Occultation event with (4707) Khryses, event index number 4264
Regions able to see the event: Europe
Geocentric closest approach at 2026/09/19 02:38:57 UTC
J2000 position of star is 06:30:03.8 +28:13:15
Equinox of date position of star is 06:31:45.0 +28:12:03
Star is 172 degrees from the moon. Moon is 52% illuminated.
Stellar brightness G=16.0, apparent brightess of occulting body is G=16.1
Use an exposure time of 0.55 seconds with the standard RECON-QHY system.
SNR of 3.2 per integration for unocculted signal
Expected flux drop is 54% with SNR of 1.7 for the occulted depth (per occulted point)
Apparent velocity is 18.2 km/sec on the sky relative to the star, or, 18.2 arcsec/hr.
Position angle of asteroid motion is 89.6 degrees
The recommended exposure time corresponds to 10.0 km per image.
The 1-sigma error in the time of the event is 0.3 seconds.
The 1-sigma cross-track error in the shadow position is 34.9 km.
The sky-plane scale is 3610.4 km/arcsec.
Diameter estimates:
43.8 km assuming a 5% albedo, maximum of 2.4 sec for a central chord
17.9 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 37.8 km used for deployment plan.
Star training set for 4707_Khryses, (2026/09/19 02:39UT) Object RA Dec mag sep mel Pollux 07:46:56.9 +27:57:34 1.1 16.57 156 Alhena 06:39:15.3 +16:22:27 1.9 11.95 165 49 Aur 06:36:53.0 +27:59:56 5.0 1.15 171 PPM 096080 06:32:03.2 +28:11:30 7.2 0.07 172 4707_Khryses 06:31:45.0 +28:12:03 16.1 172 Positions are for equinox of date
Star training set for 4707_Khryses, (2026/09/19 02:39UT) Object RA Dec mag sep mel Pollux 07:45:17.7 +28:01:33 1.1 16.57 156 Alhena 06:37:42.8 +16:23:56 1.9 11.95 165 49 Aur 06:35:12.1 +28:01:20 5.0 1.15 171 PPM 096080 06:30:22.0 +28:12:43 7.2 0.07 172 4707_Khryses 06:30:03.8 +28:13:15 16.1 172 Positions are for J2000