This prediction update has been computed by Stephen Kerr based on astrometry from Ron Stone of the US Navel Observatory - Flagstaff Station. The TYC-1 position of the target star has been used.

Summary:

The update path lies around 0.75 of a path width to the south and 10 seconds earlier than that given by Goffin. The path crosses the North Island of New Zealand at 14:29 UT with Auckland just on the north edge of the path. The path then crosses the southern tips of Victoria with Melbourne just on the northern edge at 14:32 UT. Wilson's Promontory and the Cape Otway districts lie near the centre of the path. The path leaves the coastline near the Vic/SA border (14:32:25 UT) before running across the Great Australian Bight. The path runs very close to the Western Australian coastline at and to the west of Albany at 14:35 UT.

Auckland and Melbourne observers are urged to monitor from sites at and to the south of their respective cities to improve the likelihood of detecting a positive event and the possibility of providing multiple chords to allow an accurate diameter/profile to be determined for 349 Debowska !!

Note that with an expected magnitude of 10.2, observers can expect to be able to see the asteroid. In this case, an occultation will appear as a dimming rather than a disapperence of the star. Careful attention is therefore required to monitor this event.

The proximity of the full moon (only 9 degrees away) will also complicate the observation and may make the field identification difficult.

THE EVENT AT ONE GLIMPSE:

• Date and approx. UT time of event: May 17, 2000 @ 14:33 UT
• Magnitude of target star: 9.42
• Magnitude drop [mag]: 1.2
• Estimated maximum duration [s]: 10.7
• Path description: See above.

• Approximate width [km]: 150

• Name: TYC 6182 371 = PPM 263933 = SAO 183258
• Constellation: Libra
• J2000 position [h,m,s; ^o,',"]: 15h 12m 06.007s; -22^o 21' 51.13"
• Position source: TYC
• V mag [mag]: 9.42
• Remarks:
• The target star is 3.5 degrees north-east of sigma Librae (mag = 3.3). The mag 5.5 star SAO 183328 lies 1 degree to the east of the target star.

• Number, name: (349) Dembowska
• Approx. diameter [km]: 143
• Source of used astrometry: US Navel Observatory - Flagstaff Station (Ron Stone)
• Number of used observations: 9
• Number of rejected observations: 0
• Time covered by the observations: 2000 04 19 - 2000 05 08

• UT date and time of least geocentric approach: 2000 May 17 14:33.626 UTC
• Approx. V mag of minor planet at event [mag]: 10.22
• Geocentric parallax of minor planet ["]: 4.16
• Magnitude drop [mag]: 1.2
• Estimated maximum duration [s]: 10.7
• Apparent motion of minor planet ["/h]: 31.49
• Angular distance to moon, phase of moon [deg,%]: 9, 99%
• Update computed by: Kerr (OCCULT 4.2)

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.