Occultation event with (9142) Rhesus, event index number 4216
Regions able to see the event: NMexico
Geocentric closest approach at 2026/09/10 10:15:22 UTC
J2000 position of star is 05:18:51.8 +10:41:29
Equinox of date position of star is 05:20:20.5 +10:43:03
Star is 79 degrees from the moon. Moon is 1% illuminated.
Stellar brightness G=12.1, apparent brightess of occulting body is G=16.4
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 20.2 per integration for unocculted signal
Expected flux drop is 98% with SNR of 19.8 for the occulted depth (per occulted point)
Apparent velocity is 13.7 km/sec on the sky relative to the star, or, 12.8 arcsec/hr.
Position angle of asteroid motion is 107.3 degrees
The recommended exposure time corresponds to 1.6 km per image.
The 1-sigma error in the time of the event is 0.3 seconds.
The 1-sigma cross-track error in the shadow position is 28.1 km.
The sky-plane scale is 3828.9 km/arcsec.
Diameter estimates:
43.7 km assuming a 5% albedo, maximum of 3.2 sec for a central chord
17.8 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 42.3 km used for deployment plan.
Star training set for 9142_Rhesus, (2026/09/10 10:15UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.1 +07:24:35 0.4 9.55 70 Bellatrix 05:26:33.8 +06:22:18 1.6 4.61 78 18 Ori 05:17:33.2 +11:22:09 5.6 0.94 80 PPM 120822 05:20:34.7 +10:33:33 8.1 0.17 79 PPM 120826 05:20:48.4 +10:45:15 8.9 0.12 79 9142_Rhesus 05:20:20.5 +10:43:03 16.4 79 Positions are for equinox of date
Star training set for 9142_Rhesus, (2026/09/10 10:15UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 9.55 70 Bellatrix 05:25:07.8 +06:20:58 1.6 4.61 78 18 Ori 05:16:04.1 +11:20:29 5.6 0.94 80 PPM 120822 05:19:06.1 +10:32:00 8.1 0.17 79 PPM 120826 05:19:19.7 +10:43:42 8.9 0.12 79 9142_Rhesus 05:18:51.8 +10:41:29 16.4 79 Positions are for J2000