Occultation event with (4707) Khryses, event index number 4047
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/08/19 09:03:07 UTC
J2000 position of star is 06:08:17.2 +28:12:09
Equinox of date position of star is 06:09:58.2 +28:11:48
Star is 137 degrees from the moon. Moon is 43% illuminated.
Stellar brightness G=13.5, apparent brightess of occulting body is G=16.2
Use an exposure time of 0.17 seconds with the standard RECON-QHY system.
SNR of 9.7 per integration for unocculted signal
Expected flux drop is 92% with SNR of 9.0 for the occulted depth (per occulted point)
Apparent velocity is 30.3 km/sec on the sky relative to the star, or, 27.9 arcsec/hr.
Position angle of asteroid motion is 89.5 degrees
The recommended exposure time corresponds to 5.1 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 34.6 km.
The sky-plane scale is 3905.1 km/arcsec.
Diameter estimates:
43.8 km assuming a 5% albedo, maximum of 1.4 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 37.8 km used for deployment plan.
Star training set for 4707_Khryses, (2026/08/19 09:03UT) Object RA Dec mag sep mel Betelgeuse 05:56:36.9 +07:24:35 0.4 21.02 135 Alnath 05:27:58.7 +28:37:38 1.6 9.24 146 PPM 095226 06:02:40.9 +27:34:17 6.0 1.73 138 PPM 095434 06:09:20.6 +27:51:16 8.4 0.37 137 PPM 095437 06:09:24.3 +28:06:31 9.7 0.15 137 PPM 095453 06:09:49.0 +28:09:17 11.7 0.05 137 4707_Khryses 06:09:58.2 +28:11:48 16.2 136 Positions are for equinox of date
Star training set for 4707_Khryses, (2026/08/19 09:03UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 21.02 135 Alnath 05:26:17.6 +28:36:22 1.6 9.24 146 PPM 095226 06:01:00.4 +27:34:21 6.0 1.73 138 PPM 095434 06:07:39.9 +27:51:36 8.4 0.37 137 PPM 095437 06:07:43.4 +28:06:51 9.7 0.15 137 PPM 095453 06:08:08.0 +28:09:38 11.7 0.05 137 4707_Khryses 06:08:17.2 +28:12:09 16.2 137 Positions are for J2000