Occultation event with (4834) Thoas, event index number 3675
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/04/22 22:57:16 UTC
J2000 position of star is 12:29:59.8 +32:26:49
Equinox of date position of star is 12:31:17.8 +32:18:07
Star is 66 degrees from the moon. Moon is 37% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=14.5
Use an exposure time of 1.30 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 14% with SNR of 0.4 for the occulted depth (per occulted point)
Apparent velocity is 14.9 km/sec on the sky relative to the star, or, 15.9 arcsec/hr.
Position angle of asteroid motion is 71.6 degrees
The recommended exposure time corresponds to 19.3 km per image.
The 1-sigma error in the time of the event is 0.5 seconds.
The 1-sigma cross-track error in the shadow position is 37.2 km.
The sky-plane scale is 3364.6 km/arcsec.
Diameter estimates:
89.1 km assuming a 5% albedo, maximum of 6.0 sec for a central chord
36.4 km assuming a 30% albedo, maximum of 2.5 sec for a central chord
Cross-track diameter of 72.3 km used for deployment plan.
Star training set for 4834_Thoas, (2026/04/22 22:57UT) Object RA Dec mag sep mel Arcturus 14:16:51.8 +19:02:49 0.0 27.12 93 Denebola 11:50:24.0 +14:25:30 2.1 20.16 64 PPM 076567 12:34:56.4 +33:06:09 5.4 1.11 67 PPM 076537 12:32:48.5 +32:52:10 7.5 0.65 67 PPM 076493 12:29:09.0 +32:19:37 9.8 0.45 66 4834_Thoas 12:31:17.8 +32:18:07 14.5 67 Positions are for equinox of date
Star training set for 4834_Thoas, (2026/04/22 22:57UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 27.12 93 Denebola 11:49:02.7 +14:34:16 2.1 20.16 64 PPM 076567 12:33:39.0 +33:14:50 5.4 1.11 67 PPM 076537 12:31:30.8 +33:00:52 7.5 0.65 67 PPM 076493 12:27:50.9 +32:28:20 9.8 0.45 66 4834_Thoas 12:29:59.8 +32:26:49 14.5 66 Positions are for J2000