Occultation event with (15527) 99YY2, event index number 1584
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/11/25 06:04:27 UTC
J2000 position of star is 11:16:49.1 -00:25:44
Equinox of date position of star is 11:18:08.7 -00:34:14
Star is 127 degrees from the moon. Moon is 21% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=17.3
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 4.3 per integration for unocculted signal
Expected flux drop is 84% with SNR of 3.6 for the occulted depth (per occulted point)
Apparent velocity is 19.0 km/sec on the sky relative to the star, or, 15.2 arcsec/hr.
Position angle of asteroid motion is 107.8 degrees
The recommended exposure time corresponds to 8.6 km per image.
The 1-sigma error in the time of the event is 0.6 seconds.
The 1-sigma cross-track error in the shadow position is 29.5 km.
The sky-plane scale is 4522.4 km/arcsec.
Diameter estimates:
38.7 km assuming a 5% albedo, aximum of 2.0 sec for a central chord
15.8 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 36.4 km used for deployment plan.
Star training set for 15527_99YY2, (2025/11/25 06:04UT) Object RA Dec mag sep mel Regulus 10:09:44.9 +11:50:23 1.3 21.03 148 Denebola 11:50:22.8 +14:25:38 2.1 16.99 126 69 Leo 11:15:05.1 -00:12:39 5.3 0.85 128 PPM 178456 11:20:52.7 -00:19:53 8.1 0.72 127 PPM 178442 11:18:04.5 -01:12:49 9.6 0.64 127 PPM 178439 11:17:29.4 -00:41:18 11.0 0.20 127 15527_99YY2 11:18:08.7 -00:34:14 17.3 127 Positions are for equinox of date
Star training set for 15527_99YY2, (2025/11/25 06:04UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 21.03 148 Denebola 11:49:02.7 +14:34:16 2.1 16.99 126 69 Leo 11:13:45.5 -00:04:10 5.3 0.85 128 PPM 178456 11:19:33.0 -00:11:22 8.1 0.72 127 PPM 178442 11:16:45.0 -01:04:19 9.6 0.64 127 PPM 178439 11:16:09.8 -00:32:48 11.0 0.20 127 15527_99YY2 11:16:49.1 -00:25:44 17.3 127 Positions are for J2000