Occultation event with (5130) Ilioneus, event index number 1290
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/09/16 19:30:14 UTC
J2000 position of star is 00:30:57.0 +19:58:14
Equinox of date position of star is 00:32:17.8 +20:06:44
Star is 98 degrees from the moon. Moon is 25% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=14.7
Use an exposure time of 1.05 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 18% with SNR of 0.6 for the occulted depth (per occulted point)
Apparent velocity is 14.8 km/sec on the sky relative to the star, or, 17.5 arcsec/hr.
Position angle of asteroid motion is 66.8 degrees
The recommended exposure time corresponds to 15.6 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 19.4 km.
The sky-plane scale is 3052.6 km/arcsec.
Diameter estimates:
65.8 km assuming a 5% albedo, aximum of 4.4 sec for a central chord
26.9 km assuming a 30% albedo, maximum of 1.8 sec for a central chord
Cross-track diameter of 60.7 km used for deployment plan.
Star training set for 5130_Ilioneus, (2025/09/16 19:30UT) Object RA Dec mag sep mel Deneb 20:42:18.6 +45:22:24 1.3 53.19 108 Algenib 00:14:33.8 +15:19:35 2.8 6.38 104 52 Psc 00:33:56.6 +20:26:08 5.4 0.50 97 PPM 116548 00:33:15.7 +19:47:05 8.2 0.40 98 5130_Ilioneus 00:32:17.8 +20:06:44 14.7 98 Positions are for equinox of date
Star training set for 5130_Ilioneus, (2025/09/16 19:30UT) Object RA Dec mag sep mel Deneb 20:41:25.9 +45:16:49 1.3 53.19 108 Algenib 00:13:14.2 +15:11:00 2.8 6.38 104 52 Psc 00:32:35.7 +20:17:38 5.4 0.50 97 PPM 116548 00:31:54.9 +19:38:35 8.2 0.40 98 5130_Ilioneus 00:30:57.0 +19:58:14 14.7 98 Positions are for J2000