Occultation event with (1868) Thersites, event index number 3489
Regions able to see the event: SAmericaS
Geocentric closest approach at 2026/03/23 05:05:34 UTC
J2000 position of star is 10:45:01.2 -03:20:36
Equinox of date position of star is 10:46:21.2 -03:28:54
Star is 107 degrees from the moon. Moon is 22% illuminated.
Stellar brightness G=13.7, apparent brightess of occulting body is G=14.9
Use an exposure time of 0.20 seconds with the standard RECON-QHY system.
SNR of 9.2 per integration for unocculted signal
Expected flux drop is 75% with SNR of 6.9 for the occulted depth (per occulted point)
Apparent velocity is 17.7 km/sec on the sky relative to the star, or, 18.0 arcsec/hr.
Position angle of asteroid motion is 126.9 degrees
The recommended exposure time corresponds to 3.5 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 27.2 km.
The sky-plane scale is 3548.2 km/arcsec.
Diameter estimates:
76.9 km assuming a 5% albedo, maximum of 4.3 sec for a central chord
31.4 km assuming a 30% albedo, maximum of 1.8 sec for a central chord
Cross-track diameter of 68.2 km used for deployment plan.
Star training set for 1868_Thersites, (2026/03/23 05:06UT) Object RA Dec mag sep mel Regulus 10:09:46.0 +11:50:17 1.3 17.82 92 PPM 193861 10:52:25.4 -03:13:56 5.8 1.54 108 PPM 193694 10:43:14.6 -04:12:44 8.5 1.07 106 PPM 193750 10:46:40.2 -03:24:56 9.1 0.10 107 1868_Thersites 10:46:21.2 -03:28:54 14.9 107 Positions are for equinox of date
Star training set for 1868_Thersites, (2026/03/23 05:06UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 17.82 92 PPM 193861 10:51:05.3 -03:05:34 5.8 1.54 108 PPM 193694 10:41:54.8 -04:04:28 8.5 1.07 106 PPM 193750 10:45:20.2 -03:16:38 9.1 0.10 107 1868_Thersites 10:45:01.2 -03:20:36 14.9 107 Positions are for J2000