Occultation event with (3564) Talthybius, event index number 1031
Regions able to see the event: SAmericaS
Geocentric closest approach at 2025/06/04 22:57:58 UTC
J2000 position of star is 08:44:11.1 +31:43:27
Equinox of date position of star is 08:45:45.1 +31:37:52
Star is 61 degrees from the moon. Moon is 67% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=15.3
Use an exposure time of 1.00 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 25% with SNR of 0.8 for the occulted depth (per occulted point)
Apparent velocity is 31.7 km/sec on the sky relative to the star, or, 27.4 arcsec/hr.
Position angle of asteroid motion is 331.4 degrees
The recommended exposure time corresponds to 31.7 km per image.
The 1-sigma error in the time of the event is 1.1 seconds.
The 1-sigma cross-track error in the shadow position is 22.3 km.
The sky-plane scale is 4176.6 km/arcsec.
Diameter estimates:
76.9 km assuming a 5% albedo, aximum of 2.4 sec for a central chord
31.4 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 76.9 km used for deployment plan.
Star training set for 3564_Talthybius, (2025/06/04 22:58UT) Object RA Dec mag sep mel Pollux 07:46:52.1 +27:57:46 1.1 13.28 72 PPM 073899 08:41:52.5 +31:51:00 6.5 0.85 62 PPM 073933 08:44:20.3 +31:46:10 7.5 0.33 61 PPM 073936 08:44:25.9 +31:37:41 9.5 0.28 61 3564_Talthybiu 08:45:45.1 +31:37:52 15.3 60 Positions are for equinox of date
Star training set for 3564_Talthybius, (2025/06/04 22:58UT) Object RA Dec mag sep mel Pollux 07:45:17.8 +28:01:33 1.1 13.28 72 PPM 073899 08:40:18.2 +31:56:30 6.5 0.85 62 PPM 073933 08:42:46.2 +31:51:44 7.5 0.33 61 PPM 073936 08:42:51.9 +31:43:15 9.5 0.28 61 3564_Talthybiu 08:44:11.1 +31:43:27 15.3 61 Positions are for J2000