Occultation event with (2241) Alcathous, event index number 4324
Regions able to see the event: Australia
Geocentric closest approach at 2026/09/29 13:43:52 UTC
J2000 position of star is 03:41:42.5 +31:18:57
Equinox of date position of star is 03:43:22.7 +31:23:59
Star is 18 degrees from the moon. Moon is 90% illuminated.
Stellar brightness G=13.3, apparent brightess of occulting body is G=14.0
Use an exposure time of 0.16 seconds with the standard RECON-QHY system.
SNR of 9.8 per integration for unocculted signal
Expected flux drop is 66% with SNR of 6.4 for the occulted depth (per occulted point)
Apparent velocity is 6.0 km/sec on the sky relative to the star, or, 6.2 arcsec/hr.
Position angle of asteroid motion is 91.1 degrees
The recommended exposure time corresponds to 1.0 km per image.
The 1-sigma error in the time of the event is 0.3 seconds.
The 1-sigma cross-track error in the shadow position is 38.6 km.
The sky-plane scale is 3499.3 km/arcsec.
Diameter estimates:
118.6 km assuming a 5% albedo, maximum of 19.7 sec for a central chord
48.4 km assuming a 30% albedo, maximum of 8.0 sec for a central chord
Cross-track diameter of 113.7 km used for deployment plan.
Star training set for 2241_Alcathous, (2026/09/29 13:44UT) Object RA Dec mag sep mel Aldebaran 04:37:27.5 +16:33:39 0.8 19.27 28 44Zet Per 03:55:49.2 +31:57:39 2.8 2.71 20 38Omi Per 03:46:00.2 +32:22:15 3.7 1.12 19 PPM 068748 03:46:30.8 +30:13:06 8.3 1.36 18 PPM 068702 03:43:56.5 +31:45:35 9.5 0.38 18 PPM 068688 03:42:52.2 +31:32:01 10.4 0.17 18 2241_Alcathous 03:43:22.7 +31:23:59 14.0 18 Positions are for equinox of date
Star training set for 2241_Alcathous, (2026/09/29 13:44UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 19.27 28 44Zet Per 03:54:07.9 +31:53:01 2.8 2.71 20 38Omi Per 03:44:19.1 +32:17:17 3.7 1.12 19 PPM 068748 03:44:51.2 +30:08:10 8.3 1.36 18 PPM 068702 03:42:16.0 +31:40:34 9.5 0.38 18 PPM 068688 03:41:11.9 +31:26:58 10.4 0.17 18 2241_Alcathous 03:41:42.5 +31:18:57 14.0 18 Positions are for J2000