Occultation event with (2241) Alcathous, event index number 1011
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/05/29 03:37:18 UTC
J2000 position of star is 01:01:47.5 +22:00:51
Equinox of date position of star is 01:03:09.4 +22:09:02
Star is 73 degrees from the moon. Moon is 6% illuminated.
Stellar brightness G=14.7, apparent brightess of occulting body is G=14.5
Use an exposure time of 0.70 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 48% with SNR of 4.7 for the occulted depth (per occulted point)
Apparent velocity is 33.3 km/sec on the sky relative to the star, or, 26.8 arcsec/hr.
The recommended exposure time corresponds to 23.3 km per image.
The 1-sigma error in the time of the event is 1.1 seconds.
The 1-sigma cross-track error in the shadow position is 23.2 km.
The sky-plane scale is 4467.3 km/arcsec.
Diameter estimates:
118.6 km assuming a 5% albedo, aximum of 3.6 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, (2025/05/29 03:37UT) Object RA Dec mag sep mel Aldebaran 04:37:22.9 +16:33:30 0.8 50.59 28 6Bet Ari 01:56:02.9 +20:55:52 2.6 12.36 62 PPM 090348 00:59:40.4 +21:32:28 6.4 1.01 74 PPM 090385 01:01:49.6 +21:23:08 7.8 0.82 73 PPM 090424 01:04:49.1 +21:56:28 9.2 0.44 72 PPM 090379 01:01:27.5 +22:02:53 11.0 0.41 73 2241_Alcathous 01:03:09.4 +22:09:02 14.5 72 Positions are for equinox of date
Star training set for 2241_Alcathous, (2025/05/29 03:37UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 50.59 28 6Bet Ari 01:54:38.6 +20:48:26 2.6 12.36 62 PPM 090348 00:58:18.9 +21:24:16 6.4 1.01 74 PPM 090385 01:00:28.0 +21:14:57 7.8 0.82 73 PPM 090424 01:03:27.2 +21:48:19 9.2 0.44 72 PPM 090379 01:00:05.8 +21:54:41 11.0 0.41 73 2241_Alcathous 01:01:47.5 +22:00:51 14.5 73 Positions are for J2000