Occultation event with (19725) 99WT4, event index number 730
Regions able to see the event: Europe
Geocentric closest approach at 2025/02/27 21:46:40 UTC
J2000 position of star is 08:39:23.1 +30:51:40
Equinox of date position of star is 08:40:55.8 +30:46:16
Star is 145 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=15.7
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
Expected flux drop is 46% with SNR of 6.2 per integration
Apparent velocity is 11.5 km/sec on the sky relative to the star, or, 14.1 arcsec/hr.
The recommended exposure time corresponds to 9.8 km per image.
The 1-sigma error in the time of the event is 4.2 seconds.
The 1-sigma cross-track error in the shadow position is 11.3 km.
The sky-plane scale is 2934.6 km/arcsec.
Diameter estimates:
40.5 km assuming a 5% albedo, aximum of 3.5 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 40.5 km used for deployment plan.
Star training set for 19725_99WT4, (2025/02/27 21:47UT) Object RA Dec mag sep mel Pollux 07:46:51.1 +27:57:48 1.1 12.10 135 PPM 073899 08:41:51.6 +31:51:04 6.5 1.10 145 PPM 073869 08:40:10.8 +30:37:20 8.6 0.22 145 PPM 073893 08:41:15.2 +30:37:36 10.1 0.16 145 19725_99WT4 08:40:55.8 +30:46:16 15.7 145 Positions are for equinox of date
Star training set for 19725_99WT4, (2025/02/27 21:47UT) Object RA Dec mag sep mel Pollux 07:45:17.8 +28:01:33 1.1 12.10 135 PPM 073899 08:40:18.2 +31:56:30 6.5 1.10 145 PPM 073869 08:38:38.1 +30:42:44 8.6 0.22 145 PPM 073893 08:39:42.5 +30:43:01 10.1 0.16 145 19725_99WT4 08:39:23.1 +30:51:40 15.7 145 Positions are for J2000