Occultation event with (18493) Demoleon, event index number 5058
Regions able to see the event: Europe
Geocentric closest approach at 2026/12/05 20:56:11 UTC
J2000 position of star is 03:56:37.7 +10:43:52
Equinox of date position of star is 03:58:06.4 +10:48:28
Star is 155 degrees from the moon. Moon is 9% illuminated.
Stellar brightness G=15.1, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 5.9 per integration for unocculted signal
Expected flux drop is 69% with SNR of 4.1 for the occulted depth (per occulted point)
Apparent velocity is 17.4 km/sec on the sky relative to the star, or, 19.1 arcsec/hr.
Position angle of asteroid motion is 71.1 degrees
The recommended exposure time corresponds to 7.8 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 34.0 km.
The sky-plane scale is 3270.9 km/arcsec.
Diameter estimates:
40.5 km assuming a 5% albedo, maximum of 2.3 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 33.5 km used for deployment plan.
Star training set for 18493_Demoleon, (2026/12/05 20:56UT) Object RA Dec mag sep mel Aldebaran 04:37:28.1 +16:33:40 0.8 11.15 147 Menkar 03:03:41.4 +04:11:38 2.5 15.01 162 PPM 119523 04:01:09.3 +10:24:19 6.5 0.85 154 PPM 119506 04:00:06.2 +11:06:10 8.5 0.57 154 PPM 119483 03:58:37.6 +10:57:43 9.7 0.20 155 18493_Demoleon 03:58:06.4 +10:48:28 15.9 154 Positions are for equinox of date
Star training set for 18493_Demoleon, (2026/12/05 20:56UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 11.15 147 Menkar 03:02:16.8 +04:05:21 2.5 15.01 162 PPM 119523 03:59:40.7 +10:19:50 6.5 0.85 154 PPM 119506 03:58:37.4 +11:01:39 8.5 0.57 154 PPM 119483 03:57:08.8 +10:53:09 9.7 0.20 155 18493_Demoleon 03:56:37.7 +10:43:52 15.9 155 Positions are for J2000