Occultation event with (9142) Rhesus, event index number 1184
Regions able to see the event: Australia,NZ
Geocentric closest approach at 2025/08/03 18:15:13 UTC
J2000 position of star is 03:08:08.3 +04:48:25
Equinox of date position of star is 03:09:29.1 +04:54:14
Star is 153 degrees from the moon. Moon is 71% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=16.2
Use an exposure time of 1.20 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 39% with SNR of 1.2 for the occulted depth (per occulted point)
Apparent velocity is 16.4 km/sec on the sky relative to the star, or, 16.6 arcsec/hr.
The recommended exposure time corresponds to 19.7 km per image.
The 1-sigma error in the time of the event is 2.8 seconds.
The 1-sigma cross-track error in the shadow position is 18.0 km.
The sky-plane scale is 3569.0 km/arcsec.
Diameter estimates:
43.7 km assuming a 5% albedo, aximum of 2.7 sec for a central chord
17.8 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 43.7 km used for deployment plan.
Star training set for 9142_Rhesus, (2025/08/03 18:15UT) Object RA Dec mag sep mel Aldebaran 04:37:23.5 +16:33:31 0.8 24.50 169 Menkar 03:03:37.2 +04:11:19 2.5 1.63 152 93 Cet 03:03:43.1 +04:27:08 5.4 1.51 152 PPM 146238 03:07:43.0 +03:54:28 7.7 1.09 152 PPM 146253 03:08:35.7 +05:07:02 9.9 0.31 154 9142_Rhesus 03:09:29.1 +04:54:14 16.2 154 Positions are for equinox of date
Star training set for 9142_Rhesus, (2025/08/03 18:15UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 24.50 169 Menkar 03:02:16.8 +04:05:21 2.5 1.63 152 93 Cet 03:02:22.6 +04:21:11 5.4 1.51 152 PPM 146238 03:06:22.6 +03:48:36 7.7 1.09 152 PPM 146253 03:07:14.8 +05:01:12 9.9 0.31 154 9142_Rhesus 03:08:08.3 +04:48:25 16.2 153 Positions are for J2000