Occultation event with (5436) Eumelos, event index number 992
Regions able to see the event: Europe
Geocentric closest approach at 2025/05/21 20:15:05 UTC
J2000 position of star is 09:21:23.3 +07:56:25
Equinox of date position of star is 09:22:44.3 +07:49:52
Star is 151 degrees from the moon. Moon is 35% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.60 seconds with the standard RECON-QHY system.
SNR of 4.8 per integration for unocculted signal
Expected flux drop is 58% with SNR of 2.8 for the occulted depth (per occulted point)
Apparent velocity is 19.0 km/sec on the sky relative to the star, or, 19.0 arcsec/hr.
Position angle of asteroid motion is 358.0 degrees
The recommended exposure time corresponds to 11.4 km per image.
The 1-sigma error in the time of the event is 2.5 seconds.
The 1-sigma cross-track error in the shadow position is 18.0 km.
The sky-plane scale is 3583.6 km/arcsec.
Diameter estimates:
48.5 km assuming a 5% albedo, aximum of 2.6 sec for a central chord
19.8 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 48.5 km used for deployment plan.
Star training set for 5436_Eumelos, (2025/05/21 20:15UT) Object RA Dec mag sep mel Regulus 10:09:43.3 +11:50:32 1.3 12.25 162 2Ome Leo 09:29:48.9 +08:56:42 6.0 2.07 153 PPM 155700 09:21:20.1 +08:04:24 7.9 0.42 151 PPM 155737 09:23:03.0 +08:06:10 8.6 0.28 151 5436_Eumelos 09:22:44.3 +07:49:52 15.9 151 Positions are for equinox of date
Star training set for 5436_Eumelos, (2025/05/21 20:15UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 12.25 162 2Ome Leo 09:28:27.5 +09:03:24 6.0 2.07 153 PPM 155700 09:19:58.9 +08:10:55 7.9 0.42 151 PPM 155737 09:21:41.9 +08:12:43 8.6 0.28 151 5436_Eumelos 09:21:23.3 +07:56:25 15.9 151 Positions are for J2000