Occultation event with (5638) Deikoon, event index number 1396
Regions able to see the event: UAE
Geocentric closest approach at 2025/10/21 18:12:10 UTC
J2000 position of star is 01:41:50.5 -00:07:28
Equinox of date position of star is 01:43:09.8 +00:00:18
Star is 164 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=11.3, apparent brightess of occulting body is G=15.7
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 31.3 per integration for unocculted signal
Expected flux drop is 98% with SNR of 30.7 for the occulted depth (per occulted point)
Apparent velocity is 17.8 km/sec on the sky relative to the star, or, 19.1 arcsec/hr.
Position angle of asteroid motion is 65.3 degrees
The recommended exposure time corresponds to 2.1 km per image.
The 1-sigma error in the time of the event is 1.0 seconds.
The 1-sigma cross-track error in the shadow position is 23.2 km.
The sky-plane scale is 3351.5 km/arcsec.
Diameter estimates:
46.3 km assuming a 5% albedo, aximum of 2.6 sec for a central chord
18.9 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 41.5 km used for deployment plan.
Star training set for 5638_Deikoon, (2025/10/21 18:12UT) Object RA Dec mag sep mel Fomalhaut 22:59:04.2 -29:29:06 1.2 48.95 119 68Omi Cet 02:20:39.1 -02:51:42 2.0 9.80 161 PPM 183660 01:39:10.6 -03:18:37 6.5 3.46 161 PPM 174960 01:42:41.4 -00:22:37 8.5 0.40 164 PPM 174963 01:43:20.2 -00:21:10 9.1 0.36 164 PPM 174961 01:43:07.8 -00:01:42 10.4 0.03 164 5638_Deikoon 01:43:09.8 +00:00:18 15.7 165 Positions are for equinox of date
Star training set for 5638_Deikoon, (2025/10/21 18:12UT) Object RA Dec mag sep mel Fomalhaut 22:57:39.7 -29:37:24 1.2 48.95 119 68Omi Cet 02:19:20.8 -02:58:46 2.0 9.80 161 PPM 183660 01:37:52.1 -03:26:27 6.5 3.46 161 PPM 174960 01:41:22.2 -00:30:24 8.5 0.40 164 PPM 174963 01:42:00.9 -00:28:56 9.1 0.36 164 PPM 174961 01:41:48.4 -00:09:29 10.4 0.03 164 5638_Deikoon 01:41:50.5 -00:07:28 15.7 164 Positions are for J2000