Occultation event with (2241) Alcathous, event index number 1027
Regions able to see the event: SAmericaN,SAmericaS
Geocentric closest approach at 2025/06/03 09:48:59 UTC
J2000 position of star is 01:05:14.8 +22:28:29
Equinox of date position of star is 01:06:37.0 +22:36:38
Star is 140 degrees from the moon. Moon is 53% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=14.6
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 4.0 per integration for unocculted signal
Expected flux drop is 22% with SNR of 0.9 for the occulted depth (per occulted point)
Apparent velocity is 31.7 km/sec on the sky relative to the star, or, 25.8 arcsec/hr.
The recommended exposure time corresponds to 28.6 km per image.
The 1-sigma error in the time of the event is 1.2 seconds.
The 1-sigma cross-track error in the shadow position is 22.7 km.
The sky-plane scale is 4425.8 km/arcsec.
Diameter estimates:
118.6 km assuming a 5% albedo, aximum of 3.7 sec for a central chord
48.4 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 118.6 km used for deployment plan.
Star training set for 2241_Alcathous, (2025/06/03 09:49UT) Object RA Dec mag sep mel Aldebaran 04:37:22.9 +16:33:30 0.8 49.77 96 6Bet Ari 01:56:03.0 +20:55:52 2.6 11.60 131 74Psi1Psc 01:07:03.8 +21:36:05 5.8 1.01 140 PPM 090503 01:09:35.5 +22:06:43 7.9 0.85 140 PPM 090469 01:07:37.8 +22:41:16 9.1 0.25 139 2241_Alcathous 01:06:37.0 +22:36:38 14.6 139 Positions are for equinox of date
Star training set for 2241_Alcathous, (2025/06/03 09:49UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 49.77 96 6Bet Ari 01:54:38.6 +20:48:26 2.6 11.60 131 74Psi1Psc 01:05:41.8 +21:27:56 5.8 1.01 140 PPM 090503 01:08:13.2 +21:58:36 7.9 0.85 140 PPM 090469 01:06:15.6 +22:33:08 9.1 0.25 139 2241_Alcathous 01:05:14.8 +22:28:29 14.6 140 Positions are for J2000