Occultation event with (11509) Thersilochos, event index number 4845
Regions able to see the event: Europe
Geocentric closest approach at 2026/11/24 04:43:57 UTC
J2000 position of star is 06:07:08.4 +05:50:58
Equinox of date position of star is 06:08:34.8 +05:50:39
Star is 42 degrees from the moon. Moon is 100% illuminated.
Stellar brightness G=14.2, apparent brightess of occulting body is G=15.3
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 9.2 per integration for unocculted signal
Expected flux drop is 73% with SNR of 6.7 for the occulted depth (per occulted point)
Apparent velocity is 15.3 km/sec on the sky relative to the star, or, 17.3 arcsec/hr.
Position angle of asteroid motion is 65.3 degrees
The recommended exposure time corresponds to 5.4 km per image.
The 1-sigma error in the time of the event is 0.5 seconds.
The 1-sigma cross-track error in the shadow position is 28.8 km.
The sky-plane scale is 3194.5 km/arcsec.
Diameter estimates:
55.0 km assuming a 5% albedo, maximum of 3.6 sec for a central chord
22.4 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 50.0 km used for deployment plan.
Star training set for 11509_Thersilochos, (2026/11/24 04:44UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.7 +07:24:35 0.4 3.36 39 Bellatrix 05:26:34.5 +06:22:18 1.6 10.45 33 63 Ori 06:06:24.3 +05:24:58 6.4 0.69 42 PPM 149889 06:07:34.3 +06:01:10 8.0 0.31 42 PPM 149921 06:08:37.4 +05:43:52 9.2 0.11 42 11509_Thersilo 06:08:34.8 +05:50:39 15.3 42 Positions are for equinox of date
Star training set for 11509_Thersilochos, (2026/11/24 04:44UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 3.36 39 Bellatrix 05:25:07.8 +06:20:58 1.6 10.45 33 63 Ori 06:04:58.1 +05:25:12 6.4 0.69 42 PPM 149889 06:06:07.8 +06:01:26 8.0 0.31 42 PPM 149921 06:07:11.0 +05:44:10 9.2 0.11 42 11509_Thersilo 06:07:08.4 +05:50:58 15.3 42 Positions are for J2000