Occultation event with (4489) Dracius, event index number 3515
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/03/27 07:20:47 UTC
J2000 position of star is 10:45:51.4 +35:05:27
Equinox of date position of star is 10:47:19.8 +34:57:08
Star is 38 degrees from the moon. Moon is 67% illuminated.
Stellar brightness G=14.2, apparent brightess of occulting body is G=14.1
Use an exposure time of 0.40 seconds with the standard RECON-QHY system.
SNR of 9.3 per integration for unocculted signal
Expected flux drop is 47% with SNR of 4.3 for the occulted depth (per occulted point)
Apparent velocity is 11.9 km/sec on the sky relative to the star, or, 13.9 arcsec/hr.
Position angle of asteroid motion is 89.3 degrees
The recommended exposure time corresponds to 4.8 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 36.8 km.
The sky-plane scale is 3075.3 km/arcsec.
Diameter estimates:
93.8 km assuming a 5% albedo, maximum of 7.9 sec for a central chord
38.3 km assuming a 30% albedo, maximum of 3.2 sec for a central chord
Cross-track diameter of 76.6 km used for deployment plan.
Star training set for 4489_Dracius, (2026/03/27 07:21UT) Object RA Dec mag sep mel Regulus 10:09:46.0 +11:50:17 1.3 24.64 34 68Del Leo 11:15:30.0 +20:22:46 2.6 15.84 46 46 LMi 10:54:46.3 +34:04:22 3.8 1.77 40 PPM 075421 10:44:35.5 +35:01:37 8.3 0.57 38 PPM 075462 10:48:12.5 +34:35:33 9.6 0.40 38 PPM 075449 10:47:19.5 +34:56:57 11.9 0.00 38 4489_Dracius 10:47:19.8 +34:57:08 14.1 39 Positions are for equinox of date
Star training set for 4489_Dracius, (2026/03/27 07:21UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 24.64 34 68Del Leo 11:14:06.8 +20:31:22 2.6 15.84 46 46 LMi 10:53:18.9 +34:12:46 3.8 1.77 40 PPM 075421 10:43:06.8 +35:09:54 8.3 0.57 38 PPM 075462 10:46:44.3 +34:43:53 9.6 0.40 38 PPM 075449 10:45:51.1 +35:05:16 11.9 0.00 38 4489_Dracius 10:45:51.4 +35:05:27 14.1 38 Positions are for J2000