Occultation event with (12126) 99RM11, event index number 1698
Regions able to see the event: Australia
Geocentric closest approach at 2025/12/19 14:20:10 UTC
J2000 position of star is 02:46:42.3 +18:15:12
Equinox of date position of star is 02:48:09.8 +18:21:39
Star is 142 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=15.3, apparent brightess of occulting body is G=15.5
Use an exposure time of 1.35 seconds with the standard RECON-QHY system.
SNR of 9.5 per integration for unocculted signal
Expected flux drop is 55% with SNR of 5.2 for the occulted depth (per occulted point)
Apparent velocity is 9.8 km/sec on the sky relative to the star, or, 10.3 arcsec/hr.
Position angle of asteroid motion is 69.8 degrees
The recommended exposure time corresponds to 13.2 km per image.
The 1-sigma error in the time of the event is 1.8 seconds.
The 1-sigma cross-track error in the shadow position is 22.2 km.
The sky-plane scale is 3427.6 km/arcsec.
Diameter estimates:
56.5 km assuming a 5% albedo, aximum of 5.8 sec for a central chord
23.1 km assuming a 30% albedo, maximum of 2.3 sec for a central chord
Cross-track diameter of 53.2 km used for deployment plan.
Star training set for 12126_99RM11, (2025/12/19 14:20UT) Object RA Dec mag sep mel Aldebaran 04:37:24.8 +16:33:34 0.8 26.09 163 Hamal 02:08:38.6 +23:35:02 2.0 10.60 135 36 Ari 02:45:46.4 +17:52:20 6.4 0.75 141 40 Ari 02:49:59.8 +18:23:25 7.3 0.44 142 PPM 118547 02:49:00.9 +18:37:04 8.8 0.33 142 12126_99RM11 02:48:09.8 +18:21:39 15.5 142 Positions are for equinox of date
Star training set for 12126_99RM11, (2025/12/19 14:20UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 26.09 163 Hamal 02:07:10.8 +23:27:41 2.0 10.60 135 36 Ari 02:44:19.2 +17:45:49 6.4 0.75 141 40 Ari 02:48:32.2 +18:17:00 7.3 0.44 142 PPM 118547 02:47:33.2 +18:30:37 8.8 0.33 142 12126_99RM11 02:46:42.3 +18:15:12 15.5 142 Positions are for J2000