Occultation event with (4063) Euforbo, event index number 1668
Regions able to see the event: Australia
Geocentric closest approach at 2025/12/11 19:10:03 UTC
J2000 position of star is 13:19:01.3 +09:56:33
Equinox of date position of star is 13:20:19.0 +09:48:24
Star is 30 degrees from the moon. Moon is 51% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=14.6
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 5.6 per integration for unocculted signal
Expected flux drop is 29% with SNR of 1.6 for the occulted depth (per occulted point)
Apparent velocity is 26.1 km/sec on the sky relative to the star, or, 22.8 arcsec/hr.
Position angle of asteroid motion is 93.4 degrees
The recommended exposure time corresponds to 23.5 km per image.
The 1-sigma error in the time of the event is 0.6 seconds.
The 1-sigma cross-track error in the shadow position is 37.5 km.
The sky-plane scale is 4121.4 km/arcsec.
Diameter estimates:
109.2 km assuming a 5% albedo, aximum of 4.2 sec for a central chord
44.6 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 95.6 km used for deployment plan.
Star training set for 4063_Euforbo, (2025/12/11 19:10UT) Object RA Dec mag sep mel Arcturus 14:16:50.8 +19:02:55 0.0 16.50 46 Vindemiatrix 13:03:28.1 +10:49:13 2.8 4.27 26 59 Vir 13:18:03.8 +09:17:21 5.7 0.76 30 PPM 159664 13:20:56.8 +09:33:24 8.1 0.29 30 PPM 159644 13:20:07.3 +09:41:47 9.8 0.12 30 4063_Euforbo 13:20:19.0 +09:48:24 14.6 31 Positions are for equinox of date
Star training set for 4063_Euforbo, (2025/12/11 19:10UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 16.50 46 Vindemiatrix 13:02:10.1 +10:57:33 2.8 4.27 26 59 Vir 13:16:45.9 +09:25:31 5.7 0.76 30 PPM 159664 13:19:39.0 +09:41:33 8.1 0.29 30 PPM 159644 13:18:49.5 +09:49:56 9.8 0.12 30 4063_Euforbo 13:19:01.3 +09:56:33 14.6 30 Positions are for J2000