Occultation event with (5436) Eumelos, event index number 1083
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/06/21 21:59:02 UTC
J2000 position of star is 09:40:57.3 +06:51:01
Equinox of date position of star is 09:42:17.9 +06:44:00
Star is 103 degrees from the moon. Moon is 17% illuminated.
Stellar brightness G=15.1, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 4.9 per integration for unocculted signal
Expected flux drop is 71% with SNR of 3.5 for the occulted depth (per occulted point)
Apparent velocity is 30.7 km/sec on the sky relative to the star, or, 28.3 arcsec/hr.
Position angle of asteroid motion is 345.8 degrees
The recommended exposure time corresponds to 10.7 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 22.9 km.
The sky-plane scale is 3904.6 km/arcsec.
Diameter estimates:
48.5 km assuming a 5% albedo, aximum of 1.6 sec for a central chord
19.8 km assuming a 30% albedo, maximum of 0.6 sec for a central chord
Cross-track diameter of 48.5 km used for deployment plan.
Star training set for 5436_Eumelos, (2025/06/21 21:59UT) Object RA Dec mag sep mel Regulus 10:09:43.6 +11:50:30 1.3 8.48 108 10 Leo 09:38:33.2 +06:43:13 6.1 0.93 102 PPM 156114 09:43:47.5 +07:16:38 8.3 0.66 103 PPM 156105 09:43:22.3 +06:36:52 8.6 0.29 104 5436_Eumelos 09:42:17.9 +06:44:00 16.0 104 Positions are for equinox of date
Star training set for 5436_Eumelos, (2025/06/21 21:59UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 8.48 108 10 Leo 09:37:12.5 +06:50:09 6.1 0.93 102 PPM 156114 09:42:26.7 +07:23:40 8.3 0.66 103 PPM 156105 09:42:01.8 +06:43:54 8.6 0.29 104 5436_Eumelos 09:40:57.3 +06:51:01 16.0 103 Positions are for J2000