Occultation event with (17365) Thymbraeus, event index number 3916
Regions able to see the event: Australia
Geocentric closest approach at 2026/07/31 18:49:58 UTC
J2000 position of star is 04:50:51.9 +23:51:28
Equinox of date position of star is 04:52:28.6 +23:54:05
Star is 101 degrees from the moon. Moon is 95% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=16.2
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 55% with SNR of 1.7 for the occulted depth (per occulted point)
Apparent velocity is 30.2 km/sec on the sky relative to the star, or, 27.1 arcsec/hr.
Position angle of asteroid motion is 87.4 degrees
The recommended exposure time corresponds to 15.1 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 42.7 km.
The sky-plane scale is 4013.5 km/arcsec.
Diameter estimates:
47.2 km assuming a 5% albedo, maximum of 1.6 sec for a central chord
19.3 km assuming a 30% albedo, maximum of 0.6 sec for a central chord
Cross-track diameter of 44.9 km used for deployment plan.
Star training set for 17365_Thymbraeus, (2026/07/31 18:50UT) Object RA Dec mag sep mel Aldebaran 04:37:26.9 +16:33:38 0.8 8.14 96 Alnath 05:27:58.5 +28:37:38 1.6 9.25 109 PPM 093742 04:47:19.0 +23:40:29 6.1 1.20 100 PPM 093861 04:55:20.6 +23:35:46 8.5 0.72 101 PPM 093837 04:53:59.3 +23:47:39 9.9 0.36 101 PPM 093820 04:52:37.6 +24:09:58 10.5 0.27 101 17365_Thymbrae 04:52:28.6 +23:54:05 16.2 101 Positions are for equinox of date
Star training set for 17365_Thymbraeus, (2026/07/31 18:50UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 8.14 96 Alnath 05:26:17.6 +28:36:22 1.6 9.25 109 PPM 093742 04:45:42.5 +23:37:41 6.1 1.20 100 PPM 093861 04:53:44.0 +23:33:16 8.5 0.72 101 PPM 093837 04:52:22.5 +23:45:06 9.9 0.36 101 PPM 093820 04:51:00.6 +24:07:22 10.5 0.27 101 17365_Thymbrae 04:50:51.9 +23:51:28 16.2 101 Positions are for J2000