Occultation event with (9431) Pytho, event index number 3532
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/03/28 22:25:01 UTC
J2000 position of star is 11:32:03.2 -08:17:21
Equinox of date position of star is 11:33:23.3 -08:26:04
Star is 40 degrees from the moon. Moon is 82% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=15.7
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 5.4 per integration for unocculted signal
Expected flux drop is 60% with SNR of 3.3 for the occulted depth (per occulted point)
Apparent velocity is 18.5 km/sec on the sky relative to the star, or, 20.3 arcsec/hr.
Position angle of asteroid motion is 129.3 degrees
The recommended exposure time corresponds to 9.2 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 26.9 km.
The sky-plane scale is 3274.9 km/arcsec.
Diameter estimates:
44.9 km assuming a 5% albedo, maximum of 2.4 sec for a central chord
18.3 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 38.4 km used for deployment plan.
Star training set for 9431_Pytho, (2026/03/28 22:25UT) Object RA Dec mag sep mel Spica 13:26:34.8 -11:17:51 1.0 28.01 66 4Gam Crv 12:17:09.6 -17:41:15 2.6 14.10 54 PPM 194572 11:34:07.7 -07:58:22 5.8 0.50 40 PPM 194570 11:34:04.7 -09:05:34 8.4 0.68 41 PPM 194549 11:32:48.3 -08:22:37 9.4 0.16 40 9431_Pytho 11:33:23.3 -08:26:04 15.7 41 Positions are for equinox of date
Star training set for 9431_Pytho, (2026/03/28 22:25UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 28.01 66 4Gam Crv 12:15:48.1 -17:32:30 2.6 14.10 54 PPM 194572 11:32:47.5 -07:49:39 5.8 0.50 40 PPM 194570 11:32:44.6 -08:56:52 8.4 0.68 41 PPM 194549 11:31:28.3 -08:13:55 9.4 0.16 40 9431_Pytho 11:32:03.2 -08:17:21 15.7 40 Positions are for J2000