Occultation event with (4834) Thoas, event index number 3814
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/06/30 00:56:06 UTC
J2000 position of star is 12:24:05.0 +26:17:32
Equinox of date position of star is 12:25:24.6 +26:08:44
Star is 105 degrees from the moon. Moon is 100% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=15.0
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
SNR of 3.3 per integration for unocculted signal
Expected flux drop is 27% with SNR of 0.9 for the occulted depth (per occulted point)
Apparent velocity is 23.6 km/sec on the sky relative to the star, or, 21.2 arcsec/hr.
Position angle of asteroid motion is 151.1 degrees
The recommended exposure time corresponds to 17.7 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 1.4 km.
The sky-plane scale is 4012.4 km/arcsec.
Diameter estimates:
89.1 km assuming a 5% albedo, maximum of 3.8 sec for a central chord
36.4 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 72.3 km used for deployment plan.
Star training set for 4834_Thoas, (2026/06/30 00:56UT) Object RA Dec mag sep mel Arcturus 14:16:52.3 +19:02:46 0.0 26.63 79 Denebola 11:50:24.6 +14:25:26 2.1 14.30 108 13 Com 12:25:38.1 +25:57:07 5.2 0.20 105 PPM 101866 12:25:23.0 +25:42:16 6.7 0.44 105 13 Com 12:25:38.1 +25:57:07 5.2 0.20 105 4834_Thoas 12:25:24.6 +26:08:44 15.0 104 Positions are for equinox of date
Star training set for 4834_Thoas, (2026/06/30 00:56UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 26.63 79 Denebola 11:49:02.7 +14:34:16 2.1 14.30 108 13 Com 12:24:18.5 +26:05:55 5.2 0.20 105 PPM 101866 12:24:03.4 +25:51:04 6.7 0.44 105 13 Com 12:24:18.5 +26:05:55 5.2 0.20 105 4834_Thoas 12:24:05.0 +26:17:32 15.0 105 Positions are for J2000