Occultation event with (38050) Bias, event index number 1089
Regions able to see the event: Australia
Geocentric closest approach at 2025/06/23 09:39:43 UTC
J2000 position of star is 08:51:49.7 -08:51:43
Equinox of date position of star is 08:53:04.1 -08:57:32
Star is 78 degrees from the moon. Moon is 6% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=15.6
Use an exposure time of 0.55 seconds with the standard RECON-QHY system.
SNR of 3.2 per integration for unocculted signal
Expected flux drop is 42% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 34.5 km/sec on the sky relative to the star, or, 30.3 arcsec/hr.
Position angle of asteroid motion is 353.9 degrees
The recommended exposure time corresponds to 19.0 km per image.
The 1-sigma error in the time of the event is 1.1 seconds.
The 1-sigma cross-track error in the shadow position is 14.4 km.
The sky-plane scale is 4106.6 km/arcsec.
Diameter estimates:
63.4 km assuming a 5% albedo, aximum of 1.8 sec for a central chord
25.9 km assuming a 30% albedo, maximum of 0.7 sec for a central chord
Cross-track diameter of 63.4 km used for deployment plan.
Star training set for 38050_Bias, (2025/06/23 09:40UT) Object RA Dec mag sep mel Regulus 10:09:43.6 +11:50:30 1.3 28.21 86 Alphard 09:28:50.4 -08:46:13 2.0 8.84 86 17 Hya 08:56:44.5 -08:04:10 6.3 1.27 78 PPM 191784 08:52:57.8 -09:13:21 8.4 0.27 78 PPM 191782 08:52:53.6 -09:03:41 9.0 0.11 78 38050_Bias 08:53:04.1 -08:57:32 15.6 78 Positions are for equinox of date
Star training set for 38050_Bias, (2025/06/23 09:40UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 28.21 86 Alphard 09:27:35.2 -08:39:30 2.0 8.84 86 17 Hya 08:55:29.6 -07:58:15 6.3 1.27 78 PPM 191784 08:51:43.5 -09:07:33 8.4 0.27 78 PPM 191782 08:51:39.2 -08:57:53 9.0 0.11 78 38050_Bias 08:51:49.7 -08:51:43 15.6 78 Positions are for J2000