Occultation event with (4057) Demophon, event index number 1510
Regions able to see the event: Senegal
Geocentric closest approach at 2025/11/14 04:53:13 UTC
J2000 position of star is 11:37:02.4 +04:22:06
Equinox of date position of star is 11:38:22.2 +04:13:30
Star is 8 degrees from the moon. Moon is 30% illuminated.
Stellar brightness G=11.1, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 35.3 per integration for unocculted signal
Expected flux drop is 99% with SNR of 34.9 for the occulted depth (per occulted point)
Apparent velocity is 28.3 km/sec on the sky relative to the star, or, 25.6 arcsec/hr.
Position angle of asteroid motion is 112.9 degrees
The recommended exposure time corresponds to 3.4 km per image.
The 1-sigma error in the time of the event is 1.0 seconds.
The 1-sigma cross-track error in the shadow position is 25.4 km.
The sky-plane scale is 3974.4 km/arcsec.
Diameter estimates:
53.2 km assuming a 5% albedo, aximum of 1.9 sec for a central chord
21.7 km assuming a 30% albedo, maximum of 0.8 sec for a central chord
Cross-track diameter of 45.7 km used for deployment plan.
Star training set for 4057_Demophon, (2025/11/14 04:53UT) Object RA Dec mag sep mel Regulus 10:09:44.8 +11:50:23 1.3 23.20 15 Denebola 11:50:22.7 +14:25:39 2.1 10.62 14 89 Leo 11:35:41.4 +02:54:58 6.2 1.47 8 PPM 158062 11:40:04.3 +04:17:00 8.3 0.43 8 PPM 158046 11:39:07.8 +04:10:47 10.3 0.19 8 4057_Demophon 11:38:22.2 +04:13:30 15.9 8 Positions are for equinox of date
Star training set for 4057_Demophon, (2025/11/14 04:53UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 23.20 15 Denebola 11:49:02.7 +14:34:16 2.1 10.62 14 89 Leo 11:34:21.6 +03:03:34 6.2 1.47 8 PPM 158062 11:38:44.5 +04:25:36 8.3 0.43 8 PPM 158046 11:37:48.0 +04:19:23 10.3 0.19 8 4057_Demophon 11:37:02.4 +04:22:06 15.9 8 Positions are for J2000