Occultation event with (5284) Orsilocus, event index number 1679
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/12/14 07:33:55 UTC
J2000 position of star is 12:40:56.4 +15:55:07
Equinox of date position of star is 12:42:14.4 +15:46:36
Star is 27 degrees from the moon. Moon is 27% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=15.8
Use an exposure time of 0.60 seconds with the standard RECON-QHY system.
SNR of 4.9 per integration for unocculted signal
Expected flux drop is 55% with SNR of 2.7 for the occulted depth (per occulted point)
Apparent velocity is 20.9 km/sec on the sky relative to the star, or, 19.8 arcsec/hr.
Position angle of asteroid motion is 84.7 degrees
The recommended exposure time corresponds to 12.5 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 34.5 km.
The sky-plane scale is 3798.2 km/arcsec.
Diameter estimates:
57.0 km assuming a 5% albedo, aximum of 2.7 sec for a central chord
23.3 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 50.2 km used for deployment plan.
Star training set for 5284_Orsilocus, (2025/12/14 07:34UT) Object RA Dec mag sep mel Arcturus 14:16:50.8 +19:02:55 0.0 22.79 34 Vindemiatrix 13:03:28.1 +10:49:13 2.8 7.16 22 29 Com 12:50:12.2 +13:58:53 5.6 2.63 25 PPM 129240 12:41:47.1 +16:08:14 8.2 0.38 28 5284_Orsilocus 12:42:14.4 +15:46:36 15.8 27 Positions are for equinox of date
Star training set for 5284_Orsilocus, (2025/12/14 07:34UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 22.79 34 Vindemiatrix 13:02:10.1 +10:57:33 2.8 7.16 22 29 Com 12:48:54.3 +14:07:21 5.6 2.63 25 PPM 129240 12:40:29.1 +16:16:45 8.2 0.38 28 5284_Orsilocus 12:40:56.4 +15:55:07 15.8 27 Positions are for J2000