Occultation event with (4007) Euryalos, event index number 1035
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/06/06 18:59:50 UTC
J2000 position of star is 10:30:03.6 +13:41:01
Equinox of date position of star is 10:31:24.9 +13:33:10
Star is 53 degrees from the moon. Moon is 82% illuminated.
Stellar brightness G=12.9, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 12.1 per integration for unocculted signal
Expected flux drop is 95% with SNR of 11.5 for the occulted depth (per occulted point)
Apparent velocity is 19.2 km/sec on the sky relative to the star, or, 18.2 arcsec/hr.
Position angle of asteroid motion is 323.3 degrees
The recommended exposure time corresponds to 2.3 km per image.
The 1-sigma error in the time of the event is 2.2 seconds.
The 1-sigma cross-track error in the shadow position is 37.4 km.
The sky-plane scale is 3793.2 km/arcsec.
Diameter estimates:
51.3 km assuming a 5% albedo, aximum of 2.7 sec for a central chord
20.9 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 51.3 km used for deployment plan.
Star training set for 4007_Euryalos, (2025/06/06 19:00UT) Object RA Dec mag sep mel Regulus 10:09:43.4 +11:50:31 1.3 5.56 57 46 Leo 10:33:33.1 +14:00:21 5.5 0.69 52 PPM 127438 10:30:03.7 +13:09:30 7.6 0.51 53 PPM 127459 10:31:09.5 +14:00:47 9.1 0.46 53 PPM 127456 10:31:07.3 +13:17:43 11.2 0.27 53 4007_Euryalos 10:31:24.9 +13:33:10 16.0 52 Positions are for equinox of date
Star training set for 4007_Euryalos, (2025/06/06 19:00UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 5.56 57 46 Leo 10:32:11.7 +14:08:15 5.5 0.69 52 PPM 127438 10:28:42.4 +13:17:20 7.6 0.51 53 PPM 127459 10:29:48.0 +14:08:39 9.1 0.46 53 PPM 127456 10:29:46.0 +13:25:34 11.2 0.27 53 4007_Euryalos 10:30:03.6 +13:41:01 16.0 53 Positions are for J2000