Occultation event with (9142) Rhesus, event index number 4478
Regions able to see the event: Europe
Geocentric closest approach at 2026/10/25 00:46:44 UTC
J2000 position of star is 05:21:38.1 +09:19:29
Equinox of date position of star is 05:23:06.4 +09:20:57
Star is 66 degrees from the moon. Moon is 98% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=16.1
Use an exposure time of 1.15 seconds with the standard RECON-QHY system.
SNR of 3.9 per integration for unocculted signal
Expected flux drop is 44% with SNR of 1.7 for the occulted depth (per occulted point)
Apparent velocity is 8.8 km/sec on the sky relative to the star, or, 9.3 arcsec/hr.
Position angle of asteroid motion is 60.1 degrees
The recommended exposure time corresponds to 10.1 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 21.5 km.
The sky-plane scale is 3399.5 km/arcsec.
Diameter estimates:
43.7 km assuming a 5% albedo, maximum of 4.9 sec for a central chord
17.8 km assuming a 30% albedo, maximum of 2.0 sec for a central chord
Cross-track diameter of 42.3 km used for deployment plan.
Star training set for 9142_Rhesus, (2026/10/25 00:47UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.5 +07:24:35 0.4 8.51 74 Bellatrix 05:26:34.2 +06:22:18 1.6 3.10 67 18 Ori 05:17:33.6 +11:22:09 5.6 2.44 64 PPM 148802 05:22:21.7 +09:45:00 6.8 0.44 65 PPM 148797 05:22:15.6 +09:22:09 9.2 0.21 65 9142_Rhesus 05:23:06.4 +09:20:57 16.1 66 Positions are for equinox of date
Star training set for 9142_Rhesus, (2026/10/25 00:47UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 8.51 74 Bellatrix 05:25:07.8 +06:20:58 1.6 3.10 67 18 Ori 05:16:04.1 +11:20:29 5.6 2.44 64 PPM 148802 05:20:53.2 +09:43:30 6.8 0.44 65 PPM 148797 05:20:47.3 +09:20:39 9.2 0.21 65 9142_Rhesus 05:21:38.1 +09:19:29 16.1 66 Positions are for J2000