Occultation event with (31342) 98MU31, event index number 4242
Regions able to see the event: SAmericaN,SAmericaS
Geocentric closest approach at 2026/09/15 07:49:19 UTC
J2000 position of star is 05:33:43.5 +10:10:11
Equinox of date position of star is 05:35:12.0 +10:11:11
Star is 136 degrees from the moon. Moon is 19% illuminated.
Stellar brightness G=13.5, apparent brightess of occulting body is G=16.3
Use an exposure time of 0.16 seconds with the standard RECON-QHY system.
SNR of 9.6 per integration for unocculted signal
Expected flux drop is 93% with SNR of 8.9 for the occulted depth (per occulted point)
Apparent velocity is 11.3 km/sec on the sky relative to the star, or, 10.4 arcsec/hr.
Position angle of asteroid motion is 96.6 degrees
The recommended exposure time corresponds to 1.8 km per image.
The 1-sigma error in the time of the event is 1.0 seconds.
The 1-sigma cross-track error in the shadow position is 33.5 km.
The sky-plane scale is 3928.4 km/arcsec.
Diameter estimates:
49.0 km assuming a 5% albedo, maximum of 4.3 sec for a central chord
20.0 km assuming a 30% albedo, maximum of 1.8 sec for a central chord
Cross-track diameter of 47.4 km used for deployment plan.
Star training set for 31342_98MU31, (2026/09/15 07:49UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.1 +07:24:35 0.4 5.98 130 Bellatrix 05:26:33.9 +06:22:18 1.6 4.37 137 PPM 121138 05:36:41.7 +10:15:20 5.7 0.37 136 PPM 121146 05:36:54.0 +10:31:59 7.9 0.54 136 PPM 121109 05:35:18.8 +10:05:20 9.9 0.10 136 31342_98MU31 05:35:12.0 +10:11:11 16.3 136 Positions are for equinox of date
Star training set for 31342_98MU31, (2026/09/15 07:49UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 5.98 130 Bellatrix 05:25:07.8 +06:20:58 1.6 4.37 137 PPM 121138 05:35:13.2 +10:14:24 5.7 0.37 136 PPM 121146 05:35:25.3 +10:31:03 7.9 0.54 136 PPM 121109 05:33:50.3 +10:04:21 9.9 0.10 136 31342_98MU31 05:33:43.5 +10:10:11 16.3 136 Positions are for J2000