Occultation event with (18054) 99SW7, event index number 4164
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/09/03 07:07:17 UTC
J2000 position of star is 05:47:41.4 +08:53:50
Equinox of date position of star is 05:49:09.0 +08:54:17
Star is 35 degrees from the moon. Moon is 62% illuminated.
Stellar brightness G=11.8, apparent brightess of occulting body is G=16.6
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 24.3 per integration for unocculted signal
Expected flux drop is 99% with SNR of 24.0 for the occulted depth (per occulted point)
Apparent velocity is 20.4 km/sec on the sky relative to the star, or, 18.3 arcsec/hr.
Position angle of asteroid motion is 99.2 degrees
The recommended exposure time corresponds to 2.4 km per image.
The 1-sigma error in the time of the event is 0.2 seconds.
The 1-sigma cross-track error in the shadow position is 34.4 km.
The sky-plane scale is 4008.2 km/arcsec.
Diameter estimates:
42.9 km assuming a 5% albedo, maximum of 2.1 sec for a central chord
17.5 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 36.2 km used for deployment plan.
Star training set for 18054_99SW7, (2026/09/03 07:07UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.0 +07:24:35 0.4 2.38 38 Bellatrix 05:26:33.8 +06:22:18 1.6 6.14 32 PPM 149523 05:51:30.9 +09:52:37 6.4 1.13 35 PPM 149458 05:48:50.0 +08:33:22 8.0 0.36 36 PPM 149437 05:48:13.6 +08:45:56 10.8 0.27 35 18054_99SW7 05:49:09.0 +08:54:17 16.6 36 Positions are for equinox of date
Star training set for 18054_99SW7, (2026/09/03 07:07UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 2.38 38 Bellatrix 05:25:07.8 +06:20:58 1.6 6.14 32 PPM 149523 05:50:02.7 +09:52:15 6.4 1.13 35 PPM 149458 05:47:22.6 +08:32:54 8.0 0.36 36 PPM 149437 05:46:46.1 +08:45:27 10.8 0.27 35 18054_99SW7 05:47:41.4 +08:53:50 16.6 35 Positions are for J2000