Occultation event with (1172) Aneas, event index number 3929
Regions able to see the event: US
Geocentric closest approach at 2026/08/03 12:15:43 UTC
J2000 position of star is 05:37:28.1 +20:40:39
Equinox of date position of star is 05:39:03.3 +20:41:30
Star is 76 degrees from the moon. Moon is 77% illuminated.
Stellar brightness G=15.1, apparent brightess of occulting body is G=14.3
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 7.6 per integration for unocculted signal
Expected flux drop is 32% with SNR of 2.4 for the occulted depth (per occulted point)
Apparent velocity is 31.9 km/sec on the sky relative to the star, or, 25.2 arcsec/hr.
Position angle of asteroid motion is 95.6 degrees
The recommended exposure time corresponds to 28.7 km per image.
The 1-sigma error in the time of the event is 0.4 seconds.
The 1-sigma cross-track error in the shadow position is 31.5 km.
The sky-plane scale is 4551.1 km/arcsec.
Diameter estimates:
138.7 km assuming a 5% albedo, maximum of 4.4 sec for a central chord
56.6 km assuming a 30% albedo, maximum of 1.8 sec for a central chord
Cross-track diameter of 118.0 km used for deployment plan.
Star training set for 1172_Aneas, (2026/08/03 12:16UT) Object RA Dec mag sep mel Betelgeuse 05:56:36.7 +07:24:35 0.4 13.94 82 Alnath 05:27:58.5 +28:37:38 1.6 8.32 74 123Zet Tau 05:39:14.1 +21:09:23 3.0 0.47 76 PPM 094568 05:38:37.5 +20:44:31 8.5 0.11 76 1172_Aneas 05:39:03.3 +20:41:30 14.3 77 Positions are for equinox of date
Star training set for 1172_Aneas, (2026/08/03 12:16UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 13.94 82 Alnath 05:26:17.6 +28:36:22 1.6 8.32 74 123Zet Tau 05:37:38.7 +21:08:33 3.0 0.47 76 PPM 094568 05:37:02.3 +20:43:39 8.5 0.11 76 1172_Aneas 05:37:28.1 +20:40:39 14.3 76 Positions are for J2000