Occultation event with (34746) Thoon, event index number 1289
Regions able to see the event: SAmericaN,SAmericaS,Senegal
Geocentric closest approach at 2025/09/16 05:04:50 UTC
J2000 position of star is 02:57:18.2 -13:54:44
Equinox of date position of star is 02:58:31.3 -13:48:36
Star is 74 degrees from the moon. Moon is 31% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=15.1
Use an exposure time of 1.35 seconds with the standard RECON-QHY system.
SNR of 4.9 per integration for unocculted signal
Expected flux drop is 29% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 11.2 km/sec on the sky relative to the star, or, 12.4 arcsec/hr.
Position angle of asteroid motion is 36.2 degrees
The recommended exposure time corresponds to 15.1 km per image.
The 1-sigma error in the time of the event is 2.0 seconds.
The 1-sigma cross-track error in the shadow position is 1.0 km.
The sky-plane scale is 3241.1 km/arcsec.
Diameter estimates:
64.0 km assuming a 5% albedo, aximum of 5.7 sec for a central chord
26.1 km assuming a 30% albedo, maximum of 2.3 sec for a central chord
Cross-track diameter of 61.7 km used for deployment plan.
Star training set for 34746_Thoon, (2025/09/16 05:05UT) Object RA Dec mag sep mel Rigel 05:15:46.5 -08:10:26 0.1 34.12 46 68Omi Cet 02:20:38.8 -02:51:44 2.0 14.40 77 PPM 212115 02:53:46.6 -12:40:01 6.0 1.62 75 PPM 212182 02:57:07.6 -13:35:54 8.1 0.40 75 PPM 212223 02:58:43.2 -13:58:38 9.9 0.17 74 34746_Thoon 02:58:31.3 -13:48:36 15.1 74 Positions are for equinox of date
Star training set for 34746_Thoon, (2025/09/16 05:05UT) Object RA Dec mag sep mel Rigel 05:14:32.3 -08:12:06 0.1 34.12 46 68Omi Cet 02:19:20.8 -02:58:46 2.0 14.40 77 PPM 212115 02:52:32.9 -12:46:16 6.0 1.62 75 PPM 212182 02:55:54.4 -13:42:03 8.1 0.40 75 PPM 212223 02:57:30.2 -14:04:46 9.9 0.17 74 34746_Thoon 02:57:18.2 -13:54:44 15.1 74 Positions are for J2000