Occultation event with (4836) Medon, event index number 3894
Regions able to see the event: Australia
Geocentric closest approach at 2026/07/27 13:10:24 UTC
J2000 position of star is 13:27:45.6 +07:09:53
Equinox of date position of star is 13:29:05.7 +07:01:40
Star is 85 degrees from the moon. Moon is 96% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=15.2
Use an exposure time of 1.00 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 25% with SNR of 0.8 for the occulted depth (per occulted point)
Apparent velocity is 23.5 km/sec on the sky relative to the star, or, 21.8 arcsec/hr.
Position angle of asteroid motion is 135.7 degrees
The recommended exposure time corresponds to 23.5 km per image.
The 1-sigma error in the time of the event is 1.5 seconds.
The 1-sigma cross-track error in the shadow position is 8.3 km.
The sky-plane scale is 3881.4 km/arcsec.
Diameter estimates:
74.1 km assuming a 5% albedo, maximum of 3.2 sec for a central chord
30.3 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 63.3 km used for deployment plan.
Star training set for 4836_Medon, (2026/07/27 13:10UT) Object RA Dec mag sep mel Arcturus 14:16:52.5 +19:02:45 0.0 16.71 81 Vindemiatrix 13:03:30.0 +10:49:01 2.8 7.37 93 PPM 159803 13:31:20.1 +07:02:32 6.2 0.56 85 PPM 159783 13:30:14.1 +07:18:15 9.9 0.40 85 PPM 159760 13:28:22.5 +07:12:25 10.8 0.25 86 4836_Medon 13:29:05.7 +07:01:40 15.2 85 Positions are for equinox of date
Star training set for 4836_Medon, (2026/07/27 13:10UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 16.71 81 Vindemiatrix 13:02:10.1 +10:57:33 2.8 7.37 93 PPM 159803 13:30:00.1 +07:10:44 6.2 0.56 85 PPM 159783 13:28:54.1 +07:26:27 9.9 0.40 85 PPM 159760 13:27:02.5 +07:20:39 10.8 0.25 86 4836_Medon 13:27:45.6 +07:09:53 15.2 85 Positions are for J2000