Occultation event with (15663) Periphas, event index number 3605
Regions able to see the event: Australia
Geocentric closest approach at 2026/04/09 11:56:12 UTC
J2000 position of star is 12:29:41.8 -00:39:23
Equinox of date position of star is 12:31:02.7 -00:48:05
Star is 95 degrees from the moon. Moon is 57% illuminated.
Stellar brightness G=14.9, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.40 seconds with the standard RECON-QHY system.
SNR of 6.0 per integration for unocculted signal
Expected flux drop is 73% with SNR of 4.4 for the occulted depth (per occulted point)
Apparent velocity is 20.4 km/sec on the sky relative to the star, or, 21.6 arcsec/hr.
Position angle of asteroid motion is 93.6 degrees
The recommended exposure time corresponds to 8.2 km per image.
The 1-sigma error in the time of the event is 1.4 seconds.
The 1-sigma cross-track error in the shadow position is 16.1 km.
The sky-plane scale is 3403.3 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 2.0 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 36.2 km used for deployment plan.
Star training set for 15663_Periphas, (2026/04/09 11:56UT) Object RA Dec mag sep mel Spica 13:26:34.9 -11:17:51 1.0 17.33 78 Vindemiatrix 13:03:29.1 +10:49:07 2.8 14.14 93 15Eta Vir 12:21:15.1 -00:48:45 3.9 2.45 97 PPM 178782 12:27:01.2 -00:25:38 8.4 1.07 96 PPM 178795 12:29:45.1 -01:20:38 9.6 0.63 95 PPM 178802 12:31:02.4 -00:48:06 10.7 0.00 95 15663_Periphas 12:31:02.7 -00:48:05 16.0 95 Positions are for equinox of date
Star training set for 15663_Periphas, (2026/04/09 11:56UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 17.33 78 Vindemiatrix 13:02:10.1 +10:57:33 2.8 14.14 93 15Eta Vir 12:19:54.3 -00:40:01 3.9 2.45 97 PPM 178782 12:25:40.4 -00:16:55 8.4 1.07 96 PPM 178795 12:28:24.2 -01:11:55 9.6 0.63 95 PPM 178802 12:29:41.5 -00:39:24 10.7 0.00 95 15663_Periphas 12:29:41.8 -00:39:23 16.0 95 Positions are for J2000