Occultation event with (11887) Echemmon, event index number 4740
Regions able to see the event: SAfrica
Geocentric closest approach at 2026/11/17 22:36:14 UTC
J2000 position of star is 05:42:16.3 +14:14:24
Equinox of date position of star is 05:43:48.0 +14:15:04
Star is 115 degrees from the moon. Moon is 55% illuminated.
Stellar brightness G=12.8, apparent brightess of occulting body is G=15.8
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 12.4 per integration for unocculted signal
Expected flux drop is 94% with SNR of 11.6 for the occulted depth (per occulted point)
Apparent velocity is 15.9 km/sec on the sky relative to the star, or, 18.6 arcsec/hr.
Position angle of asteroid motion is 60.9 degrees
The recommended exposure time corresponds to 1.9 km per image.
The 1-sigma error in the time of the event is 0.4 seconds.
The 1-sigma cross-track error in the shadow position is 37.4 km.
The sky-plane scale is 3070.7 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 2.6 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 31.2 km used for deployment plan.
Star training set for 11887_Echemmon, (2026/11/17 22:36UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.7 +07:24:35 0.4 7.53 117 Bellatrix 05:26:34.5 +06:22:18 1.6 8.94 110 131 Tau 05:48:45.1 +14:29:46 5.7 1.22 116 PPM 121311 05:44:29.7 +14:11:20 7.6 0.18 115 11887_Echemmon 05:43:48.0 +14:15:04 15.8 115 Positions are for equinox of date
Star training set for 11887_Echemmon, (2026/11/17 22:36UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 7.53 117 Bellatrix 05:25:07.8 +06:20:58 1.6 8.94 110 131 Tau 05:47:13.1 +14:29:18 5.7 1.22 116 PPM 121311 05:42:58.0 +14:10:42 7.6 0.18 115 11887_Echemmon 05:42:16.3 +14:14:24 15.8 115 Positions are for J2000