Occultation event with (4068) Menestheus, event index number 1077
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/06/20 23:17:22 UTC
J2000 position of star is 08:57:59.0 +07:57:54
Equinox of date position of star is 08:59:20.7 +07:51:55
Star is 106 degrees from the moon. Moon is 26% illuminated.
Stellar brightness G=15.7, apparent brightess of occulting body is G=15.1
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 3.4 per integration for unocculted signal
Expected flux drop is 36% with SNR of 1.2 for the occulted depth (per occulted point)
Apparent velocity is 34.9 km/sec on the sky relative to the star, or, 32.0 arcsec/hr.
Position angle of asteroid motion is 354.6 degrees
The recommended exposure time corresponds to 17.4 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 5.6 km.
The sky-plane scale is 3917.4 km/arcsec.
Diameter estimates:
71.1 km assuming a 5% albedo, aximum of 2.0 sec for a central chord
29.0 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 71.1 km used for deployment plan.
Star training set for 4068_Menestheus, (2025/06/20 23:17UT) Object RA Dec mag sep mel Regulus 10:09:43.5 +11:50:30 1.3 17.78 121 16Zet Hya 08:56:44.3 +05:50:50 3.1 2.12 106 PPM 155267 09:00:07.3 +08:07:25 7.6 0.32 107 PPM 155248 08:59:10.7 +07:51:52 9.0 0.04 106 4068_Menestheu 08:59:20.7 +07:51:55 15.1 107 Positions are for equinox of date
Star training set for 4068_Menestheus, (2025/06/20 23:17UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 17.78 121 16Zet Hya 08:55:23.5 +05:56:44 3.1 2.12 106 PPM 155267 08:58:45.5 +08:13:25 7.6 0.32 107 PPM 155248 08:57:49.0 +07:57:51 9.0 0.04 106 4068_Menestheu 08:57:59.0 +07:57:54 15.1 106 Positions are for J2000