Occultation event with (48438) 89WJ2, event index number 4039
Regions able to see the event: SAfrica
Geocentric closest approach at 2026/08/18 04:07:39 UTC
J2000 position of star is 06:24:56.5 +18:39:01
Equinox of date position of star is 06:26:30.3 +18:38:02
Star is 117 degrees from the moon. Moon is 31% illuminated.
Stellar brightness G=15.8, apparent brightess of occulting body is G=16.6
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 66% with SNR of 2.1 for the occulted depth (per occulted point)
Apparent velocity is 30.7 km/sec on the sky relative to the star, or, 26.8 arcsec/hr.
Position angle of asteroid motion is 82.8 degrees
The recommended exposure time corresponds to 13.8 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 27.6 km.
The sky-plane scale is 4116.2 km/arcsec.
Diameter estimates:
40.2 km assuming a 5% albedo, maximum of 1.3 sec for a central chord
16.4 km assuming a 30% albedo, maximum of 0.5 sec for a central chord
Cross-track diameter of 36.1 km used for deployment plan.
Star training set for 48438_89WJ2, (2026/08/18 04:08UT) Object RA Dec mag sep mel Betelgeuse 05:56:36.9 +07:24:35 0.4 13.37 121 Alhena 06:39:15.0 +16:22:27 1.9 3.79 113 18Nu Gem 06:30:32.6 +20:11:34 4.1 1.83 116 PPM 122473 06:27:43.9 +18:44:18 7.9 0.31 116 PPM 122425 06:26:26.5 +18:36:11 9.8 0.03 117 48438_89WJ2 06:26:30.3 +18:38:02 16.6 116 Positions are for equinox of date
Star training set for 48438_89WJ2, (2026/08/18 04:08UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 13.37 121 Alhena 06:37:42.8 +16:23:56 1.9 3.79 113 18Nu Gem 06:28:57.8 +20:12:43 4.1 1.83 116 PPM 122473 06:26:10.0 +18:45:21 7.9 0.31 116 PPM 122425 06:24:52.7 +18:37:10 9.8 0.03 117 48438_89WJ2 06:24:56.5 +18:39:01 16.6 117 Positions are for J2000