Occultation event with (11554) Asios, event index number 1373
Regions able to see the event: NZ
Geocentric closest approach at 2025/10/16 11:58:00 UTC
J2000 position of star is 03:32:01.2 +02:28:20
Equinox of date position of star is 03:33:21.7 +02:33:30
Star is 96 degrees from the moon. Moon is 23% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=15.8
Use an exposure time of 1.00 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 36% with SNR of 1.1 for the occulted depth (per occulted point)
Apparent velocity is 14.7 km/sec on the sky relative to the star, or, 15.5 arcsec/hr.
Position angle of asteroid motion is 63.5 degrees
The recommended exposure time corresponds to 14.7 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 23.6 km.
The sky-plane scale is 3409.0 km/arcsec.
Diameter estimates:
48.1 km assuming a 5% albedo, aximum of 3.3 sec for a central chord
19.6 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 41.6 km used for deployment plan.
Star training set for 11554_Asios, (2025/10/16 11:58UT) Object RA Dec mag sep mel Aldebaran 04:37:24.2 +16:33:32 0.8 21.07 77 Menkar 03:03:37.9 +04:11:22 2.5 7.60 103 12 Tau 03:41:11.9 +03:08:20 6.1 2.04 94 PPM 146682 03:35:34.6 +03:31:00 7.8 1.11 95 PPM 146639 03:32:45.9 +02:44:56 8.8 0.24 96 11554_Asios 03:33:21.7 +02:33:30 15.8 95 Positions are for equinox of date
Star training set for 11554_Asios, (2025/10/16 11:58UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 21.07 77 Menkar 03:02:16.8 +04:05:21 2.5 7.60 103 12 Tau 03:39:51.1 +03:03:25 6.1 2.04 94 PPM 146682 03:34:13.6 +03:25:54 7.8 1.11 95 PPM 146639 03:31:25.3 +02:39:45 8.8 0.24 96 11554_Asios 03:32:01.2 +02:28:20 15.8 96 Positions are for J2000