Occultation event with (18493) Demoleon, event index number 1081
Regions able to see the event: SAmericaN,SAmericaS
Geocentric closest approach at 2025/06/21 09:14:17 UTC
J2000 position of star is 01:47:08.1 +15:34:29
Equinox of date position of star is 01:48:30.7 +15:42:04
Star is 4 degrees from the moon. Moon is 22% illuminated.
Stellar brightness G=15.8, apparent brightess of occulting body is G=16.6
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 66% with SNR of 2.1 for the occulted depth (per occulted point)
Apparent velocity is 27.4 km/sec on the sky relative to the star, or, 24.6 arcsec/hr.
The recommended exposure time corresponds to 12.3 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 13.4 km.
The sky-plane scale is 4020.3 km/arcsec.
Diameter estimates:
40.5 km assuming a 5% albedo, aximum of 1.5 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 0.6 sec for a central chord
Cross-track diameter of 40.5 km used for deployment plan.
Star training set for 18493_Demoleon, (2025/06/21 09:14UT) Object RA Dec mag sep mel Aldebaran 04:37:23.1 +16:33:30 0.8 40.49 36 6Bet Ari 01:56:03.2 +20:55:53 2.6 5.53 5 101 Psc 01:37:08.3 +14:47:27 5.9 2.89 7 PPM 117698 01:50:17.5 +16:30:11 7.5 0.91 4 PPM 117644 01:46:53.7 +16:23:35 9.8 0.79 4 PPM 117656 01:47:48.3 +15:50:23 10.1 0.22 4 18493_Demoleon 01:48:30.7 +15:42:04 16.6 4 Positions are for equinox of date
Star training set for 18493_Demoleon, (2025/06/21 09:14UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 40.49 36 6Bet Ari 01:54:38.6 +20:48:26 2.6 5.53 5 101 Psc 01:35:46.4 +14:39:41 5.9 2.89 7 PPM 117698 01:48:54.5 +16:22:38 7.5 0.91 4 PPM 117644 01:45:30.9 +16:15:58 9.8 0.79 4 PPM 117656 01:46:25.6 +15:42:47 10.1 0.22 4 18493_Demoleon 01:47:08.1 +15:34:29 16.6 4 Positions are for J2000