Occultation event with (4543) Phoinix, event index number 1173
Regions able to see the event: SAmericaS
Geocentric closest approach at 2025/07/27 22:13:52 UTC
J2000 position of star is 11:35:24.9 -06:51:16
Equinox of date position of star is 11:36:43.1 -06:59:46
Star is 16 degrees from the moon. Moon is 11% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=15.8
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 38% with SNR of 1.2 for the occulted depth (per occulted point)
Apparent velocity is 30.1 km/sec on the sky relative to the star, or, 24.8 arcsec/hr.
Position angle of asteroid motion is 335.8 degrees
The recommended exposure time corresponds to 25.6 km per image.
The 1-sigma error in the time of the event is 1.5 seconds.
The 1-sigma cross-track error in the shadow position is 35.8 km.
The sky-plane scale is 4374.0 km/arcsec.
Diameter estimates:
66.7 km assuming a 5% albedo, aximum of 2.2 sec for a central chord
27.2 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 66.7 km used for deployment plan.
Star training set for 4543_Phoinix, (2025/07/27 22:14UT) Object RA Dec mag sep mel Spica 13:26:32.6 -11:17:38 1.0 27.43 40 4Gam Crv 12:17:07.5 -17:41:02 2.6 14.54 31 PPM 194572 11:34:05.6 -07:58:08 5.8 1.17 17 PPM 194587 11:34:56.0 -06:40:42 7.9 0.55 16 PPM 194619 11:36:53.4 -07:04:07 9.5 0.08 16 4543_Phoinix 11:36:43.1 -06:59:46 15.8 17 Positions are for equinox of date
Star training set for 4543_Phoinix, (2025/07/27 22:14UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 27.43 40 4Gam Crv 12:15:48.1 -17:32:30 2.6 14.54 31 PPM 194572 11:32:47.5 -07:49:39 5.8 1.17 17 PPM 194587 11:33:37.8 -06:32:13 7.9 0.55 16 PPM 194619 11:35:35.2 -06:55:37 9.5 0.08 16 4543_Phoinix 11:35:24.9 -06:51:16 15.8 16 Positions are for J2000