This prediction update has been computed by Graham Blow based on astrometry from USNO/Flagstaff, Alex Liu in Western Australia, and Ian Griffin at Auckland Observatory. The Hipparcos position of the star has been used.

Summary:

The updated track passes just south of New Zealand; Invercargill lies less than one track width to the north.

The event time is about 90 seconds later than the Goffin prediction and about 60 seconds later than the OCCULT prediction. Updated time is about 10h 04.5m for Invercargill.

THE EVENT AT ONE GLIMPSE:

• Date and approx. UT time of event: August 10, 1999 @ 10:04.5 UT (Invercargill)
• Magnitude of target star: 9.75
• Magnitude drop [mag]: 3.8
• Estimated maximum duration [s]: 5.7
• Path description: Marginally south of New Zealand.

• Name: HIP 107661
• J2000 position [h,m,s; o,',"]: 21h 48m 27.398s; -21^o 40' 09.17"
• Position source: Hipparcos
• V mag [mag]: 9.75

• Number, name: (752) Sulamitis
• Approx. diameter [km]: 66
• Source of used astrometry: USN0/Flagstaff (Ron Stone), Exmouth (Alex Liu), Auckland (Ian Griffin)
• Number of used observations: 5 USNO + 12 Exmouth + 6 Auckland
• Number of rejected observations: 0
• Time covered by the observations: 1999 07 17 - 1999 08 08

• UT date and time of least geocentric approach: 09:57 UT
• Approx. V mag of minor planet at event [mag]: 13.56
• Geocentric parallax of minor planet ["]: 5.459
• Magnitude drop [mag]: 3.8
• Estimated maximum duration [s]: 5.7
• Apparent motion of minor planet ["/h]: 35.73
• Angular distance to moon, phase of moon [deg,%]: 160, 1%

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.