ; East +ve) : 144 15 46.3
Latitude (DD MM SS ; South -ve) : -23 11 11.5
Height above Sealevel (metres) : 205
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : GPS
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Sky Clear, Moon Set 1Hr before
Time Source (e.g. WWVH, GPS) : BIMP (Radio station)
Recording method (e.g. tape) : 2 x Stopwatches
Could you see the Asteroid? : Yes, 30 Min before event
Approx. Limiting Magnitude : 12
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 18:01:00
Disappearance At : 18:10:10.85
Reappearance At : 18:10:20.30
Stopped Observing : 18:18:00
Duration : 9.5 sec
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No, direct stopwatch readings given
ADDITIONAL COMMENTS: Slower dimming than I expected, and brightening. This is the first
Occultation I have observered so I have no reference for this comment. The dimming was
clearly evident however. Reappearance was made difficult due to very bright meteor across
field during event causing some dazzling, I may have been slightly late due to this, but
less than 0.5 sec. Watches showed that the local radio pips at 18:00z were accurate to
within reflex errors.
Occultation of HIP 83181 by (287) Nepthys - 2004 Jun 24:
High hopes were held for this event as the star was bright (mag 8.0), the event occurred at a very convenient time in the evening, and the path crossed regions with potentially many observers.
A 6.1 second occultation was observed by Dave Brock at Hangatiki, about half way between Otorohonga and Te Kuiti, indicating that the actual path (shown here) was close to that predicted. Misses were recorded by Gary Beal in Hamilton and John Drummond north of Gisborne while a number of other observers who would have otherwise seen the event were unfortunately clouded out.
The approximate diameter of Nepthys, predicted from IRAS data, is about 67 km. However the negative observations of Beal and Drummond provide a constraint on the axis of the asteroid aligned north-south at the time of the event. If this axis was indeed 67 km then, given the positive occultation of Dave Brock, either Gary Beal should have seen an event of about 5.4 sec duration or John Drummond should have seen an approx. 3.8 second occultation. The fact that neither did so indicates that this axis of Nepthys cannot be greater than 60 km. This is a useful result! The result could have been enhanced by two additional positive observations which would have provided more information about the true orientation of Nepthys at the time.
In the diagram below the one positive and two negative observations are plotted, together with the locations of the observers who were clouded out. The circle is of 60 km diameter, the maximum permissible given the observations.
Nepthys was observed at occultation on two occasions in 2003, but with only a single chord each.
Observers: 1 D. Brock, Hangitiki, NZ 2(M) G. Beal, Hamilton, NZ 3(C) R. Austin, New Plymouth, NZ 4(C) D. Watson, Whakatane, NZ 5 PREDICTED CENTRE LINE 6(C) G. Powell, Ngatira, NZ 7(M) J. Drummond, Loisel's Rd, NZ 8(C) J. Van Ekeren, Te Awamutu, NZ M = Miss C = Cloud
Observational Data:
Observer's Name : Dave Brock
Aperture (cm) : 20cm
Focal length (cm) : 120cm
Type (e.g. SCT; Newtonian) : Newtonian (dob.)
Magnification : 75x
Observing site name : Hangatiki school
Longitude (DD MM SS ; East +ve) : 175 10 55.8
Latitude (DD MM SS ; South -ve) : -38 15 43.4
Height above Sealevel (metres) : 40
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): crescent moon, light fog
Time Source (e.g. WWVH, GPS) : wwvh
Recording method (e.g. tape) : tape
Could you see the Asteroid? : no
Approx. Limiting Magnitude : 12.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 07 45
Disappearance At : 07h 50m 0.6s 0.5s
Reappearance At : 07h 50m 6.7s 0.3s
Stopped Observing : 07h 53m
Duration : 6.1 sec
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : yes
If YES, state value : as above
ADDITIONAL COMMENTS: Star very easy despite some light fog.
Observer's Name : Gary Beal
Aperture (cm) : 25
Focal length (cm) : 125
Type (e.g. SCT; Newtonian) : Newt
Magnification : 80x initially then 130x
Observing site name : Home
Longitude (DD MM SS ; East +ve) : 175 21 35 E
Latitude (DD MM SS ; South -ve) : 37 51 13 S
Height above Sealevel (metres) : 60
Geodetic Datum (e.g.WGS84,NZ1949): No Idea
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): Clearish until about 0748 then intermittant
cloud with a patch of complete cover at 0758
Time Source (e.g. WWVH, GPS) :
Recording method (e.g. tape) :
Could you see the Asteroid? : I thought I could very slightly to the NE???
Approx. Limiting Magnitude :
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Observing : 0728
Stopped Observing : 0800
ADDITIONAL COMMENTS:
The forecast wasn't too flash, and it did clag in at the end as expected.
Set up and located the star in plenty of time. I was sure I could detect a
fainter object just NE (roughly) of the target. Seeing deteriorated as the
time progressed, from about 0738 onwards, and the dimmer object was lost to
view, even with more magnification.
I did not see any dimming, or flashing, other than what I took to be as a
result of cloud. At no stage did the target star disappear completely,
except for a few short time at about 0753 when heavy cloud intervened.
Good practice, but hard on the neck!!!
Observer's Name : John Drummond
Aperture (cm) : 20cm f4
Focal length (cm) : 80
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : 50 x's
Observing site name : 1 km up the Waihau Beach (Loisels) Road, near Gisborne
Longitude (DD MM SS ; East +ve) : 178* 16'14" E
Latitude (DD MM SS ; South -ve) : 38* 28' 27" S
Height above Sealevel (metres) : 120
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Fair
Time Source (e.g. WWVH, GPS) : watch (set to phone clock pips a few hours earlier)
Recording method (e.g. tape) : tape
Could you see the Asteroid? : no
Approx. Limiting Magnitude : 13
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 07 48 00
Stopped Observing : 07 55 00
ADDITIONAL COMMENTS: A miss!!! I was certain it would be a hit...
Could clearly see the star - quite bright.
Occultation of TYC 6816-00240-1 by (184) Dejopeja - 2004 Jun 16:
A definite occultation was observed by Peter Anderson in Brisbane, indicating the path moved at least one track width north from the predicted path shown here.
Peter's duration was 6.2 secs whereas the predicted duration for a central occultation by the anticipated 66 km diameter asteroid was only 5.4 seconds. This suggests that at least one axis of the asteroid is longer than 66km. Given that predicted diameter values are based on IRAS data which only indicates an expected average diameter for the asteroid, it is perhaps reasonable to assume, based on prior experience, that the minor axis of Dejopeja may be somewhat smaller than the IRAS value. John Broughton at Reedy Creek, to the south of Brisbane, observed a miss. (A circle of diameter 66 km is plotted in the diagram below).
Dejopeja has not previously been observed at occultation.
Observers: 1 P. Anderson, Brisbane, Australia 2(M) J. Broughton, Reedy Creek, Australia M = Miss
Observational Data:
Observer's Name : Peter Anderson
Aperture (cm) : 41
Focal length (cm) : 245
Type (e.g. SCT; Newtonian) : Newt.
Magnification : X 198
Observing site name : Taylor Range Observatory
Longitude (East +ve) : 152deg 55' 54.04"
Latitude (South -ve) : -27deg 27' 47.96"
Height above Sealevel (metres) : 176.3 (Positions AGD 1966)
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Other Conditions:
(Wind, Clouds, Lights, etc.): Southerly Breeze
Time Source (e.g. WWV, VNG) : WWVH
Recording method (e.g. tape) : Tape and preset stopwatches
Could you see the Asteroid? : Yes
Approx. Limiting Magnitude : 15.0
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Monitoring : 16 56 30
Star and Object Merged : Shortly after first located at 16hrs 45min
Disappearance At : 17 01 11.0 +/- 0.2sec
Quick fade of 0.2sec but stopwatch not triggered. Comment made on tape instead.
0.7sec reaction time allowed from end of fade.
Reappearance At : 17 01 17.2sec ± 0.15sec.
0.38sec reaction time allowed.(stopwatch) Again 0.2 sec for return to full Brightness.
Time quoted is beginning of return to full brightness.
Stopped Monitoring : 17 07 00
ADDITIONAL COMMENTS:
WOW! Finally another positive one! This one was definite. There was no doubt. No other
flickerings or fadings were recorded during the 10.5 minutes of monitoring.
Observer's Name : John Broughton
Aperture (cm) : 50.1
Focal length (cm) : 185
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : CCD drift-scan, 5 pixels per second
Observing site name : Reedy Creek, Gold Coast
Longitude (East +ve) : +153 23' 49"
Latitude (South -ve) : -28 06' 36"
Height above Sealevel (metres) : 66
Geodetic Datum (e.g.WDD84,NZ1949): AGD66
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair
Time Source (e.g. WWV, VNG) : WWVH.
Recording method (e.g. tape) : Tape.
Could you see the Asteroid? : Only the combined light was monitored.
Approx. Limiting Magnitude : 14.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Observing : 17:00:10.0 0 0.2
Stopped Observing : 17:02:01.0 0 0.2
Occultation of TYC 7380-00754-1 by (772) Tanete - 2004 May 20:
This event crossed the central North Island of New Zealand before moving on to NSW. An 8.0 second occultation was observed on video by Dave Gault in NSW while a miss was recorded by Diana Watson in Whakatane, NZ and Noel Munford in Palmerston North, NZ. The fact that only one chord was obtained yields limited physical information about the asteroid (although it does provide a well-determined position for the asteroid at the time of occultation). The plot below shows a circle of Tanete's 117 km estimated diameter fitted between the two video points, with Diana's and Noel's miss events also plotted.
Observers: 1 D.Gault, Robertson, NSW, Australia 2(M) D.Watson, Whakatane, NZ 3(M) N.Munford, Palmerston North, NZ
Observational Data:
Observer's Name : Dave Gault
Aperture (cm) : 25
Focal length (cm) : 122
Type (e.g. SCT; Newtonian) : EQ Newtonian
Magnificatio : About 80x (PC164C at Newtonian focus)
Observing site name : Gwaihir Stud - Robertson
Longitude (East +ve) : 150 35 32.7
Latitude (South -ve) : -34 34 02.8
Height above Sealevel (metres) : 747.5
Datum : WGS84 and MSL
Sky Transparency : Good,
Star Image Stability : Poor (terrible) see notes
Other Conditions: : Strong wind gusts
Time Source (e.g. WWV, VNG) : GPS and KIWI
Recording method (e.g. tape) : KIWI audio pips on VIDEO
Could you see the Asteroid? : Yes at times during disappearance of star
Approx. Limiting Magnitude : 12.3 (12.6 momentary for the asteroid)
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing 09:50
Disappearance At 09:59:26.5 | N/A | 0.25 | see notes
Reappearance At 09:59:34.5 | N/A | 0.25 | see notes
Stopped Observing 10:12
COMMENTS:
I set up in strong winds at an exposed site. The wind buffeted the scope continuously
and made finding the star difficult and in the end was only achieved by sighting the L
shaped asterism consisting of TYC 7380-1099, 390, 896 and the target star TYC 7380-754.
Direct visual observations of the star would have been impossible due to the buffeting
and I decided to set up and try the video camera within the last 15 minutes. I was
surprised at the image quality achieved with the camera. I put this down to the inability
of the eye to follow the fast jiggling image and the ability of the camera to record images
at 30 frames per second. The stars in the asterism were now separated and they were easy
to watch despite their jumping all over the screen due to the wind. The recording was
trouble free but I expected the wind to blow the scope off target any second and in the end
I was amazed the scope tracked so well.
The times shown above were estimated by ear and eye by replaying the video time and time
again. I asked my wife Karen to check my timings and did not show her my estimates. She
confirmed my times within the stated accuracy and we both agree on the duration of 8 seconds.
The asteroid could be seen on occasional frames during occultation however this lasted for
only 3 or 4 frames at a time.
To confirm duration I decided to step through the sequence frame by frame and to note the
frame number the target star looses and resumes full luminance. The time is simply the read
out on the counter and is not linked to KIWI pips in any way.
Disappearance - 1m17s on frame 29
Reappearance - 1m26s on frame 14
This gives a duration of 8 1/2 seconds.
I must emphasize the usefulness of Video for Occultation Timing. Without it, this observation,
in the conditions encountered would have been impossible.
ADDITIONAL NOTES: 23/5/04
As stated in my report I timed the event by reviewing the video by ear and eye time and again.
I got my wife to check and she confirmed my results.... 8 seconds duration....
We were a little concerned about the end of the occultation as there seemed to be a flash just
before the star resumed normal brightness. It was very difficult as the stars were jumping
about a lot. I then stepped through the video frame by frame and came up with 8 1/2 seconds
duration. I examined the video for hours and in the end I convinced myself that it was nothing
and I was seeing things due to the windy conditions.
Last night Ted installed a new video player which can expand the video to cover the whole screen
and now I'm sure there is something odd with the reappearance.
Tanete can be seen on occasional frames between disappearance and reappearance but only for 1 or
2 frames at a time however at the end of the event it can be seen for 8 consecutive frames then
nothing for 5 before the image brightens to normal intensity. When played at normal speed the
occasional 1 or 2 frames give the illusion that the asteroid is very faint and the long duration
at the end gives the illusion that there is a flash.
The effect has me worried and I'm at a loss to explain, except to stress the windy conditions
present at the time.
Occultation of TYC 0837-00172-1 by (366) Vincentina - 2004 May 18:
Please refer to the separate Vincentina results page.
Occultation of TYC 5783-01228-1 by (16) Psyche - 2004 May 16:
Please refer to the separate Psyche results page.
Occultation of 2UCAC12032701 by (911) Agamemnon - 2004 May 6:
Please refer to the separate Agamemnon results page.
Occultation of TYC 6348-01230-1 by (142) Polana - 2004 April 25:
A 2.29 second occultation was observed by John Broughton from Reedy Creek, Qld, using the highly accurate CCD drift-scan method.
Observational Data:
Observer's Name : John Broughton
Aperture (cm) : 50.1
Focal length (cm) : 185
Type (e.g. SCT; Newtonian) : Newtonian
Magnification : CCD drift-scan, 5.4 pixels per second
Observing site name : Reedy Creek, Gold Coast
Longitude (East +ve) : +153.397
Latitude (South -ve) : -28.110
Height above Sealevel (metres) : 66
Sky Transparency (Delete two) : Poor
Star Image Stability (Delete two): Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): Thin Cirrus
Time Source (e.g. WWV, VNG) : WWVH.
Recording method (e.g. tape) : Tape.
Could you see the Asteroid? : Only the combined light was monitored.
Approx. Limiting Magnitude : 13.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Observing : 18:15:20.82 0.0 0.01
Disappearance At : 18:15:53.92 0.0 0.07
Reappearance At : 18:15:56.21 0.0 0.07
Stopped Observing : 18:16:41.56 0.0 0.01
ADDITIONAL COMMENTS: My 6th positive event in 10 months!
Occuring only 5s earlier than prediction, a 2.29 second occultation was
measured from a CCD image obtained using a recently completed 20" newtonian.
The poor sky transparency was offset by the gain in aperture over a 10" SCT
used on previous occasions. This is the first event that timing accuracy
is also measured rather than estimated.
Occultation of TYC 5736-00333-1 by (2060) Chiron - 2004 April 22:
An occultation of approximately 5 seconds duration was observed by Kevin Davey from Glenelg North, South Australia.
Observational Data:
Observer's Name : Kevin Davey
Aperture (cm) : 25.4
Focal length (cm) : 250
Type (e.g. SCT; Newtonian) : SCT
Magnification : 96
Observing site name : (back garden)
Longitude (DD MM SS ; East +ve) : 138 31 07
Latitude (DD MM SS ; South -ve) : -34 58 03
Height above Sealevel (metres) : 10
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) :
Sky Transparency (Delete two) : Fair
Star Image Stability (Delete two): Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): Gusting wind to ~15 km/h, naked eye limiting mag ~4.5.
Time Source (e.g. WWVH, GPS) : none (WWVH not heard on any frequency)
Recording method (e.g. tape) : voice tape
Could you see the Asteroid? : no
Approx. Limiting Magnitude : ~12.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 19:12
Disappearance At : ~19:17
Reappearance At : ~19:17:05
Stopped Observing : ~19:23
List all Interruptions to Observing:
FROM TO REASON
Break 1: ~19:17:15 ~19:17:25 Read time from analogue clock
Break 2:
ADDITIONAL COMMENTS: Timing procedures poor - inability to tune to WWVH on any of 5 SW frequencies
a major limitation.
Occultation of TYC 0439-00295-1 by (667) Denise - 2004 April 18:
A possible occultation was observed by Graham Blow from Wellington. If the event was a true occultation (see notes below) , this would suggest the path shifted eastwards by between two and three track widths.
Observational Data:
Observer's Name : Graham Blow
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtonian) : SCT
Magnification : ?
Observing site name : Khandallah
Longitude (DD MM SS ; East +ve) : +174 48 11.4
Latitude (DD MM SS ; South -ve) : -41 14 51.1
Height above Sealevel (metres) : 120
Geodetic Datum (e.g.WGS84,NZ1949): NZ1949
Height Datum (if known) : -
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Time Source (e.g. WWVH, GPS) : WWVH
Recording method (e.g. tape) : Tape
Could you see the Asteroid? : No
Approx. Limiting Magnitude : 11
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 14:35:07
Disappearance At : 14:36:10.2 > 1 sec - see below
Reappearance At : 14:36:11.0 ?0.5 sec - see below
Stopped Observing : 14:39:00
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : No
ADDITIONAL COMMENTS:
I was late setting up for this event and only started observing about a minute before the
predicted time. (I was not even sure I had the correct star until after the event). I did not
have the drive operating and was moving the telescope manually.
At a point close to the predicted time I moved my head slightly and found that I could no longer
see the relatively bright target star in the field of view, yet I felt that I could still see
fainter surrounding stars. I took a moment to assimilate this and as I slightly moved my
head again, I found I could again see the target star.
I am not certain that I saw a real occultation, but feel the chances that I did so are greater
than if I did not - I would suggest about 70% certainty. However I feel that any event "seen"
could also be due to my head moving in such a way that part of the field was momentarily blocked
by the edge of the eyepiece (notwithstanding the fact that I also felt that I could continue to
see some fainter stars). However, if the event was real (and allowing for my extremely slow
reaction time on the D) any occultation duration must have been of order 2 seconds.
Occultation of 2UCAC21564388 by (441) Bathilde - 2004 April 01:
A 16.3 second occultation was observed by Brian Loader from Darfield. The path shifted northwards by about 2-sigma compared to the expected path with a time shift of about -15 seconds. See the notes below for further details.
Observational Data:
Observer's Name : Brian Loader
Aperture (cm) : 25.4
Focal length (cm) : 250
Type (e.g. SCT; Newtonian) : SCT
Magnification : 180x
Observing site name : Darfield
Longitude (DD MM SS ; East +ve) : +172° 06' 24.4" E
Latitude (DD MM SS ; South -ve) : -43° 28' 52.9" S
Height above Sealevel (metres) : 210
Geodetic Datum (e.g.WGS84,NZ1949): WGS84
Height Datum (if known) : MSL
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair, occasionally Poor
Time Source (e.g. WWVH, GPS) : GPS
Recording method (e.g. tape) : KIWI
Could you see the Asteroid? : Just during the occultation
Approx. Limiting Magnitude : 13.5
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _________________)
Started Observing : 15:57:00
Disappearance At : 16:03:22.3 1.0 +/- 0.5 sec. Fade?
Reappearance At : 16:03:38.6 0.6 +/- 0.3 sec. Gradual
Stopped Observing : 16:10:00
Duration : 16.3 seconds
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : Yes
If YES, state value : as listed
List all Interruptions to Observing: Nil
ADDITIONAL COMMENTS:
An unexpected event, Darfield was nearly 2-sigma north of the northern edge of the predicted
path. This is equivalent to 1 path width. The expected maximum duration was 23.5 second, the
16.3 seconds suggests I was near the edge of the path.
I tried to image the star, Mv = 11.2, using video but the image was only just discernable on
the monitor, not sufficient, I felt, to be sure of any event. So I monitored the event visually.
The GSC catalogue gives the magitude as 12.1 presumably photographic magnitude. Visually, the
11.2 Mv looked reasonable for the star. I suspect less than ideal seeing was slightly limiting
the magnitude the video would pick up.
There is a 9.3 star nearby, 1.5' distant which gave a good reference point, and did not disappear
during the occulation. As usual, I was caught by surprise when the star disappeared, so my
1 second PE estimate could be an underestimate. I strongly suspect there was a noticable fade
as the star was occulted. I feel certain the reappearance was gradual, perhaps spread over as
much as half a second. The asteroid was faintly visible throughout the ocultation, shimmering on
the verge of visibility. It was not visible with the star in the field, but Bathilde was only
moving at about 3" per hour, so would have been too close 30 minutes either side of the event.
Summary: Duration of occultation about 16.3 seconds, maximum predicted 23.5 seconds. If a
spherical body, this would suggest I was about 2/3 of a radius out from mid path
The mid time of event being about 15 seconds later than predicted. Shift of path about 1.2
widths to north compared to predicted, or about 2-sigma, assuming I was north of the centre.
Occultation of TYC 4915-00664-1 by (392) Wilhelmina - 2004 March 30:
A 4.9 second occultation was observed by Ross Dickie from Gore. Maximum expected duration for the event was 5.1 seconds so Ross cannot have been far from the centre line, indicating a northward shift in the path.
Observational Data:
Observer's Name : Ross A. Dickie
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtownian) : SCT
Magnification : 93x
Observing site name : Gore.
Longitude (East +ve) : 168° 55' 20.7" E
Latitude (South -ve) : -46° 06' 22.4" S
Height above Sealevel (metres) : 81 metres.
Geodetic Datum (e.g.WGS84,NZ1949): NZ1949.
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Good
Time Source (e.g. WWV, VNG) : WWVH 10MHz
Recording method (e.g. tape) : Memorised stopwatch timed to WWVH 10MHz.
Could you see the Asteroid? : NO.
Approx. Limiting Magnitude : 13.7
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ ______________________
Started Observing : 14:09:21
Disappearance At : 14:23:30.7 (0.7 sec P.E. already subtracted)
Reappearance At : 14:23:35.6 (0.4 sec P.E. already subtracted)
Stopped Observing : 14:31:24
Duration : 4.9 sec
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : YES.
If YES, state value : As stated above.
ADDITIONAL COMMENTS:
A longer occultation during than I expected, considering that West Gore is 4.5km inside the
predicted northern limit of Wilhelmina's occultation path as predicted by Steve Preston.
The central time of my 4.9 seconds' duration is nine seconds later than that predicted by
Steve Preston for Gore.
Occultation of TYC 7850-01300-1 by (247) Eukrate - 2004 March 23:
A 7.3 second occultation was observed by Ross Dickie from Gore. Maximum expected duration for the event was 10.3 seconds so it is likely that the path shifted eastwards by about 0.75 path widths. Although the occultation shadow would have also covered Invercargill, and possibly Dunedin, no reports have been received from there. Intending observers in Christchurch and Darfield were clouded out.
Observational Data:
Observer's Name : Ross A. Dickie
Aperture (cm) : 20
Focal length (cm) : 200
Type (e.g. SCT; Newtownian) : SCT
Magnification : 133x
Observing site name : Gore.
Longitude (East +ve) : 168° 55' 20.7" E
Latitude (South -ve) : -46° 06' 22.4" S
Height above Sealevel (metres) : 81 metres.
Geodetic Datum (e.g.WGS84,NZ1949): NZ1949.
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair
Other Conditions:
(Wind, Clouds, Lights, etc.): Monitored event in between passing clouds, with some wind
from the west. Some wind shakes at beginning of my
monitoring.
Time Source (e.g. WWV, VNG) : WWVH 15MHz
Recording method (e.g. tape) : Memorised stopwatch timed to WWVH 15MHz.
Could you see the Asteroid? : At magnitude 13.8, I might have seen Eukrate during its
occultation.
Approx. Limiting Magnitude : 13.9
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
COLUMN FORMAT TO USE---> __:__:__._ _._ _______________________
Started Observing : 12:51:55
Disappearance At : 12:58:51.0 0.7 sec P.E. (already subtracted)
Reappearance At : 12:58:58.3 0.5 sec P.E. (already subtracted)
Stopped Observing : 13:01:58 Clouded out.
Duration : 7.3 sec
Was your reaction time (also known as Personal Equation) subtracted from
any of the above timings? : YES, to the D and R.
If YES, state value : As mentioned above.
ADDITIONAL COMMENTS:
No doubts an occultation by Eukrate, which is just 6½ seconds later than Steve Preston's
predicted time for Gore.
Occultation of TYC 4909-00926-1 by (509) Iolanda - 2004 March 20:
Please refer to the separate Iolanda results page.
Occultation of 2UCAC14265154 by (426) Hippo - 2004 March 1:
Please refer to the separate Hippo results page.
Occultation of HIP 50081 by (799) Gudula - 2004 February 25:
Please refer to the separate Gudula results page.
Occultation of TYC 6272-00570-1 by (100) Hekate - 2004 February 12:
A 2.0 second occultation was observed from Girrawheen, Western Australia. The observation confirms that the updated track for this event was spot on and passed directly across Perth. No other observations from the Perth region have been reported.
Observational Data:
Observer's Name : Ian Bacon
Aperture (cm) : 25
Focal length (cm) : 250
Type (e.g. SCT; Newtonian) : SCT
Magnification : 100x
Observing site name : Perth, WA
Longitude (East +ve) : 115 degrees 49 minutes 57.7 seconds east
Latitude (South -ve) : 31 degrees 50 minutes 21.9 seconds east
Height above Sealevel (metres) : 40
Sky Transparency (Delete two) : Good
Star Image Stability (Delete two): Fair
Time Source (e.g. WWV, VNG) : Telstra
Recording method (e.g. tape) : computer
Could you see the Asteroid? : no
Approx. Limiting Magnitude : 12.5+
| Estimated |
Universal Time | Reaction | Accuracy, Remarks
h m s | Time (sec) |
Started Observing : 04 33
Disappearance At : 04 36 21.0
Reappearance At : 04 36 23.0
Stopped Observing : 04 38
Duration : 2.0 sec
Reaction time subtracted : 0.5 sec
ADDITIONAL COMMENTS: The sky was bright due to the nearby Moon, however, the light drop was
clearly seen. As the star was bright the drop was dramatic. I allowed 0.5 sec rather than
0.3 sec for my reaction time because of the late hour. The duration though was definitely 2 seconds.
(A 4 second occultation by Hekate was previously observed on 14 July 2003 by Michael Mattiazzo in South Australia.)
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