Occultation event with (4707) Khryses, event index number 1689
Regions able to see the event: Europe,SAmericaN
Geocentric closest approach at 2025/12/16 22:45:44 UTC
J2000 position of star is 03:05:20.2 +25:59:49
Equinox of date position of star is 03:06:52.4 +26:05:47
Star is 176 degrees from the moon. Moon is 9% illuminated.
Stellar brightness G=14.2, apparent brightess of occulting body is G=15.3
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 9.3 per integration for unocculted signal
Expected flux drop is 73% with SNR of 6.7 for the occulted depth (per occulted point)
Apparent velocity is 11.0 km/sec on the sky relative to the star, or, 14.3 arcsec/hr.
Position angle of asteroid motion is 59.4 degrees
The recommended exposure time corresponds to 3.9 km per image.
The 1-sigma error in the time of the event is 2.2 seconds.
The 1-sigma cross-track error in the shadow position is 24.1 km.
The sky-plane scale is 2785.0 km/arcsec.
Diameter estimates:
43.8 km assuming a 5% albedo, aximum of 4.0 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, (2025/12/16 22:46UT) Object RA Dec mag sep mel Aldebaran 04:37:24.8 +16:33:34 0.8 23.09 159 44Zet Per 03:55:46.2 +31:57:31 2.8 12.18 166 52 Ari 03:06:58.4 +25:21:16 6.1 0.74 177 PPM 092198 03:07:02.9 +25:58:05 8.8 0.13 177 4707_Khryses 03:06:52.4 +26:05:47 15.3 176 Positions are for equinox of date
Star training set for 4707_Khryses, (2025/12/16 22:46UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 23.09 159 44Zet Per 03:54:07.9 +31:53:01 2.8 12.18 166 52 Ari 03:05:26.7 +25:15:19 6.1 0.74 177 PPM 092198 03:05:30.8 +25:52:07 8.8 0.13 177 4707_Khryses 03:05:20.2 +25:59:49 15.3 176 Positions are for J2000