Occultation event with (11509) Thersilochos, event index number 1106
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/07/01 07:25:05 UTC
J2000 position of star is 03:15:08.4 +16:01:46
Equinox of date position of star is 03:16:34.2 +16:07:22
Star is 122 degrees from the moon. Moon is 36% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=15.6
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 3.2 per integration for unocculted signal
Expected flux drop is 44% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 32.9 km/sec on the sky relative to the star, or, 30.7 arcsec/hr.
The recommended exposure time corresponds to 16.4 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 3855.1 km/arcsec.
Diameter estimates:
55.0 km assuming a 5% albedo, aximum of 1.7 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, (2025/07/01 07:25UT) Object RA Dec mag sep mel Aldebaran 04:37:23.2 +16:33:30 0.8 19.38 103 Menkar 03:03:36.9 +04:11:18 2.5 12.35 127 PPM 118814 03:07:47.9 +13:17:03 5.6 3.54 125 PPM 118930 03:15:34.0 +15:41:02 7.2 0.50 123 PPM 118957 03:16:54.2 +16:00:04 9.0 0.15 122 11509_Thersilo 03:16:34.2 +16:07:22 15.6 122 Positions are for equinox of date
Star training set for 11509_Thersilochos, (2025/07/01 07:25UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 19.38 103 Menkar 03:02:16.8 +04:05:21 2.5 12.35 127 PPM 118814 03:06:23.7 +13:11:13 5.6 3.54 125 PPM 118930 03:14:08.5 +15:35:25 7.2 0.50 123 PPM 118957 03:15:28.5 +15:54:29 9.0 0.15 122 11509_Thersilo 03:15:08.4 +16:01:46 15.6 122 Positions are for J2000