Occultation event with (9857) Hecamede, event index number 3373
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/03/08 01:52:47 UTC
J2000 position of star is 11:50:58.1 -24:12:03
Equinox of date position of star is 11:52:18.1 -24:20:48
Star is 37 degrees from the moon. Moon is 80% illuminated.
Stellar brightness G=14.9, apparent brightess of occulting body is G=15.4
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
SNR of 9.2 per integration for unocculted signal
Expected flux drop is 61% with SNR of 5.6 for the occulted depth (per occulted point)
Apparent velocity is 15.8 km/sec on the sky relative to the star, or, 18.1 arcsec/hr.
Position angle of asteroid motion is 96.4 degrees
The recommended exposure time corresponds to 11.8 km per image.
The 1-sigma error in the time of the event is 1.3 seconds.
The 1-sigma cross-track error in the shadow position is 27.2 km.
The sky-plane scale is 3141.6 km/arcsec.
Diameter estimates:
51.5 km assuming a 5% albedo, maximum of 3.3 sec for a central chord
21.0 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 49.5 km used for deployment plan.
Star training set for 9857_Hecamede, (2026/03/08 01:53UT) Object RA Dec mag sep mel Spica 13:26:34.6 -11:17:50 1.0 25.89 17 4Gam Crv 12:17:09.4 -17:41:14 2.6 8.83 31 PPM 259621 11:56:02.8 -25:51:32 5.3 1.73 36 PPM 259481 11:49:50.2 -25:13:53 8.3 1.05 37 PPM 259543 11:52:35.0 -24:26:44 9.4 0.12 37 9857_Hecamede 11:52:18.1 -24:20:48 15.4 36 Positions are for equinox of date
Star training set for 9857_Hecamede, (2026/03/08 01:53UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 25.89 17 4Gam Crv 12:15:48.1 -17:32:30 2.6 8.83 31 PPM 259621 11:54:42.6 -25:42:48 5.3 1.73 36 PPM 259481 11:48:30.5 -25:05:09 8.3 1.05 37 PPM 259543 11:51:15.0 -24:18:00 9.4 0.12 37 9857_Hecamede 11:50:58.1 -24:12:03 15.4 37 Positions are for J2000