Occultation event with (1437) Diomedes, event index number 1144
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/07/16 01:10:29 UTC
J2000 position of star is 11:20:32.5 -11:59:21
Equinox of date position of star is 11:21:49.8 -12:07:45
Star is 166 degrees from the moon. Moon is 72% illuminated.
Stellar brightness G=13.4, apparent brightess of occulting body is G=14.0
Use an exposure time of 0.17 seconds with the standard RECON-QHY system.
SNR of 9.7 per integration for unocculted signal
Expected flux drop is 63% with SNR of 6.1 for the occulted depth (per occulted point)
Apparent velocity is 26.2 km/sec on the sky relative to the star, or, 23.1 arcsec/hr.
Position angle of asteroid motion is 343.3 degrees
The recommended exposure time corresponds to 4.5 km per image.
The 1-sigma error in the time of the event is 1.4 seconds.
The 1-sigma cross-track error in the shadow position is 31.4 km.
The sky-plane scale is 4089.5 km/arcsec.
Diameter estimates:
139.3 km assuming a 5% albedo, aximum of 5.3 sec for a central chord
56.9 km assuming a 30% albedo, maximum of 2.2 sec for a central chord
Cross-track diameter of 139.3 km used for deployment plan.
Star training set for 1437_Diomedes, (2025/07/16 01:10UT) Object RA Dec mag sep mel Regulus 10:09:43.8 +11:50:29 1.3 29.91 152 4Gam Crv 12:17:07.4 -17:41:01 2.6 14.46 161 PPM 224159 11:16:56.8 -12:43:56 6.5 1.34 164 PPM 224237 11:20:10.4 -11:54:31 8.3 0.46 166 PPM 224290 11:22:12.2 -12:18:34 9.1 0.20 166 1437_Diomedes 11:21:49.8 -12:07:45 14.0 166 Positions are for equinox of date
Star training set for 1437_Diomedes, (2025/07/16 01:10UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 29.91 152 4Gam Crv 12:15:48.1 -17:32:30 2.6 14.46 161 PPM 224159 11:15:39.8 -12:35:34 6.5 1.34 164 PPM 224237 11:18:53.1 -11:46:07 8.3 0.46 166 PPM 224290 11:20:54.9 -12:10:09 9.1 0.20 166 1437_Diomedes 11:20:32.5 -11:59:21 14.0 166 Positions are for J2000