This prediction update has been computed by Stephen Kerr 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 to 1.5 path widths to the south of that given by Goffin and around 15 seconds later. This new path crosses the east coast of the North Island just to the south of Gisborne (12:44:30 UT). Running westward, the path includes Taupo and Te Kuiti leaving the west coast at 12:45:30 UT. Rotorua lies VERY close to the north edge at 12:45:00 and the closest approach to Hamilton and Auckland will occur 15 seconds either side of 12:45:30 UT. Observers should note that on the diagram below, the centre line of the path is indicated by the line of circles rather than the time graduated lines.

In Australia, the path crosses the coast in the Wollongong/Campbelltown area (12:50:30 UT) before running west. It passes just to the south of Bathurst and Orange (12:51 UT) before running on to Forbes and to the south of Broken Hill. In South Australia, the path runs very close to Woomera (12:53 UT). At VERY low altitude (5°), the path includes Shark Bay in Western Australia (12:55:30 UT).

Observers should note that this update has been made using only 6 astrometric positions for the asteroid. However, given the very close agreement between Goffin's prediction, OCCULT's prediction, this update and the prediction given by Guide 7, reasonable confidence can be placed in the predicted path. (The path given by Guide 7 is geographically identical to the updated path given here but is 1 minute earlier for all locations)

THE EVENT AT ONE GLIMPSE:

• Date and approx. UT time of event: February 15, 2001 @ 12:45 UT
• Magnitude of target star: 10.64
• Magnitude drop [mag]: 3.5
• Estimated maximum duration [s]: 10.2
• Path description: See above.
• Goffin's original chart reference: A01_0230

• Approximate width [km]: 65
• Map: See below
• Circles along the path are OCCULT calculated exact centerline points !!!!

• Name: TYC 5522-00990-1 = PPM 225355
• Constellation: Corvus
• J2000 position [h,m,s; ^o,',"]: 12h 06m 03.587s; -12^o 20' 01.14"
• Position source: Tycho 2
• V mag [mag]: 10.64
• Remarks:
• The target star is in far north-western Corvus. It is 5.7 degrees north-west of gamma Corvi (magnitude = 2.6). The magnitude 6.8 star SAO 157 086 = PPM 225366 lies only 10' to the north-east of the target star.

• Number, name: (284) Amalia
• Approx. diameter [km]: 55
• Source of used astrometry: US Naval Observatory - Flagstaff Station (Ron Stone)
• Number of used observations: 6
• Number of rejected observations: 0
• Time covered by the observations: 2000 12 16 - 2001 02 02

• UT date and time of least geocentric approach: 2001 February 15, 12:37.7 UT
• Approx. V mag of minor planet at event [mag]: 14.07
• Geocentric parallax of minor planet ["]: 5.21
• Magnitude drop [mag]: 3.5
• Estimated maximum duration [s]: 10.2
• Apparent motion of minor planet ["/h]: 15.81
• Angular distance to moon, phase of moon [deg,%]: 57, 46%
• Update computed by: Stephen Kerr (Win OCCULT 1.4).

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.