Occultation event with (11509) Thersilochos, event index number 1101
Regions able to see the event: Australia
Geocentric closest approach at 2025/06/29 19:46:29 UTC
J2000 position of star is 03:13:52.6 +15:59:46
Equinox of date position of star is 03:15:18.3 +16:05:24
Star is 104 degrees from the moon. Moon is 22% illuminated.
Stellar brightness G=14.7, apparent brightess of occulting body is G=15.6
Use an exposure time of 0.40 seconds with the standard RECON-QHY system.
SNR of 7.3 per integration for unocculted signal
Expected flux drop is 70% with SNR of 5.1 for the occulted depth (per occulted point)
Apparent velocity is 33.3 km/sec on the sky relative to the star, or, 31.0 arcsec/hr.
The recommended exposure time corresponds to 13.3 km per image.
The 1-sigma error in the time of the event is 1.4 seconds.
The 1-sigma cross-track error in the shadow position is 4.8 km.
The sky-plane scale is 3866.4 km/arcsec.
Diameter estimates:
55.0 km assuming a 5% albedo, aximum of 1.6 sec for a central chord
22.4 km assuming a 30% albedo, maximum of 0.7 sec for a central chord
Cross-track diameter of 55.0 km used for deployment plan.
Star training set for 11509_Thersilochos, (2025/06/29 19:46UT) Object RA Dec mag sep mel Aldebaran 04:37:23.2 +16:33:30 0.8 19.69 85 Menkar 03:03:36.9 +04:11:18 2.5 12.24 110 PPM 118814 03:07:47.9 +13:17:02 5.6 3.34 106 PPM 118930 03:15:34.0 +15:41:02 7.2 0.41 104 PPM 118957 03:16:54.2 +16:00:04 9.0 0.39 104 PPM 118911 03:14:04.9 +16:14:30 10.2 0.33 104 11509_Thersilo 03:15:18.3 +16:05:24 15.6 104 Positions are for equinox of date
Star training set for 11509_Thersilochos, (2025/06/29 19:46UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 19.69 85 Menkar 03:02:16.8 +04:05:21 2.5 12.24 110 PPM 118814 03:06:23.7 +13:11:13 5.6 3.34 106 PPM 118930 03:14:08.5 +15:35:25 7.2 0.41 104 PPM 118957 03:15:28.5 +15:54:29 9.0 0.39 104 PPM 118911 03:12:39.2 +16:08:51 10.2 0.33 104 11509_Thersilo 03:13:52.6 +15:59:46 15.6 104 Positions are for J2000