Occultation event with (15440) Eioneus, event index number 3177
Regions able to see the event: UAE
Geocentric closest approach at 2026/01/27 18:10:34 UTC
J2000 position of star is 11:10:59.3 +26:17:46
Equinox of date position of star is 11:12:23.0 +26:09:15
Star is 98 degrees from the moon. Moon is 68% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=14.8
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 7.9 per integration for unocculted signal
Expected flux drop is 41% with SNR of 3.3 for the occulted depth (per occulted point)
Apparent velocity is 17.3 km/sec on the sky relative to the star, or, 19.1 arcsec/hr.
Position angle of asteroid motion is 149.7 degrees
The recommended exposure time corresponds to 15.6 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 19.9 km.
The sky-plane scale is 3260.2 km/arcsec.
Diameter estimates:
72.4 km assuming a 5% albedo, maximum of 4.2 sec for a central chord
29.6 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 62.5 km used for deployment plan.
Star training set for 15440_Eioneus, (2026/01/27 18:11UT) Object RA Dec mag sep mel Regulus 10:09:45.5 +11:50:20 1.3 20.55 91 68Del Leo 11:15:29.5 +20:22:50 2.6 5.82 101 67 Leo 11:10:12.7 +24:31:01 5.7 1.71 98 PPM 100966 11:13:05.8 +26:41:25 8.3 0.56 97 PPM 100957 11:12:19.9 +26:07:34 9.8 0.03 98 15440_Eioneus 11:12:23.0 +26:09:15 14.8 98 Positions are for equinox of date
Star training set for 15440_Eioneus, (2026/01/27 18:11UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 20.55 91 68Del Leo 11:14:06.8 +20:31:22 2.6 5.82 101 67 Leo 11:08:49.1 +24:39:31 5.7 1.71 98 PPM 100966 11:11:42.0 +26:49:56 8.3 0.56 97 PPM 100957 11:10:56.2 +26:16:05 9.8 0.03 98 15440_Eioneus 11:10:59.3 +26:17:46 14.8 98 Positions are for J2000