Occultation event with (11887) Echemmon, event index number 4593
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/11/07 09:21:53 UTC
J2000 position of star is 05:46:23.4 +14:53:14
Equinox of date position of star is 05:47:55.5 +14:53:45
Star is 115 degrees from the moon. Moon is 4% illuminated.
Stellar brightness G=14.8, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.55 seconds with the standard RECON-QHY system.
SNR of 8.2 per integration for unocculted signal
Expected flux drop is 73% with SNR of 6.0 for the occulted depth (per occulted point)
Apparent velocity is 13.2 km/sec on the sky relative to the star, or, 15.1 arcsec/hr.
Position angle of asteroid motion is 52.1 degrees
The recommended exposure time corresponds to 7.2 km per image.
The 1-sigma error in the time of the event is 0.8 seconds.
The 1-sigma cross-track error in the shadow position is 36.0 km.
The sky-plane scale is 3134.9 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 3.1 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 31.2 km used for deployment plan.
Star training set for 11887_Echemmon, (2026/11/07 09:22UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.6 +07:24:35 0.4 7.78 112 Bellatrix 05:26:34.4 +06:22:18 1.6 10.01 119 131 Tau 05:48:45.0 +14:29:46 5.7 0.45 115 PPM 121403 05:49:12.4 +15:02:19 8.0 0.34 115 PPM 121366 05:47:12.4 +14:41:47 9.2 0.26 115 11887_Echemmon 05:47:55.5 +14:53:45 15.9 115 Positions are for equinox of date
Star training set for 11887_Echemmon, (2026/11/07 09:22UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 7.78 112 Bellatrix 05:25:07.8 +06:20:58 1.6 10.01 119 131 Tau 05:47:13.1 +14:29:18 5.7 0.45 115 PPM 121403 05:47:40.2 +15:01:52 8.0 0.34 115 PPM 121366 05:45:40.5 +14:41:15 9.2 0.26 115 11887_Echemmon 05:46:23.4 +14:53:14 15.9 115 Positions are for J2000