Occultation event with (4827) Dares, event index number 1381
Regions able to see the event: Australia
Geocentric closest approach at 2025/10/17 13:49:20 UTC
J2000 position of star is 03:16:21.9 +20:44:01
Equinox of date position of star is 03:17:51.1 +20:49:39
Star is 108 degrees from the moon. Moon is 14% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=15.3
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 28% with SNR of 0.9 for the occulted depth (per occulted point)
Apparent velocity is 13.1 km/sec on the sky relative to the star, or, 16.2 arcsec/hr.
Position angle of asteroid motion is 69.5 degrees
The recommended exposure time corresponds to 11.8 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 25.7 km.
The sky-plane scale is 2903.5 km/arcsec.
Diameter estimates:
46.3 km assuming a 5% albedo, aximum of 3.5 sec for a central chord
18.9 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 42.8 km used for deployment plan.
Star training set for 4827_Dares, (2025/10/17 13:49UT) Object RA Dec mag sep mel Aldebaran 04:37:24.2 +16:33:32 0.8 19.30 91 44Zet Per 03:55:45.6 +31:57:29 2.8 13.98 97 58Zet Ari 03:16:23.4 +21:08:18 4.9 0.46 108 PPM 092331 03:17:22.5 +20:47:46 8.2 0.12 108 4827_Dares 03:17:51.1 +20:49:39 15.3 108 Positions are for equinox of date
Star training set for 4827_Dares, (2025/10/17 13:49UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 19.30 91 44Zet Per 03:54:07.9 +31:53:01 2.8 13.98 97 58Zet Ari 03:14:54.0 +21:02:38 4.9 0.46 108 PPM 092331 03:15:53.3 +20:42:08 8.2 0.12 108 4827_Dares 03:16:21.9 +20:44:01 15.3 108 Positions are for J2000