Occultation event with (31342) 98MU31, event index number 3891
Regions able to see the event: Australia
Geocentric closest approach at 2026/07/26 18:51:59 UTC
J2000 position of star is 05:08:00.9 +10:04:52
Equinox of date position of star is 05:09:28.8 +10:06:50
Star is 157 degrees from the moon. Moon is 93% illuminated.
Stellar brightness G=14.8, apparent brightess of occulting body is G=16.4
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 6.2 per integration for unocculted signal
Expected flux drop is 82% with SNR of 5.1 for the occulted depth (per occulted point)
Apparent velocity is 31.3 km/sec on the sky relative to the star, or, 25.5 arcsec/hr.
Position angle of asteroid motion is 85.0 degrees
The recommended exposure time corresponds to 11.0 km per image.
The 1-sigma error in the time of the event is 0.6 seconds.
The 1-sigma cross-track error in the shadow position is 29.7 km.
The sky-plane scale is 4421.3 km/arcsec.
Diameter estimates:
49.0 km assuming a 5% albedo, maximum of 1.6 sec for a central chord
20.0 km assuming a 30% albedo, maximum of 0.6 sec for a central chord
Cross-track diameter of 47.4 km used for deployment plan.
Star training set for 31342_98MU31, (2026/07/26 18:52UT) Object RA Dec mag sep mel Aldebaran 04:37:26.9 +16:33:38 0.8 10.11 155 Bellatrix 05:26:33.4 +06:22:17 1.6 5.64 156 16 Ori 05:10:47.5 +09:51:41 5.4 0.41 157 PPM 148551 05:11:35.8 +09:59:38 7.5 0.53 157 PPM 148527 05:10:58.8 +09:57:03 10.0 0.40 157 PPM 120620 05:08:55.7 +10:08:16 10.7 0.14 157 31342_98MU31 05:09:28.8 +10:06:50 16.4 157 Positions are for equinox of date
Star training set for 31342_98MU31, (2026/07/26 18:52UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 10.11 155 Bellatrix 05:25:07.8 +06:20:58 1.6 5.64 156 16 Ori 05:09:19.7 +09:49:46 5.4 0.41 157 PPM 148551 05:10:08.0 +09:57:45 7.5 0.53 157 PPM 148527 05:09:31.0 +09:55:08 10.0 0.40 157 PPM 120620 05:07:27.8 +10:06:16 10.7 0.14 157 31342_98MU31 05:08:00.9 +10:04:52 16.4 157 Positions are for J2000