This prediction update has been computed by Steve Kerr of Rockhampton, Queensland, Australia based on astrometry from Ron Stone of the US Naval Observatory - Flagstaff Station. The Tycho 2 position of the target star has been used.

Summary:

This updated path lies around 1.5 path widths to the north of that given by Goffin and around 20 seconds earlier. The path crosses southern Wollongong (16:03:20 UT), Canberra and Albury before passing just to the north of Melbourne (16:04:10 UT) and through far southeastern South Australia (16:05 UT).

Observers should note that this update is based on only 4 astrometric positions for the asteroid and has a fairly large error tolerance - the dotted circle in the lower left corner of the graphic represents the 95% confidence limit based on the asteroid position ONLY (ie. assumes NO error in star position). As such, an occultation is quite possible in Sydney, Melbourne and Adelaide and even a remote possibility in Auckland (16:00:30 UT).

Observers should also note that the target star is faint - magnitude = 11.75. It is the fainter and western half of a close pair around 80" apart (the other star is TYC (GSC) 5234-00753-1). This star is plotted on the printed versions of Goffin's prediction and is visible within the circle to the lower left of the target star. The asteroid itself is predicted to be magnitude 12.7 at the time and any observer who can comfortably monitor the target star will probably be able to see the asteroid during any occultation.

THE EVENT AT ONE GLIMPSE:

• Date and approx. UT time of event: August 16, 2001 @ 16:03 UT
• Magnitude of target star: 11.75
• Magnitude drop [mag]: 1.3
• Estimated maximum duration [s]: 5.7
• Path description: See above.
• Goffin's original chart reference: A01_0822

• Approximate width [km]: 70
• Uncertainty [km]: 350 (95% confidence)
• Map: See below
• Circles along the path are OCCULT calculated exact centerline points !!!!

• Name: TYC 5234-00774-1
• Constellation: Aquarius
• J2000 position [h,m,s; ^o,',"]: 22h 42m 10.365s; -0^o 54' 46.23"
• Position source: TYC 2
• V mag [mag]: 11.75
• Remarks:
• The target star is in northeastern Aquarius. It lies around 1.9 degrees southeast of eta Aquarii (magnitude = 4.0). There is a brighter companion around 80" to the east of the target star as noted in the description at the top of this update.

• Number, name: (338) Budrosa
• Approx. diameter [km]: 62
• Source of used astrometry: US Naval Observatory - Flagstaff Station (Ron Stone)
• Number of used observations: 4
• Number of rejected observations: 0
• Time covered by the observations: 2001 07 16 - 2001 08 02

• UT date and time of least geocentric approach: 2001 August 16, 16:04.9 UT
• Approx. V mag of minor planet at event [mag]: 12.72
• Geocentric parallax of minor planet ["]: 4.58
• Magnitude drop [mag]: 1.3
• Estimated maximum duration [s]: 5.7
• Apparent motion of minor planet ["/h]: 28.07
• Angular distance to moon, phase of moon [deg,%]: 127, 9%
• Update computed by: Steve Kerr, Rockhampton, Queensland Australia. (Win Occult V1.4).

IMPORTANT NOTE!

Astrometric updates such as these should not be taken as definitive, but rather only as an indication of where the true track may lie relative to the original predicted track. Observers must bear in mind that later astrometry, in which the target star is measured in the same field as the asteroid, may still reveal substantial changes to the predicted track and time of the event. For this reason it is most important that observers far from the predicted track still monitor the event.