Occultation event with (4827) Dares, event index number 1146
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/07/16 07:34:04 UTC
J2000 position of star is 03:02:27.1 +20:15:37
Equinox of date position of star is 03:03:54.7 +20:21:34
Star is 47 degrees from the moon. Moon is 69% illuminated.
Stellar brightness G=12.5, apparent brightess of occulting body is G=16.1
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 15.5 per integration for unocculted signal
Expected flux drop is 97% with SNR of 15.0 for the occulted depth (per occulted point)
Apparent velocity is 25.8 km/sec on the sky relative to the star, or, 24.4 arcsec/hr.
The recommended exposure time corresponds to 3.1 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 11.6 km.
The sky-plane scale is 3811.1 km/arcsec.
Diameter estimates:
46.3 km assuming a 5% albedo, aximum of 1.8 sec for a central chord
18.9 km assuming a 30% albedo, maximum of 0.7 sec for a central chord
Cross-track diameter of 46.3 km used for deployment plan.
Star training set for 4827_Dares, (2025/07/16 07:34UT) Object RA Dec mag sep mel Aldebaran 04:37:23.3 +16:33:31 0.8 22.47 68 Hamal 02:08:37.1 +23:34:55 2.0 13.21 37 48Eps Ari 03:00:40.6 +21:26:27 5.6 1.32 47 PPM 118722 03:00:37.8 +20:05:25 7.7 0.82 46 PPM 092176 03:04:37.2 +20:26:06 9.2 0.18 47 4827_Dares 03:03:54.7 +20:21:34 16.1 48 Positions are for equinox of date
Star training set for 4827_Dares, (2025/07/16 07:34UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 22.47 68 Hamal 02:07:10.8 +23:27:41 2.0 13.21 37 48Eps Ari 02:59:12.6 +21:20:25 5.6 1.32 47 PPM 118722 02:59:10.5 +19:59:23 7.7 0.82 46 PPM 092176 03:03:09.6 +20:20:11 9.2 0.18 47 4827_Dares 03:02:27.1 +20:15:37 16.1 47 Positions are for J2000