Occultation event with (11887) Echemmon, event index number 4660
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/11/13 01:53:04 UTC
J2000 position of star is 05:44:19.4 +14:32:10
Equinox of date position of star is 05:45:51.4 +14:32:45
Star is 166 degrees from the moon. Moon is 13% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 5.8 per integration for unocculted signal
Expected flux drop is 65% with SNR of 3.8 for the occulted depth (per occulted point)
Apparent velocity is 14.7 km/sec on the sky relative to the star, or, 17.1 arcsec/hr.
Position angle of asteroid motion is 57.4 degrees
The recommended exposure time corresponds to 7.3 km per image.
The 1-sigma error in the time of the event is 0.5 seconds.
The 1-sigma cross-track error in the shadow position is 36.4 km.
The sky-plane scale is 3097.8 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 2.8 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 31.2 km used for deployment plan.
Star training set for 11887_Echemmon, (2026/11/13 01:53UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.6 +07:24:35 0.4 7.61 160 Bellatrix 05:26:34.4 +06:22:18 1.6 9.45 156 131 Tau 05:48:45.0 +14:29:46 5.7 0.70 166 PPM 121311 05:44:29.7 +14:11:20 7.6 0.49 165 PPM 121343 05:46:16.5 +14:35:07 8.9 0.11 166 11887_Echemmon 05:45:51.4 +14:32:45 15.9 166 Positions are for equinox of date
Star training set for 11887_Echemmon, (2026/11/13 01:53UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 7.61 160 Bellatrix 05:25:07.8 +06:20:58 1.6 9.45 156 131 Tau 05:47:13.1 +14:29:18 5.7 0.70 166 PPM 121311 05:42:58.0 +14:10:42 7.6 0.49 165 PPM 121343 05:44:44.5 +14:34:33 8.9 0.11 166 11887_Echemmon 05:44:19.4 +14:32:10 15.9 166 Positions are for J2000