Occultation event with (18493) Demoleon, event index number 1136
Regions able to see the event: SAmericaS
Geocentric closest approach at 2025/07/13 10:19:23 UTC
J2000 position of star is 01:59:40.4 +16:24:25
Equinox of date position of star is 02:01:03.9 +16:31:48
Star is 71 degrees from the moon. Moon is 93% illuminated.
Stellar brightness G=14.5, apparent brightess of occulting body is G=16.5
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 9.4 per integration for unocculted signal
Expected flux drop is 86% with SNR of 8.1 for the occulted depth (per occulted point)
Apparent velocity is 18.7 km/sec on the sky relative to the star, or, 17.7 arcsec/hr.
The recommended exposure time corresponds to 8.4 km per image.
The 1-sigma error in the time of the event is 2.9 seconds.
The 1-sigma cross-track error in the shadow position is 7.1 km.
The sky-plane scale is 3802.9 km/arcsec.
Diameter estimates:
40.5 km assuming a 5% albedo, aximum of 2.2 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 40.5 km used for deployment plan.
Star training set for 18493_Demoleon, (2025/07/13 10:19UT) Object RA Dec mag sep mel Aldebaran 04:37:23.3 +16:33:31 0.8 37.40 107 6Bet Ari 01:56:03.4 +20:55:54 2.6 4.56 72 19 Ari 02:14:27.1 +15:23:54 5.7 3.41 74 PPM 117871 02:02:33.4 +16:41:15 7.8 0.39 72 PPM 117860 02:01:30.5 +16:34:46 9.8 0.12 71 18493_Demoleon 02:01:03.9 +16:31:48 16.5 72 Positions are for equinox of date
Star training set for 18493_Demoleon, (2025/07/13 10:19UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 37.40 107 6Bet Ari 01:54:38.6 +20:48:26 2.6 4.56 72 19 Ari 02:13:03.5 +15:16:47 5.7 3.41 74 PPM 117871 02:01:09.7 +16:33:54 7.8 0.39 72 PPM 117860 02:00:06.9 +16:27:24 9.8 0.12 71 18493_Demoleon 01:59:40.4 +16:24:25 16.5 71 Positions are for J2000