Occultation event with (18054) 99SW7, event index number 1401
Regions able to see the event: SAmericaS
Geocentric closest approach at 2025/10/23 06:23:24 UTC
J2000 position of star is 03:52:21.9 -03:10:21
Equinox of date position of star is 03:53:39.6 -03:05:49
Star is 152 degrees from the moon. Moon is 3% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.60 seconds with the standard RECON-QHY system.
SNR of 3.6 per integration for unocculted signal
Expected flux drop is 50% with SNR of 1.8 for the occulted depth (per occulted point)
Apparent velocity is 15.0 km/sec on the sky relative to the star, or, 16.6 arcsec/hr.
Position angle of asteroid motion is 64.3 degrees
The recommended exposure time corresponds to 9.0 km per image.
The 1-sigma error in the time of the event is 1.5 seconds.
The 1-sigma cross-track error in the shadow position is 22.4 km.
The sky-plane scale is 3243.2 km/arcsec.
Diameter estimates:
42.9 km assuming a 5% albedo, aximum of 2.9 sec for a central chord
17.5 km assuming a 30% albedo, maximum of 1.2 sec for a central chord
Cross-track diameter of 36.2 km used for deployment plan.
Star training set for 18054_99SW7, (2025/10/23 06:23UT) Object RA Dec mag sep mel Rigel 05:15:46.8 -08:10:25 0.1 21.04 136 Menkar 03:03:37.9 +04:11:22 2.5 14.47 162 32 Eri 03:55:35.4 -02:52:46 5.0 0.53 152 PPM 186272 03:53:25.4 -03:31:17 8.0 0.43 152 PPM 186271 03:53:24.1 -03:20:27 8.7 0.25 152 18054_99SW7 03:53:39.6 -03:05:49 15.9 152 Positions are for equinox of date
Star training set for 18054_99SW7, (2025/10/23 06:23UT) Object RA Dec mag sep mel Rigel 05:14:32.3 -08:12:06 0.1 21.04 136 Menkar 03:02:16.8 +04:05:21 2.5 14.47 162 32 Eri 03:54:17.5 -02:57:14 5.0 0.53 152 PPM 186272 03:52:07.9 -03:35:50 8.0 0.43 152 PPM 186271 03:52:06.5 -03:25:00 8.7 0.25 152 18054_99SW7 03:52:21.9 -03:10:21 15.9 152 Positions are for J2000