Occultation event with (2241) Alcathous, event index number 3913
Regions able to see the event: Australia
Geocentric closest approach at 2026/07/30 19:26:53 UTC
J2000 position of star is 03:29:23.4 +29:48:50
Equinox of date position of star is 03:31:01.3 +29:54:14
Star is 96 degrees from the moon. Moon is 99% illuminated.
Stellar brightness G=11.9, apparent brightess of occulting body is G=14.5
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 22.4 per integration for unocculted signal
Expected flux drop is 92% with SNR of 20.5 for the occulted depth (per occulted point)
Apparent velocity is 21.8 km/sec on the sky relative to the star, or, 18.9 arcsec/hr.
Position angle of asteroid motion is 70.5 degrees
The recommended exposure time corresponds to 2.6 km per image.
The 1-sigma error in the time of the event is 0.6 seconds.
The 1-sigma cross-track error in the shadow position is 35.8 km.
The sky-plane scale is 4158.4 km/arcsec.
Diameter estimates:
118.6 km assuming a 5% albedo, maximum of 5.4 sec for a central chord
48.4 km assuming a 30% albedo, maximum of 2.2 sec for a central chord
Cross-track diameter of 113.7 km used for deployment plan.
Star training set for 2241_Alcathous, (2026/07/30 19:27UT) Object RA Dec mag sep mel Aldebaran 04:37:26.9 +16:33:38 0.8 20.22 108 44Zet Per 03:55:48.6 +31:57:37 2.8 5.70 102 PPM 092402 03:21:57.3 +29:08:34 4.5 2.11 94 PPM 068517 03:31:54.4 +30:07:50 7.7 0.30 96 2241_Alcathous 03:31:01.3 +29:54:14 14.5 97 Positions are for equinox of date
Star training set for 2241_Alcathous, (2026/07/30 19:27UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 20.22 108 44Zet Per 03:54:07.9 +31:53:01 2.8 5.70 102 PPM 092402 03:20:20.3 +29:02:54 4.5 2.11 94 PPM 068517 03:30:16.3 +30:02:28 7.7 0.30 96 2241_Alcathous 03:29:23.4 +29:48:50 14.5 96 Positions are for J2000