Occultation event with (24313) 99YR27, event index number 998
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/05/24 16:38:45 UTC
J2000 position of star is 09:37:51.3 +31:14:39
Equinox of date position of star is 09:39:21.3 +31:07:44
Star is 106 degrees from the moon. Moon is 9% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=16.7
Use an exposure time of 0.80 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 58% with SNR of 1.7 for the occulted depth (per occulted point)
Apparent velocity is 22.6 km/sec on the sky relative to the star, or, 19.9 arcsec/hr.
Position angle of asteroid motion is 312.5 degrees
The recommended exposure time corresponds to 18.1 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 41.5 km.
The sky-plane scale is 4072.1 km/arcsec.
Diameter estimates:
41.5 km assuming a 5% albedo, aximum of 1.8 sec for a central chord
16.9 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 41.5 km used for deployment plan.
Star training set for 24313_99YR27, (2025/05/24 16:39UT) Object RA Dec mag sep mel Regulus 10:09:43.3 +11:50:32 1.3 20.52 120 15 Leo 09:45:02.2 +29:51:23 5.6 1.77 107 PPM 074645 09:38:13.0 +31:02:48 7.5 0.26 105 PPM 074650 09:38:43.4 +31:08:04 9.7 0.14 105 24313_99YR27 09:39:21.3 +31:07:44 16.7 106 Positions are for equinox of date
Star training set for 24313_99YR27, (2025/05/24 16:39UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 20.52 120 15 Leo 09:43:33.2 +29:58:26 5.6 1.77 107 PPM 074645 09:36:43.0 +31:09:42 7.5 0.26 105 PPM 074650 09:37:13.3 +31:14:59 9.7 0.14 105 24313_99YR27 09:37:51.3 +31:14:39 16.7 106 Positions are for J2000