Occultation event with (38050) Bias, event index number 978
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/05/17 00:07:09 UTC
J2000 position of star is 08:25:04.7 -09:23:10
Equinox of date position of star is 08:26:18.2 -09:28:12
Star is 138 degrees from the moon. Moon is 83% illuminated.
Stellar brightness G=14.2, apparent brightess of occulting body is G=15.5
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 77% with SNR of 7.7 for the occulted depth (per occulted point)
Apparent velocity is 23.6 km/sec on the sky relative to the star, or, 22.5 arcsec/hr.
Position angle of asteroid motion is 15.4 degrees
The recommended exposure time corresponds to 8.3 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 16.2 km.
The sky-plane scale is 3772.0 km/arcsec.
Diameter estimates:
63.4 km assuming a 5% albedo, aximum of 2.7 sec for a central chord
25.9 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 63.4 km used for deployment plan.
Star training set for 38050_Bias, (2025/05/17 00:07UT) Object RA Dec mag sep mel Sirius 06:46:15.9 -16:45:09 -1.5 25.39 136 Alphard 09:28:50.1 -08:46:11 2.0 15.45 130 PPM 191380 08:29:33.6 -08:54:07 6.5 0.98 139 PPM 191315 08:26:22.5 -09:52:09 8.2 0.40 138 PPM 191314 08:26:13.4 -09:26:31 9.2 0.03 138 38050_Bias 08:26:18.2 -09:28:12 15.5 138 Positions are for equinox of date
Star training set for 38050_Bias, (2025/05/17 00:07UT) Object RA Dec mag sep mel Sirius 06:45:07.9 -16:43:28 -1.5 25.39 136 Alphard 09:27:35.2 -08:39:30 2.0 15.45 130 PPM 191380 08:28:19.8 -08:49:00 6.5 0.98 139 PPM 191315 08:25:09.2 -09:47:07 8.2 0.40 138 PPM 191314 08:24:59.9 -09:21:29 9.2 0.03 138 38050_Bias 08:25:04.7 -09:23:10 15.5 138 Positions are for J2000