Occultation event with (11887) Echemmon, event index number 3265
Regions able to see the event: UAE
Geocentric closest approach at 2026/02/18 18:00:01 UTC
J2000 position of star is 02:53:20.7 +18:47:50
Equinox of date position of star is 02:54:49.3 +18:54:10
Star is 61 degrees from the moon. Moon is 2% illuminated.
Stellar brightness G=12.1, apparent brightess of occulting body is G=16.3
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 20.7 per integration for unocculted signal
Expected flux drop is 98% with SNR of 20.3 for the occulted depth (per occulted point)
Apparent velocity is 20.2 km/sec on the sky relative to the star, or, 19.9 arcsec/hr.
Position angle of asteroid motion is 92.1 degrees
The recommended exposure time corresponds to 2.4 km per image.
The 1-sigma error in the time of the event is 0.3 seconds.
The 1-sigma cross-track error in the shadow position is 34.9 km.
The sky-plane scale is 3664.0 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 2.0 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 31.2 km used for deployment plan.
Star training set for 11887_Echemmon, (2026/02/18 18:00UT) Object RA Dec mag sep mel Aldebaran 04:37:25.4 +16:33:35 0.8 24.52 84 Hamal 02:08:39.2 +23:35:05 2.0 11.73 53 46Rho3Ari 02:57:55.0 +18:07:33 5.6 1.07 61 PPM 118599 02:52:11.6 +19:16:00 7.2 0.72 60 PPM 118642 02:55:15.3 +18:44:22 9.0 0.19 61 11887_Echemmon 02:54:49.3 +18:54:10 16.3 61 Positions are for equinox of date
Star training set for 11887_Echemmon, (2026/02/18 18:00UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 24.52 84 Hamal 02:07:10.8 +23:27:41 2.0 11.73 53 46Rho3Ari 02:56:26.6 +18:01:18 5.6 1.07 61 PPM 118599 02:50:42.9 +19:09:36 7.2 0.72 60 PPM 118642 02:53:46.8 +18:38:03 9.0 0.19 61 11887_Echemmon 02:53:20.7 +18:47:50 16.3 61 Positions are for J2000