Occultation event with (1868) Thersites, event index number 3219
Regions able to see the event: SAmericaN,SAfrica
Geocentric closest approach at 2026/02/07 02:38:54 UTC
J2000 position of star is 11:03:26.6 -05:59:16
Equinox of date position of star is 11:04:45.9 -06:07:43
Star is 33 degrees from the moon. Moon is 73% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=15.0
Use an exposure time of 1.55 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 18% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 14.4 km/sec on the sky relative to the star, or, 14.4 arcsec/hr.
Position angle of asteroid motion is 113.0 degrees
The recommended exposure time corresponds to 22.3 km per image.
The 1-sigma error in the time of the event is 1.5 seconds.
The 1-sigma cross-track error in the shadow position is 34.0 km.
The sky-plane scale is 3603.2 km/arcsec.
Diameter estimates:
76.9 km assuming a 5% albedo, maximum of 5.4 sec for a central chord
31.4 km assuming a 30% albedo, maximum of 2.2 sec for a central chord
Cross-track diameter of 68.2 km used for deployment plan.
Star training set for 1868_Thersites, (2026/02/07 02:39UT) Object RA Dec mag sep mel Regulus 10:09:45.6 +11:50:19 1.3 22.58 52 4Gam Crv 12:17:09.1 -17:41:12 2.6 21.11 15 61 Leo 11:03:09.6 -02:37:33 6.1 3.53 34 PPM 194050 11:04:05.4 -06:32:05 7.7 0.44 33 PPM 194063 11:04:35.5 -06:01:38 9.8 0.11 33 1868_Thersites 11:04:45.9 -06:07:43 15.0 32 Positions are for equinox of date
Star training set for 1868_Thersites, (2026/02/07 02:39UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 22.58 52 4Gam Crv 12:15:48.1 -17:32:30 2.6 21.11 15 61 Leo 11:01:49.7 -02:29:06 6.1 3.53 34 PPM 194050 11:02:46.1 -06:23:38 7.7 0.44 33 PPM 194063 11:03:16.1 -05:53:11 9.8 0.11 33 1868_Thersites 11:03:26.6 -05:59:16 15.0 33 Positions are for J2000