Occultation event with (9857) Hecamede, event index number 3606
Regions able to see the event: Australia
Geocentric closest approach at 2026/04/09 12:30:14 UTC
J2000 position of star is 11:34:01.2 -22:49:40
Equinox of date position of star is 11:35:20.4 -22:58:23
Star is 96 degrees from the moon. Moon is 57% illuminated.
Stellar brightness G=14.1, apparent brightess of occulting body is G=15.3
Use an exposure time of 0.30 seconds with the standard RECON-QHY system.
SNR of 9.1 per integration for unocculted signal
Expected flux drop is 75% with SNR of 6.8 for the occulted depth (per occulted point)
Apparent velocity is 15.9 km/sec on the sky relative to the star, or, 18.4 arcsec/hr.
Position angle of asteroid motion is 121.8 degrees
The recommended exposure time corresponds to 4.8 km per image.
The 1-sigma error in the time of the event is 1.9 seconds.
The 1-sigma cross-track error in the shadow position is 14.9 km.
The sky-plane scale is 3116.9 km/arcsec.
Diameter estimates:
51.5 km assuming a 5% albedo, maximum of 3.2 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, (2026/04/09 12:30UT) Object RA Dec mag sep mel Spica 13:26:34.9 -11:17:51 1.0 28.95 78 4Gam Crv 12:17:09.7 -17:41:16 2.6 11.13 90 PPM 259219 11:38:19.1 -23:05:36 6.5 0.70 95 PPM 259140 11:34:40.0 -23:16:56 8.4 0.35 96 PPM 259148 11:34:55.5 -22:58:46 9.7 0.10 96 9857_Hecamede 11:35:20.4 -22:58:23 15.3 96 Positions are for equinox of date
Star training set for 9857_Hecamede, (2026/04/09 12:30UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 28.95 78 4Gam Crv 12:15:48.1 -17:32:30 2.6 11.13 90 PPM 259219 11:36:59.8 -22:56:52 6.5 0.70 95 PPM 259140 11:33:20.9 -23:08:13 8.4 0.35 96 PPM 259148 11:33:36.4 -22:50:03 9.7 0.10 96 9857_Hecamede 11:34:01.2 -22:49:40 15.3 96 Positions are for J2000