Occultation event with (5284) Orsilocus, event index number 1440
Regions able to see the event: Europe
Geocentric closest approach at 2025/11/01 04:28:12 UTC
J2000 position of star is 12:10:38.0 +16:40:26
Equinox of date position of star is 12:11:57.0 +16:31:49
Star is 158 degrees from the moon. Moon is 75% illuminated.
Stellar brightness G=16.2, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.70 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 42% with SNR of 1.3 for the occulted depth (per occulted point)
Apparent velocity is 35.3 km/sec on the sky relative to the star, or, 30.3 arcsec/hr.
Position angle of asteroid motion is 102.5 degrees
The recommended exposure time corresponds to 24.7 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 29.9 km.
The sky-plane scale is 4189.1 km/arcsec.
Diameter estimates:
57.0 km assuming a 5% albedo, aximum of 1.6 sec for a central chord
23.3 km assuming a 30% albedo, maximum of 0.7 sec for a central chord
Cross-track diameter of 50.2 km used for deployment plan.
Star training set for 5284_Orsilocus, (2025/11/01 04:28UT) Object RA Dec mag sep mel Arcturus 14:16:50.5 +19:02:57 0.0 29.80 128 Denebola 11:50:22.6 +14:25:39 2.1 5.61 163 3 Com 12:11:50.5 +16:39:56 6.4 0.14 158 5284_Orsilocus 12:11:57.0 +16:31:49 15.9 157 Positions are for equinox of date
Star training set for 5284_Orsilocus, (2025/11/01 04:28UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 29.80 128 Denebola 11:49:02.7 +14:34:16 2.1 5.61 163 3 Com 12:10:31.6 +16:48:33 6.4 0.14 158 5284_Orsilocus 12:10:38.0 +16:40:26 15.9 158 Positions are for J2000