Occultation event with (1172) Aneas, event index number 4084
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/08/23 10:01:08 UTC
J2000 position of star is 05:50:26.1 +20:16:41
Equinox of date position of star is 05:52:01.1 +20:17:01
Star is 169 degrees from the moon. Moon is 79% illuminated.
Stellar brightness G=15.6, apparent brightess of occulting body is G=14.3
Use an exposure time of 1.15 seconds with the standard RECON-QHY system.
SNR of 6.0 per integration for unocculted signal
Expected flux drop is 23% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 25.2 km/sec on the sky relative to the star, or, 20.7 arcsec/hr.
Position angle of asteroid motion is 99.9 degrees
The recommended exposure time corresponds to 28.9 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 30.4 km.
The sky-plane scale is 4373.4 km/arcsec.
Diameter estimates:
138.7 km assuming a 5% albedo, maximum of 5.5 sec for a central chord
56.6 km assuming a 30% albedo, maximum of 2.3 sec for a central chord
Cross-track diameter of 118.0 km used for deployment plan.
Star training set for 1172_Aneas, (2026/08/23 10:01UT) Object RA Dec mag sep mel Betelgeuse 05:56:36.9 +07:24:35 0.4 12.92 158 Alnath 05:27:58.7 +28:37:39 1.6 9.97 166 PPM 121513 05:53:58.2 +19:52:20 6.4 0.62 169 PPM 094952 05:52:04.9 +20:26:59 8.9 0.17 169 1172_Aneas 05:52:01.1 +20:17:01 14.3 169 Positions are for equinox of date
Star training set for 1172_Aneas, (2026/08/23 10:01UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 12.92 158 Alnath 05:26:17.6 +28:36:22 1.6 9.97 166 PPM 121513 05:52:23.4 +19:52:04 6.4 0.62 169 PPM 094952 05:50:29.7 +20:26:39 8.9 0.17 169 1172_Aneas 05:50:26.1 +20:16:41 14.3 169 Positions are for J2000