Occultation event with (4708) Polydoros, event index number 3859
Regions able to see the event: SMexico
Geocentric closest approach at 2026/07/18 11:27:11 UTC
J2000 position of star is 03:07:55.0 +23:31:07
Equinox of date position of star is 03:09:28.0 +23:37:09
Star is 119 degrees from the moon. Moon is 21% illuminated.
Stellar brightness G=15.3, apparent brightess of occulting body is G=15.6
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 5.2 per integration for unocculted signal
Expected flux drop is 58% with SNR of 3.0 for the occulted depth (per occulted point)
Apparent velocity is 26.1 km/sec on the sky relative to the star, or, 24.5 arcsec/hr.
Position angle of asteroid motion is 70.7 degrees
The recommended exposure time corresponds to 13.0 km per image.
The 1-sigma error in the time of the event is 0.7 seconds.
The 1-sigma cross-track error in the shadow position is 29.5 km.
The sky-plane scale is 3827.3 km/arcsec.
Diameter estimates:
58.6 km assuming a 5% albedo, maximum of 2.2 sec for a central chord
23.9 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 55.0 km used for deployment plan.
Star training set for 4708_Polydoros, (2026/07/18 11:27UT) Object RA Dec mag sep mel Aldebaran 04:37:26.8 +16:33:38 0.8 21.80 100 44Zet Per 03:55:48.4 +31:57:37 2.8 13.20 107 52 Ari 03:07:00.5 +25:21:25 6.1 1.83 119 PPM 092225 03:09:25.3 +23:47:17 8.1 0.17 119 4708_Polydoros 03:09:28.0 +23:37:09 15.6 119 Positions are for equinox of date
Star training set for 4708_Polydoros, (2026/07/18 11:27UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 21.80 100 44Zet Per 03:54:07.9 +31:53:01 2.8 13.20 107 52 Ari 03:05:26.7 +25:15:19 6.1 1.83 119 PPM 092225 03:07:52.3 +23:41:16 8.1 0.17 119 4708_Polydoros 03:07:55.0 +23:31:07 15.6 119 Positions are for J2000