This prediction update has been computed by Steve Preston of the Medina, Washington (state) in the United States based on astrometry from Ron Stone of the US Naval Observatory - Flagstaff Station supplemented with data from the AstDys database. The UCAC position of the target star has been used.

Summary:

This updated path lies around 0.4" to the south of that given by Goffin and around 1 minute later. The path now passes to the north of the North Island of New Zealand around 15:40 UT before running across the Tasman Sea and through Bass Strait (15:44 UT).

The error tolerances on this calculation are quite large and the major centres of Melbourne and Hobart (15:44 UT), and Canberra and Sydney (15:43) all lie within the range of a possible occultation.

Observers are warned that the target star is quite faint (magnitude = 11.7) and users of small telescopes may have difficulty locating the field in the bright moon conditions.

THE EVENT AT ONE GLIMPSE:

• Date and approx. UT time of event: August 2, 2001 @ 15:43 UT
• Magnitude of target star: 11.71
• Magnitude drop [mag]: 2.5
• Estimated maximum duration [s]: 5.5
• Path description: See above.
• Goffin's original chart reference: A01_0839

• Approximate width [km]: 48
• Uncertainty [path widths]: 3.1 (one sigma)
• Map: See below
• Circles along the path are OCCULT calculated exact centerline points !!!!

• Name: TYC 5808-01623-1
• Constellation: Aquarius
• J2000 position [h,m,s; ^o,',"]: 22h 07m 33.6375s; -14^o 46' 39.500"
• Position source: UCAC
• Estimated accuracy ["]: 0.040" (0.031", 0.030")
• V mag [mag]: 11.7
• Remarks:
• The target star is in eastern Aquarius near the Capricornus border. It lies just under a degree south of iota Aquarii (magnitude = 4.3).

• Number, name: (1332) Marconia
• Approx. diameter [km]: 49.5
• Source of used astrometry: US Naval Observatory - Flagstaff Station (Ron Stone), AstDys
• Number of used observations: 284
• Number of rejected observations: 25
• Time covered by the observations: 1905 10 25 - 2001 07 20
• Residuals ["] (RA,DE): 0.100", 0.078" (1 sigma)

• UT date and time of least geocentric approach: 2001 August 2, 15:42.6 UT
• Approx. V mag of minor planet at event [mag]: 14.13
• Geocentric parallax of minor planet ["]: 4.99
• Magnitude drop [mag]: 2.5
• Estimated maximum duration [s]: 5.5
• Apparent motion of minor planet ["/h]: 25.51
• Angular distance to moon, phase of moon [deg,%]: 36, 98%
• Update computed by: Steve Preston, Medina, Washington, USA. (OrbFit).

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.