Occultation event with (4902) Thessandrus, event index number 3307
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/02/25 05:47:59 UTC
J2000 position of star is 11:40:07.3 +02:19:31
Equinox of date position of star is 11:41:27.8 +02:10:49
Star is 98 degrees from the moon. Moon is 58% illuminated.
Stellar brightness G=13.4, apparent brightess of occulting body is G=14.7
Use an exposure time of 0.15 seconds with the standard RECON-QHY system.
SNR of 9.6 per integration for unocculted signal
Expected flux drop is 77% with SNR of 7.4 for the occulted depth (per occulted point)
Apparent velocity is 15.7 km/sec on the sky relative to the star, or, 18.4 arcsec/hr.
Position angle of asteroid motion is 121.0 degrees
The recommended exposure time corresponds to 2.4 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 26.6 km.
The sky-plane scale is 3070.1 km/arcsec.
Diameter estimates:
64.9 km assuming a 5% albedo, maximum of 4.1 sec for a central chord
26.5 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 51.3 km used for deployment plan.
Star training set for 4902_Thessandrus, (2026/02/25 05:48UT) Object RA Dec mag sep mel Regulus 10:09:45.7 +11:50:18 1.3 24.69 74 Denebola 11:50:23.5 +14:25:33 2.1 12.44 94 89 Leo 11:35:42.3 +02:54:52 6.2 1.61 97 PPM 158073 11:40:48.6 +02:42:08 8.4 0.55 98 PPM 158056 11:39:45.8 +02:13:11 10.0 0.43 98 PPM 158081 11:41:09.1 +02:25:09 11.0 0.25 98 4902_Thessandr 11:41:27.8 +02:10:49 14.7 99 Positions are for equinox of date
Star training set for 4902_Thessandrus, (2026/02/25 05:48UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 24.69 74 Denebola 11:49:02.7 +14:34:16 2.1 12.44 94 89 Leo 11:34:21.6 +03:03:34 6.2 1.61 97 PPM 158073 11:39:28.0 +02:50:50 8.4 0.55 98 PPM 158056 11:38:25.2 +02:21:52 10.0 0.43 98 PPM 158081 11:39:48.5 +02:33:51 11.0 0.25 98 4902_Thessandr 11:40:07.3 +02:19:31 14.7 98 Positions are for J2000