Occultation event with (3391) Sinon, event index number 3669
Regions able to see the event: Australia
Geocentric closest approach at 2026/04/21 14:42:42 UTC
J2000 position of star is 10:58:48.7 +02:35:09
Equinox of date position of star is 11:00:10.0 +02:26:40
Star is 77 degrees from the moon. Moon is 23% illuminated.
Stellar brightness G=14.9, apparent brightess of occulting body is G=15.6
Use an exposure time of 0.80 seconds with the standard RECON-QHY system.
SNR of 9.7 per integration for unocculted signal
Expected flux drop is 65% with SNR of 6.3 for the occulted depth (per occulted point)
Apparent velocity is 8.5 km/sec on the sky relative to the star, or, 9.4 arcsec/hr.
Position angle of asteroid motion is 98.6 degrees
The recommended exposure time corresponds to 6.8 km per image.
The 1-sigma error in the time of the event is 3.5 seconds.
The 1-sigma cross-track error in the shadow position is 28.3 km.
The sky-plane scale is 3256.1 km/arcsec.
Diameter estimates:
51.5 km assuming a 5% albedo, maximum of 6.1 sec for a central chord
21.0 km assuming a 30% albedo, maximum of 2.5 sec for a central chord
Cross-track diameter of 37.9 km used for deployment plan.
Star training set for 3391_Sinon, (2026/04/21 14:43UT) Object RA Dec mag sep mel Regulus 10:09:46.2 +11:50:15 1.3 15.62 61 58 Leo 11:01:55.1 +03:28:33 4.8 1.12 77 PPM 157393 11:00:08.8 +01:35:15 8.4 0.86 77 PPM 157394 11:00:21.1 +02:03:12 9.5 0.39 77 PPM 157401 11:00:41.5 +02:06:38 11.0 0.36 77 3391_Sinon 11:00:10.0 +02:26:40 15.6 77 Positions are for equinox of date
Star training set for 3391_Sinon, (2026/04/21 14:43UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 15.62 61 58 Leo 11:00:33.7 +03:37:02 4.8 1.12 77 PPM 157393 10:58:47.6 +01:43:44 8.4 0.86 77 PPM 157394 10:58:59.9 +02:11:41 9.5 0.39 77 PPM 157401 10:59:20.3 +02:15:07 11.0 0.36 77 3391_Sinon 10:58:48.7 +02:35:09 15.6 77 Positions are for J2000