Occultation event with (4708) Polydoros, event index number 1274
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/09/09 00:15:15 UTC
J2000 position of star is 00:49:37.7 +14:35:06
Equinox of date position of star is 00:50:58.7 +14:43:29
Star is 15 degrees from the moon. Moon is 98% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=14.9
Use an exposure time of 1.45 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 16% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 12.0 km/sec on the sky relative to the star, or, 14.7 arcsec/hr.
Position angle of asteroid motion is 76.4 degrees
The recommended exposure time corresponds to 17.4 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 26.4 km.
The sky-plane scale is 2933.4 km/arcsec.
Diameter estimates:
58.6 km assuming a 5% albedo, aximum of 4.9 sec for a central chord
23.9 km assuming a 30% albedo, maximum of 2.0 sec for a central chord
Cross-track diameter of 55.0 km used for deployment plan.
Star training set for 4708_Polydoros, (2025/09/09 00:15UT) Object RA Dec mag sep mel Algenib 00:14:33.7 +15:19:34 2.8 8.81 13 64 Psc 00:50:20.0 +17:04:44 5.1 2.36 17 PPM 116794 00:50:25.6 +14:56:56 8.2 0.26 16 PPM 116802 00:51:03.3 +14:36:15 9.6 0.12 15 4708_Polydoros 00:50:58.7 +14:43:29 14.9 16 Positions are for equinox of date
Star training set for 4708_Polydoros, (2025/09/09 00:15UT) Object RA Dec mag sep mel Algenib 00:13:14.2 +15:11:00 2.8 8.81 13 64 Psc 00:48:58.7 +16:56:21 5.1 2.36 17 PPM 116794 00:49:04.7 +14:48:33 8.2 0.26 16 PPM 116802 00:49:42.4 +14:27:52 9.6 0.12 15 4708_Polydoros 00:49:37.7 +14:35:06 14.9 15 Positions are for J2000