Occultation event with (11887) Echemmon, event index number 4824
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/11/23 00:39:06 UTC
J2000 position of star is 05:39:52.8 +13:56:11
Equinox of date position of star is 05:41:24.4 +13:56:56
Star is 48 degrees from the moon. Moon is 96% illuminated.
Stellar brightness G=14.1, apparent brightess of occulting body is G=15.7
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 81% with SNR of 7.4 for the occulted depth (per occulted point)
Apparent velocity is 16.9 km/sec on the sky relative to the star, or, 20.0 arcsec/hr.
Position angle of asteroid motion is 63.7 degrees
The recommended exposure time corresponds to 5.1 km per image.
The 1-sigma error in the time of the event is 0.2 seconds.
The 1-sigma cross-track error in the shadow position is 37.7 km.
The sky-plane scale is 3047.3 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 2.4 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, (2026/11/23 00:39UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.7 +07:24:35 0.4 7.53 54 Bellatrix 05:26:34.5 +06:22:18 1.6 8.41 47 35 Ori 05:35:26.1 +14:19:19 5.6 1.49 47 PPM 121221 05:40:39.6 +14:34:11 7.5 0.65 48 PPM 121275 05:43:11.5 +13:55:55 9.3 0.43 49 PPM 121214 05:40:18.9 +13:51:44 10.2 0.28 48 11887_Echemmon 05:41:24.4 +13:56:56 15.7 49 Positions are for equinox of date
Star training set for 11887_Echemmon, (2026/11/23 00:39UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 7.53 54 Bellatrix 05:25:07.8 +06:20:58 1.6 8.41 47 35 Ori 05:33:54.3 +14:18:20 5.6 1.49 47 PPM 121221 05:39:07.6 +14:33:24 7.5 0.65 48 PPM 121275 05:41:39.9 +13:55:13 9.3 0.43 49 PPM 121214 05:38:47.4 +13:50:56 10.2 0.28 48 11887_Echemmon 05:39:52.8 +13:56:11 15.7 48 Positions are for J2000