Occultation event with (17492) Hippasos, event index number 4427
Regions able to see the event: Australia
Geocentric closest approach at 2026/10/17 21:03:38 UTC
J2000 position of star is 07:13:07.2 +26:32:23
Equinox of date position of star is 07:14:46.6 +26:29:32
Star is 179 degrees from the moon. Moon is 43% illuminated.
Stellar brightness G=11.9, apparent brightess of occulting body is G=15.8
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 22.1 per integration for unocculted signal
Expected flux drop is 97% with SNR of 21.5 for the occulted depth (per occulted point)
Apparent velocity is 10.0 km/sec on the sky relative to the star, or, 9.4 arcsec/hr.
Position angle of asteroid motion is 44.5 degrees
The recommended exposure time corresponds to 1.2 km per image.
The 1-sigma error in the time of the event is 2.9 seconds.
The 1-sigma cross-track error in the shadow position is 12.6 km.
The sky-plane scale is 3831.9 km/arcsec.
Diameter estimates:
59.2 km assuming a 5% albedo, maximum of 5.9 sec for a central chord
24.1 km assuming a 30% albedo, maximum of 2.4 sec for a central chord
Cross-track diameter of 54.0 km used for deployment plan.
Star training set for 17492_Hippasos, (2026/10/17 21:04UT) Object RA Dec mag sep mel Pollux 07:46:57.2 +27:57:33 1.1 7.30 172 PPM 097053 07:09:05.5 +28:07:58 6.2 2.07 178 PPM 097190 07:14:10.6 +26:31:02 8.4 0.14 179 17492_Hippasos 07:14:46.6 +26:29:32 15.8 179 Positions are for equinox of date
Star training set for 17492_Hippasos, (2026/10/17 21:04UT) Object RA Dec mag sep mel Pollux 07:45:17.7 +28:01:33 1.1 7.30 172 PPM 097053 07:07:24.8 +28:10:36 6.2 2.07 178 PPM 097190 07:12:31.2 +26:33:51 8.4 0.14 179 17492_Hippasos 07:13:07.2 +26:32:23 15.8 179 Positions are for J2000