Occultation event with (23958) 98VD30, event index number 3857
Regions able to see the event: NZ
Geocentric closest approach at 2026/07/18 06:10:48 UTC
J2000 position of star is 11:40:41.2 -12:49:25
Equinox of date position of star is 11:42:02.1 -12:58:15
Star is 18 degrees from the moon. Moon is 19% illuminated.
Stellar brightness G=13.2, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 9.5 per integration for unocculted signal
Expected flux drop is 92% with SNR of 8.8 for the occulted depth (per occulted point)
Apparent velocity is 26.9 km/sec on the sky relative to the star, or, 24.4 arcsec/hr.
Position angle of asteroid motion is 91.5 degrees
The recommended exposure time corresponds to 3.2 km per image.
The 1-sigma error in the time of the event is 0.2 seconds.
The 1-sigma cross-track error in the shadow position is 41.0 km.
The sky-plane scale is 3973.3 km/arcsec.
Diameter estimates:
55.5 km assuming a 5% albedo, maximum of 2.1 sec for a central chord
22.6 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 46.0 km used for deployment plan.
Star training set for 23958_98VD30, (2026/07/18 06:11UT) Object RA Dec mag sep mel Spica 13:26:35.7 -11:17:56 1.0 25.60 37 4Gam Crv 12:17:10.5 -17:41:21 2.6 9.69 27 24Iot Crt 11:40:01.0 -13:20:54 5.6 0.62 18 PPM 224723 11:40:51.3 -13:19:57 6.7 0.46 18 PPM 224746 11:41:47.9 -12:46:51 9.4 0.20 18 23958_98VD30 11:42:02.1 -12:58:15 15.9 18 Positions are for equinox of date
Star training set for 23958_98VD30, (2026/07/18 06:11UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 25.60 37 4Gam Crv 12:15:48.1 -17:32:30 2.6 9.69 27 24Iot Crt 11:38:40.2 -13:12:04 5.6 0.62 18 PPM 224723 11:39:30.3 -13:11:07 6.7 0.46 18 PPM 224746 11:40:27.0 -12:38:01 9.4 0.20 18 23958_98VD30 11:40:41.2 -12:49:25 15.9 18 Positions are for J2000