Occultation event with (24313) 99YR27, event index number 3323
Regions able to see the event: SMexico
Geocentric closest approach at 2026/02/27 11:51:33 UTC
J2000 position of star is 11:51:29.6 +18:17:10
Equinox of date position of star is 11:52:50.4 +18:08:26
Star is 62 degrees from the moon. Moon is 82% illuminated.
Stellar brightness G=12.6, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 14.4 per integration for unocculted signal
Expected flux drop is 96% with SNR of 13.8 for the occulted depth (per occulted point)
Apparent velocity is 17.5 km/sec on the sky relative to the star, or, 18.8 arcsec/hr.
Position angle of asteroid motion is 111.1 degrees
The recommended exposure time corresponds to 2.1 km per image.
The 1-sigma error in the time of the event is 1.9 seconds.
The 1-sigma cross-track error in the shadow position is 19.8 km.
The sky-plane scale is 3351.3 km/arcsec.
Diameter estimates:
41.9 km assuming a 5% albedo, maximum of 2.4 sec for a central chord
17.1 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 34.6 km used for deployment plan.
Star training set for 24313_99YR27, (2026/02/27 11:52UT) Object RA Dec mag sep mel Regulus 10:09:45.7 +11:50:18 1.3 25.65 42 Denebola 11:50:23.6 +14:25:33 2.1 3.76 63 PPM 128581 11:50:35.7 +16:05:49 6.3 2.11 63 PPM 128638 11:55:28.4 +18:01:26 8.0 0.64 63 PPM 128598 11:52:09.5 +18:28:48 9.1 0.38 62 PPM 128602 11:52:20.4 +17:47:39 11.1 0.37 63 24313_99YR27 11:52:50.4 +18:08:26 16.0 63 Positions are for equinox of date
Star training set for 24313_99YR27, (2026/02/27 11:52UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 25.65 42 Denebola 11:49:02.7 +14:34:16 2.1 3.76 63 PPM 128581 11:49:14.9 +16:14:33 6.3 2.11 63 PPM 128638 11:54:07.7 +18:10:10 8.0 0.64 63 PPM 128598 11:50:48.6 +18:37:32 9.1 0.38 62 PPM 128602 11:50:59.6 +17:56:22 11.1 0.37 63 24313_99YR27 11:51:29.6 +18:17:10 16.0 62 Positions are for J2000