Occultation event with (4707) Khryses, event index number 1256
Regions able to see the event: Europe,Senegal
Geocentric closest approach at 2025/08/28 02:54:54 UTC
J2000 position of star is 03:40:10.8 +27:08:57
Equinox of date position of star is 03:41:44.1 +27:13:50
Star is 152 degrees from the moon. Moon is 22% illuminated.
Stellar brightness G=14.2, apparent brightess of occulting body is G=15.8
Use an exposure time of 0.30 seconds with the standard RECON-QHY system.
SNR of 9.0 per integration for unocculted signal
Expected flux drop is 82% with SNR of 7.4 for the occulted depth (per occulted point)
Apparent velocity is 11.2 km/sec on the sky relative to the star, or, 12.6 arcsec/hr.
Position angle of asteroid motion is 60.3 degrees
The recommended exposure time corresponds to 3.4 km per image.
The 1-sigma error in the time of the event is 2.0 seconds.
The 1-sigma cross-track error in the shadow position is 26.2 km.
The sky-plane scale is 3201.9 km/arcsec.
Diameter estimates:
43.8 km assuming a 5% albedo, aximum of 3.9 sec for a central chord
17.9 km assuming a 30% albedo, maximum of 1.6 sec for a central chord
Cross-track diameter of 37.8 km used for deployment plan.
Star training set for 4707_Khryses, (2025/08/28 02:55UT) Object RA Dec mag sep mel Aldebaran 04:37:23.8 +16:33:31 0.8 16.73 140 44Zet Per 03:55:45.1 +31:57:28 2.8 5.62 147 11 Tau 03:42:18.6 +25:24:38 6.1 1.82 152 PPM 092784 03:45:19.0 +26:27:38 8.3 1.11 151 PPM 092707 03:41:06.2 +27:18:11 8.8 0.16 152 4707_Khryses 03:41:44.1 +27:13:50 15.8 151 Positions are for equinox of date
Star training set for 4707_Khryses, (2025/08/28 02:55UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 16.73 140 44Zet Per 03:54:07.9 +31:53:01 2.8 5.62 147 11 Tau 03:40:46.3 +25:19:46 6.1 1.82 152 PPM 092784 03:43:46.0 +26:22:52 8.3 1.11 151 PPM 092707 03:39:32.8 +27:13:16 8.8 0.16 152 4707_Khryses 03:40:10.8 +27:08:57 15.8 152 Positions are for J2000