Occultation event with (1404) Ajax, event index number 3817
Regions able to see the event: SAmericaS
Geocentric closest approach at 2026/06/30 22:43:00 UTC
J2000 position of star is 10:51:01.6 +00:45:50
Equinox of date position of star is 10:52:23.2 +00:37:22
Star is 125 degrees from the moon. Moon is 99% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=15.4
Use an exposure time of 1.25 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 25% with SNR of 0.8 for the occulted depth (per occulted point)
Apparent velocity is 23.7 km/sec on the sky relative to the star, or, 19.4 arcsec/hr.
Position angle of asteroid motion is 114.5 degrees
The recommended exposure time corresponds to 29.6 km per image.
The 1-sigma error in the time of the event is 1.4 seconds.
The 1-sigma cross-track error in the shadow position is 14.6 km.
The sky-plane scale is 4391.9 km/arcsec.
Diameter estimates:
83.2 km assuming a 5% albedo, maximum of 3.5 sec for a central chord
34.0 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 84.0 km used for deployment plan.
Star training set for 1404_Ajax, (2026/06/30 22:43UT) Object RA Dec mag sep mel Regulus 10:09:46.8 +11:50:12 1.3 15.41 140 55 Leo 10:57:04.1 +00:35:42 6.2 1.17 124 PPM 157264 10:52:30.9 +00:38:42 8.2 0.04 125 1404_Ajax 10:52:23.2 +00:37:22 15.4 125 Positions are for equinox of date
Star training set for 1404_Ajax, (2026/06/30 22:43UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 15.41 140 55 Leo 10:55:42.5 +00:44:13 6.2 1.17 124 PPM 157264 10:51:09.2 +00:47:10 8.2 0.04 125 1404_Ajax 10:51:01.6 +00:45:50 15.4 125 Positions are for J2000