Occultation event with (1647) Menelaus, event index number 931
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/04/28 00:39:15 UTC
J2000 position of star is 08:14:21.7 +14:16:58
Equinox of date position of star is 08:15:46.7 +14:12:16
Star is 82 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=15.3, apparent brightess of occulting body is G=16.1
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
SNR of 6.9 per integration for unocculted signal
Expected flux drop is 67% with SNR of 4.6 for the occulted depth (per occulted point)
Apparent velocity is 15.3 km/sec on the sky relative to the star, or, 14.9 arcsec/hr.
Position angle of asteroid motion is 354.1 degrees
The recommended exposure time corresponds to 11.5 km per image.
The 1-sigma error in the time of the event is 2.6 seconds.
The 1-sigma cross-track error in the shadow position is 11.5 km.
The sky-plane scale is 3700.9 km/arcsec.
Diameter estimates:
47.9 km assuming a 5% albedo, aximum of 3.1 sec for a central chord
19.5 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 47.9 km used for deployment plan.
Star training set for 1647_Menelaus, (2025/04/28 00:39UT) Object RA Dec mag sep mel Pollux 07:46:51.7 +27:57:47 1.1 15.31 72 PPM 124962 08:12:24.1 +14:33:10 6.3 0.89 81 PPM 124993 08:14:02.1 +14:30:39 8.3 0.52 81 PPM 125015 08:15:03.3 +13:47:20 9.9 0.45 82 1647_Menelaus 08:15:46.7 +14:12:16 16.1 82 Positions are for equinox of date
Star training set for 1647_Menelaus, (2025/04/28 00:39UT) Object RA Dec mag sep mel Pollux 07:45:17.8 +28:01:33 1.1 15.31 72 PPM 124962 08:10:58.8 +14:37:46 6.3 0.89 81 PPM 124993 08:12:36.9 +14:35:18 8.3 0.52 81 PPM 125015 08:13:38.5 +13:52:00 9.9 0.45 82 1647_Menelaus 08:14:21.7 +14:16:58 16.1 82 Positions are for J2000