Occultation event with (9431) Pytho, event index number 1004
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/05/26 23:10:45 UTC
J2000 position of star is 09:29:45.3 -01:16:10
Equinox of date position of star is 09:31:03.0 -01:22:54
Star is 83 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=16.5
Use an exposure time of 0.80 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 52% with SNR of 1.6 for the occulted depth (per occulted point)
Apparent velocity is 20.0 km/sec on the sky relative to the star, or, 18.3 arcsec/hr.
Position angle of asteroid motion is 12.1 degrees
The recommended exposure time corresponds to 16.0 km per image.
The 1-sigma error in the time of the event is 2.5 seconds.
The 1-sigma cross-track error in the shadow position is 12.3 km.
The sky-plane scale is 3942.3 km/arcsec.
Diameter estimates:
44.7 km assuming a 5% albedo, aximum of 2.2 sec for a central chord
18.2 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 44.7 km used for deployment plan.
Star training set for 9431_Pytho, (2025/05/26 23:11UT) Object RA Dec mag sep mel Regulus 10:09:43.3 +11:50:31 1.3 16.34 86 Alphard 09:28:50.1 -08:46:12 2.0 7.41 86 32Tau2Hya 09:33:16.5 -01:17:54 4.2 0.56 84 PPM 177878 09:30:19.8 -01:22:10 6.8 0.18 83 PPM 177888 09:31:23.4 -01:30:20 9.9 0.15 83 9431_Pytho 09:31:03.0 -01:22:54 16.5 83 Positions are for equinox of date
Star training set for 9431_Pytho, (2025/05/26 23:11UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 16.34 86 Alphard 09:27:35.2 -08:39:30 2.0 7.41 86 32Tau2Hya 09:31:58.9 -01:11:06 4.2 0.56 84 PPM 177878 09:29:02.1 -01:15:26 6.8 0.18 83 PPM 177888 09:30:05.8 -01:23:35 9.9 0.15 83 9431_Pytho 09:29:45.3 -01:16:10 16.5 83 Positions are for J2000