Occultation event with (15440) Eioneus, event index number 3573
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/04/04 01:25:51 UTC
J2000 position of star is 10:41:29.8 +31:20:32
Equinox of date position of star is 10:42:57.6 +31:12:16
Star is 70 degrees from the moon. Moon is 96% illuminated.
Stellar brightness G=15.8, apparent brightess of occulting body is G=14.9
Use an exposure time of 1.50 seconds with the standard RECON-QHY system.
SNR of 6.3 per integration for unocculted signal
Expected flux drop is 31% with SNR of 1.9 for the occulted depth (per occulted point)
Apparent velocity is 10.3 km/sec on the sky relative to the star, or, 11.1 arcsec/hr.
Position angle of asteroid motion is 103.0 degrees
The recommended exposure time corresponds to 15.5 km per image.
The 1-sigma error in the time of the event is 0.7 seconds.
The 1-sigma cross-track error in the shadow position is 40.5 km.
The sky-plane scale is 3347.2 km/arcsec.
Diameter estimates:
72.4 km assuming a 5% albedo, maximum of 7.0 sec for a central chord
29.6 km assuming a 30% albedo, maximum of 2.9 sec for a central chord
Cross-track diameter of 62.5 km used for deployment plan.
Star training set for 15440_Eioneus, (2026/04/04 01:26UT) Object RA Dec mag sep mel Regulus 10:09:46.1 +11:50:16 1.3 20.83 67 68Del Leo 11:15:30.1 +20:22:46 2.6 13.06 58 33 LMi 10:33:20.4 +32:14:38 5.8 2.29 73 PPM 075409 10:43:39.2 +31:33:32 7.8 0.38 71 PPM 075414 10:43:55.2 +30:53:31 10.9 0.37 70 15440_Eioneus 10:42:57.6 +31:12:16 14.9 70 Positions are for equinox of date
Star training set for 15440_Eioneus, (2026/04/04 01:26UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 20.83 67 68Del Leo 11:14:06.8 +20:31:22 2.6 13.06 58 33 LMi 10:31:51.4 +32:22:47 5.8 2.29 73 PPM 075409 10:42:11.3 +31:41:49 7.8 0.38 71 PPM 075414 10:42:27.5 +31:01:48 10.9 0.37 70 15440_Eioneus 10:41:29.8 +31:20:32 14.9 70 Positions are for J2000