Occultation event with (15663) Periphas, event index number 3696
Regions able to see the event: NZ
Geocentric closest approach at 2026/04/29 10:54:03 UTC
J2000 position of star is 12:19:17.5 -00:35:24
Equinox of date position of star is 12:20:38.5 -00:44:09
Star is 10 degrees from the moon. Moon is 95% illuminated.
Stellar brightness G=15.8, apparent brightess of occulting body is G=16.3
Use an exposure time of 0.55 seconds with the standard RECON-QHY system.
SNR of 3.6 per integration for unocculted signal
Expected flux drop is 61% with SNR of 2.2 for the occulted depth (per occulted point)
Apparent velocity is 16.4 km/sec on the sky relative to the star, or, 16.9 arcsec/hr.
Position angle of asteroid motion is 88.1 degrees
The recommended exposure time corresponds to 9.0 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 19.3 km.
The sky-plane scale is 3496.1 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 2.5 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 36.2 km used for deployment plan.
Star training set for 15663_Periphas, (2026/04/29 10:54UT) Object RA Dec mag sep mel Spica 13:26:35.0 -11:17:52 1.0 19.48 10 Vindemiatrix 13:03:29.3 +10:49:06 2.8 15.71 20 15Eta Vir 12:21:15.2 -00:48:46 3.9 0.17 10 PPM 178782 12:27:01.4 -00:25:39 8.4 1.62 9 15Eta Vir 12:21:15.2 -00:48:46 3.9 0.17 10 PPM 178750 12:20:34.8 -00:44:38 10.1 0.02 10 15663_Periphas 12:20:38.5 -00:44:09 16.3 10 Positions are for equinox of date
Star training set for 15663_Periphas, (2026/04/29 10:54UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 19.48 10 Vindemiatrix 13:02:10.1 +10:57:33 2.8 15.71 20 15Eta Vir 12:19:54.3 -00:40:01 3.9 0.17 10 PPM 178782 12:25:40.4 -00:16:55 8.4 1.62 9 15Eta Vir 12:19:54.3 -00:40:01 3.9 0.17 10 PPM 178750 12:19:13.8 -00:35:52 10.1 0.02 10 15663_Periphas 12:19:17.5 -00:35:24 16.3 10 Positions are for J2000