Occultation event with (1437) Diomedes, event index number 3624
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/04/13 07:33:19 UTC
J2000 position of star is 13:11:39.8 -33:36:02
Equinox of date position of star is 13:13:07.9 -33:44:22
Star is 116 degrees from the moon. Moon is 21% illuminated.
Stellar brightness G=15.3, apparent brightess of occulting body is G=13.2
Use an exposure time of 1.70 seconds with the standard RECON-QHY system.
SNR of 6.9 per integration for unocculted signal
Expected flux drop is 13% with SNR of 0.9 for the occulted depth (per occulted point)
Apparent velocity is 17.0 km/sec on the sky relative to the star, or, 19.1 arcsec/hr.
Position angle of asteroid motion is 105.0 degrees
The recommended exposure time corresponds to 28.9 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 24.6 km.
The sky-plane scale is 3207.3 km/arcsec.
Diameter estimates:
140.6 km assuming a 5% albedo, maximum of 8.3 sec for a central chord
57.4 km assuming a 30% albedo, maximum of 3.4 sec for a central chord
Cross-track diameter of 117.8 km used for deployment plan.
Star training set for 1437_Diomedes, (2026/04/13 07:33UT) Object RA Dec mag sep mel Spica 13:26:34.9 -11:17:52 1.0 22.65 125 Iot Cen 13:22:05.0 -36:51:00 2.8 3.61 113 PPM 290865 13:02:30.1 -33:45:54 6.3 2.21 118 PPM 291027 13:10:28.6 -33:38:28 7.4 0.56 117 PPM 291067 13:12:23.1 -33:51:42 9.9 0.20 116 1437_Diomedes 13:13:07.9 -33:44:22 13.2 116 Positions are for equinox of date
Star training set for 1437_Diomedes, (2026/04/13 07:33UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 22.65 125 Iot Cen 13:20:35.1 -36:42:46 2.8 3.61 113 PPM 290865 13:01:03.1 -33:37:26 6.3 2.21 118 PPM 291027 13:09:00.8 -33:30:06 7.4 0.56 117 PPM 291067 13:10:55.0 -33:43:20 9.9 0.20 116 1437_Diomedes 13:11:39.8 -33:36:02 13.2 116 Positions are for J2000