Occultation event with (31342) 98MU31, event index number 1732
Regions able to see the event: Australia
Geocentric closest approach at 2025/12/28 14:22:04 UTC
J2000 position of star is 03:11:37.3 -04:49:08
Equinox of date position of star is 03:12:55.1 -04:43:19
Star is 36 degrees from the moon. Moon is 59% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 6.3 per integration for unocculted signal
Expected flux drop is 58% with SNR of 3.6 for the occulted depth (per occulted point)
Apparent velocity is 13.1 km/sec on the sky relative to the star, or, 13.7 arcsec/hr.
Position angle of asteroid motion is 136.3 degrees
The recommended exposure time corresponds to 11.8 km per image.
The 1-sigma error in the time of the event is 0.8 seconds.
The 1-sigma cross-track error in the shadow position is 31.6 km.
The sky-plane scale is 3446.3 km/arcsec.
Diameter estimates:
49.0 km assuming a 5% albedo, aximum of 3.7 sec for a central chord
20.0 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 47.4 km used for deployment plan.
Star training set for 31342_98MU31, (2025/12/28 14:22UT) Object RA Dec mag sep mel Aldebaran 04:37:24.9 +16:33:34 0.8 29.82 53 Menkar 03:03:38.5 +04:11:24 2.5 9.21 31 PPM 185494 03:12:37.0 -03:42:54 6.0 1.01 36 PPM 185483 03:11:56.1 -05:17:48 8.2 0.62 36 PPM 185491 03:12:25.8 -04:35:36 9.5 0.18 36 31342_98MU31 03:12:55.1 -04:43:19 15.9 36 Positions are for equinox of date
Star training set for 31342_98MU31, (2025/12/28 14:22UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 29.82 53 Menkar 03:02:16.8 +04:05:21 2.5 9.21 31 PPM 185494 03:11:18.8 -03:48:42 6.0 1.01 36 PPM 185483 03:10:38.6 -05:23:38 8.2 0.62 36 PPM 185491 03:11:08.0 -04:41:25 9.5 0.18 36 31342_98MU31 03:11:37.3 -04:49:08 15.9 36 Positions are for J2000