Occultation event with (31342) 98MU31, event index number 4030
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/08/17 06:21:01 UTC
J2000 position of star is 05:21:25.1 +10:15:53
Equinox of date position of star is 05:22:53.3 +10:17:21
Star is 120 degrees from the moon. Moon is 23% illuminated.
Stellar brightness G=15.7, apparent brightess of occulting body is G=16.4
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 3.5 per integration for unocculted signal
Expected flux drop is 66% with SNR of 2.3 for the occulted depth (per occulted point)
Apparent velocity is 23.9 km/sec on the sky relative to the star, or, 20.3 arcsec/hr.
Position angle of asteroid motion is 88.9 degrees
The recommended exposure time corresponds to 10.8 km per image.
The 1-sigma error in the time of the event is 0.7 seconds.
The 1-sigma cross-track error in the shadow position is 31.2 km.
The sky-plane scale is 4232.8 km/arcsec.
Diameter estimates:
49.0 km assuming a 5% albedo, maximum of 2.0 sec for a central chord
20.0 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 47.4 km used for deployment plan.
Star training set for 31342_98MU31, (2026/08/17 06:21UT) Object RA Dec mag sep mel Betelgeuse 05:56:36.8 +07:24:35 0.4 8.81 111 Bellatrix 05:26:33.6 +06:22:18 1.6 4.02 118 18 Ori 05:17:33.0 +11:22:09 5.6 1.70 121 PPM 148802 05:22:21.1 +09:44:59 6.8 0.56 120 PPM 120876 05:23:31.3 +10:05:13 8.7 0.26 119 31342_98MU31 05:22:53.3 +10:17:21 16.4 119 Positions are for equinox of date
Star training set for 31342_98MU31, (2026/08/17 06:21UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 8.81 111 Bellatrix 05:25:07.8 +06:20:58 1.6 4.02 118 18 Ori 05:16:04.1 +11:20:29 5.6 1.70 121 PPM 148802 05:20:53.2 +09:43:30 6.8 0.56 120 PPM 120876 05:22:03.2 +10:03:47 8.7 0.26 119 31342_98MU31 05:21:25.1 +10:15:53 16.4 120 Positions are for J2000