Occultation event with (4827) Dares, event index number 1315
Regions able to see the event: Australia
Geocentric closest approach at 2025/09/27 14:37:27 UTC
J2000 position of star is 03:22:47.9 +21:18:10
Equinox of date position of star is 03:24:17.4 +21:23:36
Star is 165 degrees from the moon. Moon is 28% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=15.6
Use an exposure time of 1.65 seconds with the standard RECON-QHY system.
SNR of 6.8 per integration for unocculted signal
Expected flux drop is 42% with SNR of 2.9 for the occulted depth (per occulted point)
Apparent velocity is 6.3 km/sec on the sky relative to the star, or, 7.5 arcsec/hr.
Position angle of asteroid motion is 67.9 degrees
The recommended exposure time corresponds to 10.4 km per image.
The 1-sigma error in the time of the event is 2.3 seconds.
The 1-sigma cross-track error in the shadow position is 25.8 km.
The sky-plane scale is 3041.7 km/arcsec.
Diameter estimates:
46.3 km assuming a 5% albedo, aximum of 7.3 sec for a central chord
18.9 km assuming a 30% albedo, maximum of 3.0 sec for a central chord
Cross-track diameter of 42.8 km used for deployment plan.
Star training set for 4827_Dares, (2025/09/27 14:37UT) Object RA Dec mag sep mel Aldebaran 04:37:24.0 +16:33:32 0.8 17.93 169 44Zet Per 03:55:45.4 +31:57:28 2.8 12.68 172 61Tau1Ari 03:22:43.1 +21:14:17 5.3 0.40 165 PPM 092461 03:24:48.7 +21:03:37 8.0 0.35 165 PPM 092456 03:24:41.0 +21:39:31 9.4 0.28 165 4827_Dares 03:24:17.4 +21:23:36 15.6 166 Positions are for equinox of date
Star training set for 4827_Dares, (2025/09/27 14:37UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 17.93 169 44Zet Per 03:54:07.9 +31:53:01 2.8 12.68 172 61Tau1Ari 03:21:13.7 +21:08:49 5.3 0.40 165 PPM 092461 03:23:19.3 +20:58:13 8.0 0.35 165 PPM 092456 03:23:11.2 +21:34:06 9.4 0.28 165 4827_Dares 03:22:47.9 +21:18:10 15.6 165 Positions are for J2000