Occultation event with (4946) Askalaphus, event index number 928
Regions able to see the event: Europe
Geocentric closest approach at 2025/04/24 19:53:49 UTC
J2000 position of star is 08:14:19.1 +40:43:35
Equinox of date position of star is 08:16:01.1 +40:38:53
Star is 121 degrees from the moon. Moon is 13% illuminated.
Stellar brightness G=12.1, apparent brightess of occulting body is G=16.1
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 19.8 per integration for unocculted signal
Expected flux drop is 97% with SNR of 19.3 for the occulted depth (per occulted point)
Apparent velocity is 17.4 km/sec on the sky relative to the star, or, 15.6 arcsec/hr.
The recommended exposure time corresponds to 2.1 km per image.
The 1-sigma error in the time of the event is 2.9 seconds.
The 1-sigma cross-track error in the shadow position is 34.2 km.
The sky-plane scale is 4014.2 km/arcsec.
Diameter estimates:
55.2 km assuming a 5% albedo, aximum of 3.2 sec for a central chord
22.5 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 55.2 km used for deployment plan.
Star training set for 4946_Askalaphus, (2025/04/24 19:54UT) Object RA Dec mag sep mel Pollux 07:46:51.7 +27:57:47 1.1 14.03 120 28 Lyn 08:08:54.7 +43:11:08 6.4 2.86 119 PPM 050422 08:15:26.8 +40:38:09 8.5 0.11 121 4946_Askalaphu 08:16:01.1 +40:38:53 16.1 122 Positions are for equinox of date
Star training set for 4946_Askalaphus, (2025/04/24 19:54UT) Object RA Dec mag sep mel Pollux 07:45:17.8 +28:01:33 1.1 14.03 120 28 Lyn 08:07:09.9 +43:15:36 6.4 2.86 119 PPM 050422 08:13:44.7 +40:42:50 8.5 0.11 121 4946_Askalaphu 08:14:19.1 +40:43:35 16.1 121 Positions are for J2000