Occultation event with (9142) Rhesus, event index number 4380
Regions able to see the event: Europe
Geocentric closest approach at 2026/10/11 03:24:11 UTC
J2000 position of star is 05:23:28.1 +09:46:12
Equinox of date position of star is 05:24:56.6 +09:47:36
Star is 121 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=14.1, apparent brightess of occulting body is G=16.2
Use an exposure time of 0.30 seconds with the standard RECON-QHY system.
SNR of 9.5 per integration for unocculted signal
Expected flux drop is 87% with SNR of 8.3 for the occulted depth (per occulted point)
Apparent velocity is 5.0 km/sec on the sky relative to the star, or, 5.1 arcsec/hr.
Position angle of asteroid motion is 18.1 degrees
The recommended exposure time corresponds to 1.5 km per image.
The 1-sigma error in the time of the event is 5.6 seconds.
The 1-sigma cross-track error in the shadow position is 4.0 km.
The sky-plane scale is 3518.3 km/arcsec.
Diameter estimates:
43.7 km assuming a 5% albedo, maximum of 8.7 sec for a central chord
17.8 km assuming a 30% albedo, maximum of 3.6 sec for a central chord
Cross-track diameter of 42.3 km used for deployment plan.
Star training set for 9142_Rhesus, (2026/10/11 03:24UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.3 +07:24:35 0.4 8.18 112 Bellatrix 05:26:34.1 +06:22:18 1.6 3.45 120 18 Ori 05:17:33.5 +11:22:09 5.6 2.40 123 PPM 148802 05:22:21.6 +09:45:00 6.8 0.64 121 PPM 148891 05:25:50.9 +09:31:08 9.7 0.35 120 PPM 148830 05:23:34.3 +09:43:28 10.6 0.34 121 9142_Rhesus 05:24:56.6 +09:47:36 16.2 120 Positions are for equinox of date
Star training set for 9142_Rhesus, (2026/10/11 03:24UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 8.18 112 Bellatrix 05:25:07.8 +06:20:58 1.6 3.45 120 18 Ori 05:16:04.1 +11:20:29 5.6 2.40 123 PPM 148802 05:20:53.2 +09:43:30 6.8 0.64 121 PPM 148891 05:24:22.6 +09:29:46 9.7 0.35 120 PPM 148830 05:22:05.9 +09:42:01 10.6 0.34 121 9142_Rhesus 05:23:28.1 +09:46:12 16.2 121 Positions are for J2000