Occultation event with (4902) Thessandrus, event index number 3243
Regions able to see the event: NZ
Geocentric closest approach at 2026/02/13 10:58:05 UTC
J2000 position of star is 11:44:36.9 +01:38:02
Equinox of date position of star is 11:45:57.3 +01:29:19
Star is 102 degrees from the moon. Moon is 16% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=14.9
Use an exposure time of 1.05 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 20% with SNR of 0.6 for the occulted depth (per occulted point)
Apparent velocity is 12.9 km/sec on the sky relative to the star, or, 14.9 arcsec/hr.
Position angle of asteroid motion is 122.6 degrees
The recommended exposure time corresponds to 13.6 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 25.8 km.
The sky-plane scale is 3126.3 km/arcsec.
Diameter estimates:
64.9 km assuming a 5% albedo, maximum of 5.0 sec for a central chord
26.5 km assuming a 30% albedo, maximum of 2.1 sec for a central chord
Cross-track diameter of 51.3 km used for deployment plan.
Star training set for 4902_Thessandrus, (2026/02/13 10:58UT) Object RA Dec mag sep mel Regulus 10:09:45.6 +11:50:19 1.3 26.00 128 Denebola 11:50:23.4 +14:25:33 2.1 12.98 107 5Bet Vir 11:52:03.3 +01:37:03 3.6 1.53 101 PPM 158179 11:47:02.3 +02:40:32 8.4 1.22 102 PPM 158166 11:46:25.9 +01:26:00 9.8 0.13 102 4902_Thessandr 11:45:57.3 +01:29:19 14.9 101 Positions are for equinox of date
Star training set for 4902_Thessandrus, (2026/02/13 10:58UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 26.00 128 Denebola 11:49:02.7 +14:34:16 2.1 12.98 107 5Bet Vir 11:50:43.0 +01:45:46 3.6 1.53 101 PPM 158179 11:45:41.9 +02:49:14 8.4 1.22 102 PPM 158166 11:45:05.5 +01:34:43 9.8 0.13 102 4902_Thessandr 11:44:36.9 +01:38:02 14.9 102 Positions are for J2000