Occultation event with (4707) Khryses, event index number 1142
Regions able to see the event: SAmericaN,SAmericaS
Geocentric closest approach at 2025/07/15 08:57:08 UTC
J2000 position of star is 03:14:43.7 +24:45:56
Equinox of date position of star is 03:16:14.1 +24:51:33
Star is 64 degrees from the moon. Moon is 78% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 4.4 per integration for unocculted signal
Expected flux drop is 68% with SNR of 3.0 for the occulted depth (per occulted point)
Apparent velocity is 29.0 km/sec on the sky relative to the star, or, 28.6 arcsec/hr.
The recommended exposure time corresponds to 10.1 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 19.3 km.
The sky-plane scale is 3645.9 km/arcsec.
Diameter estimates:
43.8 km assuming a 5% albedo, aximum of 1.5 sec for a central chord
17.9 km assuming a 30% albedo, maximum of 0.6 sec for a central chord
Cross-track diameter of 43.8 km used for deployment plan.
Star training set for 4707_Khryses, (2025/07/15 08:57UT) Object RA Dec mag sep mel Aldebaran 04:37:23.3 +16:33:31 0.8 20.68 81 44Zet Per 03:55:44.6 +31:57:26 2.8 11.21 75 52 Ari 03:06:56.9 +25:21:11 6.1 2.16 62 PPM 092328 03:17:10.3 +24:38:12 8.0 0.31 64 PPM 092318 03:16:20.2 +25:01:19 9.0 0.16 64 4707_Khryses 03:16:14.1 +24:51:33 16.0 65 Positions are for equinox of date
Star training set for 4707_Khryses, (2025/07/15 08:57UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 20.68 81 44Zet Per 03:54:07.9 +31:53:01 2.8 11.21 75 52 Ari 03:05:26.7 +25:15:19 6.1 2.16 62 PPM 092328 03:15:40.0 +24:32:37 8.0 0.31 64 PPM 092318 03:14:49.7 +24:55:42 9.0 0.16 64 4707_Khryses 03:14:43.7 +24:45:56 16.0 64 Positions are for J2000