Occultation event with (12126) 99RM11, event index number 1241
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/08/19 01:29:46 UTC
J2000 position of star is 03:22:44.8 +20:14:34
Equinox of date position of star is 03:24:13.4 +20:19:58
Star is 40 degrees from the moon. Moon is 20% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=15.8
Use an exposure time of 1.25 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 32% with SNR of 0.9 for the occulted depth (per occulted point)
Apparent velocity is 10.3 km/sec on the sky relative to the star, or, 9.9 arcsec/hr.
Position angle of asteroid motion is 69.5 degrees
The recommended exposure time corresponds to 12.8 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 22.2 km.
The sky-plane scale is 3745.8 km/arcsec.
Diameter estimates:
56.5 km assuming a 5% albedo, aximum of 5.5 sec for a central chord
23.1 km assuming a 30% albedo, maximum of 2.2 sec for a central chord
Cross-track diameter of 53.2 km used for deployment plan.
Star training set for 12126_99RM11, (2025/08/19 01:30UT) Object RA Dec mag sep mel Aldebaran 04:37:23.7 +16:33:31 0.8 17.75 26 44Zet Per 03:55:45.0 +31:57:27 2.8 13.60 31 63Tau2Ari 03:24:14.0 +20:49:55 6.2 0.50 40 PPM 119052 03:25:29.4 +19:59:47 8.2 0.45 40 PPM 092421 03:22:32.0 +20:22:54 9.6 0.40 41 PPM 092446 03:24:03.5 +20:13:44 10.4 0.11 40 12126_99RM11 03:24:13.4 +20:19:58 15.8 40 Positions are for equinox of date
Star training set for 12126_99RM11, (2025/08/19 01:30UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 17.75 26 44Zet Per 03:54:07.9 +31:53:01 2.8 13.60 31 63Tau2Ari 03:22:45.1 +20:44:31 6.2 0.50 40 PPM 119052 03:24:00.9 +19:54:25 8.2 0.45 40 PPM 092421 03:21:03.4 +20:17:27 9.6 0.40 41 PPM 092446 03:22:35.0 +20:08:20 10.4 0.11 40 12126_99RM11 03:22:44.8 +20:14:34 15.8 40 Positions are for J2000