Occultation event with (2241) Alcathous, event index number 1044
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/06/10 02:27:48 UTC
J2000 position of star is 01:09:25.1 +23:03:05
Equinox of date position of star is 01:10:47.7 +23:11:11
Star is 139 degrees from the moon. Moon is 98% illuminated.
Stellar brightness G=14.2, apparent brightess of occulting body is G=14.5
Use an exposure time of 0.40 seconds with the standard RECON-QHY system.
SNR of 9.5 per integration for unocculted signal
Expected flux drop is 57% with SNR of 5.4 for the occulted depth (per occulted point)
Apparent velocity is 29.6 km/sec on the sky relative to the star, or, 24.4 arcsec/hr.
The recommended exposure time corresponds to 11.9 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 23.0 km.
The sky-plane scale is 4368.9 km/arcsec.
Diameter estimates:
118.6 km assuming a 5% albedo, aximum of 4.0 sec for a central chord
48.4 km assuming a 30% albedo, maximum of 1.6 sec for a central chord
Cross-track diameter of 118.6 km used for deployment plan.
Star training set for 2241_Alcathous, (2025/06/10 02:28UT) Object RA Dec mag sep mel Aldebaran 04:37:23.0 +16:33:30 0.8 48.78 169 6Bet Ari 01:56:03.0 +20:55:53 2.6 10.72 148 74Psi1Psc 01:07:03.8 +21:36:05 5.8 1.80 137 PPM 090520 01:10:45.6 +23:02:43 7.5 0.14 139 PPM 090514 01:10:30.7 +23:17:15 9.3 0.12 139 2241_Alcathous 01:10:47.7 +23:11:11 14.5 139 Positions are for equinox of date
Star training set for 2241_Alcathous, (2025/06/10 02:28UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 48.78 169 6Bet Ari 01:54:38.6 +20:48:26 2.6 10.72 148 74Psi1Psc 01:05:41.8 +21:27:56 5.8 1.80 137 PPM 090520 01:09:23.1 +22:54:36 7.5 0.14 139 PPM 090514 01:09:08.1 +23:09:08 9.3 0.12 139 2241_Alcathous 01:09:25.1 +23:03:05 14.5 139 Positions are for J2000