Occultation event with (5130) Ilioneus, event index number 3171
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/01/26 01:16:31 UTC
J2000 position of star is 00:28:06.7 +13:39:37
Equinox of date position of star is 00:29:27.9 +13:48:15
Star is 23 degrees from the moon. Moon is 48% illuminated.
Stellar brightness G=13.8, apparent brightess of occulting body is G=15.5
Use an exposure time of 0.20 seconds with the standard RECON-QHY system.
SNR of 8.6 per integration for unocculted signal
Expected flux drop is 82% with SNR of 7.1 for the occulted depth (per occulted point)
Apparent velocity is 25.8 km/sec on the sky relative to the star, or, 23.6 arcsec/hr.
Position angle of asteroid motion is 82.2 degrees
The recommended exposure time corresponds to 5.2 km per image.
The 1-sigma error in the time of the event is 0.3 seconds.
The 1-sigma cross-track error in the shadow position is 22.2 km.
The sky-plane scale is 3950.7 km/arcsec.
Diameter estimates:
65.8 km assuming a 5% albedo, maximum of 2.5 sec for a central chord
26.9 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 60.7 km used for deployment plan.
Star training set for 5130_Ilioneus, (2026/01/26 01:17UT) Object RA Dec mag sep mel Algenib 00:14:34.9 +15:19:42 2.8 3.91 26 42 Psc 00:23:46.6 +13:37:37 6.2 1.39 24 PPM 116542 00:33:02.6 +13:03:21 7.9 1.15 22 PPM 116472 00:29:06.6 +13:50:54 9.1 0.10 23 5130_Ilioneus 00:29:27.9 +13:48:15 15.5 22 Positions are for equinox of date
Star training set for 5130_Ilioneus, (2026/01/26 01:17UT) Object RA Dec mag sep mel Algenib 00:13:14.2 +15:11:00 2.8 3.91 26 42 Psc 00:22:25.6 +13:28:57 6.2 1.39 24 PPM 116542 00:31:41.3 +12:54:44 7.9 1.15 22 PPM 116472 00:27:45.3 +13:42:16 9.1 0.10 23 5130_Ilioneus 00:28:06.7 +13:39:37 15.5 23 Positions are for J2000