Occultation event with (17365) Thymbraeus, event index number 1169
Regions able to see the event: SAmericaN,SAmericaS
Geocentric closest approach at 2025/07/26 08:20:53 UTC
J2000 position of star is 02:31:33.2 +22:57:10
Equinox of date position of star is 02:33:00.7 +23:03:53
Star is 100 degrees from the moon. Moon is 3% illuminated.
Stellar brightness G=14.5, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 79% with SNR of 7.9 for the occulted depth (per occulted point)
Apparent velocity is 18.1 km/sec on the sky relative to the star, or, 18.2 arcsec/hr.
The recommended exposure time corresponds to 9.1 km per image.
The 1-sigma error in the time of the event is 2.4 seconds.
The 1-sigma cross-track error in the shadow position is 14.2 km.
The sky-plane scale is 3582.5 km/arcsec.
Diameter estimates:
47.2 km assuming a 5% albedo, aximum of 2.6 sec for a central chord
19.3 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 47.2 km used for deployment plan.
Star training set for 17365_Thymbraeus, (2025/07/26 08:21UT) Object RA Dec mag sep mel Aldebaran 04:37:23.4 +16:33:31 0.8 29.91 74 Hamal 02:08:37.2 +23:34:56 2.0 5.62 105 32Nu Ari 02:40:16.4 +22:04:14 5.4 1.95 99 PPM 091766 02:33:50.4 +22:26:44 7.9 0.65 100 PPM 091759 02:33:33.1 +22:56:20 9.9 0.18 100 17365_Thymbrae 02:33:00.7 +23:03:53 16.0 99 Positions are for equinox of date
Star training set for 17365_Thymbraeus, (2025/07/26 08:21UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 29.91 74 Hamal 02:07:10.8 +23:27:41 2.0 5.62 105 32Nu Ari 02:38:49.0 +21:57:41 5.4 1.95 99 PPM 091766 02:32:23.0 +22:20:02 7.9 0.65 100 PPM 091759 02:32:05.6 +22:49:37 9.9 0.18 100 17365_Thymbrae 02:31:33.2 +22:57:10 16.0 100 Positions are for J2000