Occultation event with (4057) Demophon, event index number 3384
Regions able to see the event: Australia
Geocentric closest approach at 2026/03/09 19:05:09 UTC
J2000 position of star is 11:42:19.8 +03:54:21
Equinox of date position of star is 11:43:40.5 +03:45:37
Star is 68 degrees from the moon. Moon is 65% illuminated.
Stellar brightness G=13.1, apparent brightess of occulting body is G=14.9
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 10.0 per integration for unocculted signal
Expected flux drop is 83% with SNR of 8.3 for the occulted depth (per occulted point)
Apparent velocity is 16.7 km/sec on the sky relative to the star, or, 20.0 arcsec/hr.
Position angle of asteroid motion is 111.7 degrees
The recommended exposure time corresponds to 2.0 km per image.
The 1-sigma error in the time of the event is 1.8 seconds.
The 1-sigma cross-track error in the shadow position is 27.1 km.
The sky-plane scale is 3011.1 km/arcsec.
Diameter estimates:
53.2 km assuming a 5% albedo, maximum of 3.2 sec for a central chord
21.7 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 45.7 km used for deployment plan.
Star training set for 4057_Demophon, (2026/03/09 19:05UT) Object RA Dec mag sep mel Regulus 10:09:45.8 +11:50:18 1.3 24.60 92 Denebola 11:50:23.6 +14:25:32 2.1 10.79 72 89 Leo 11:35:42.4 +02:54:52 6.2 2.16 69 PPM 158108 11:42:58.9 +04:26:42 8.0 0.71 68 PPM 158105 11:42:53.9 +03:42:18 8.9 0.20 68 PPM 158129 11:43:56.7 +03:36:39 11.5 0.16 67 4057_Demophon 11:43:40.5 +03:45:37 14.9 67 Positions are for equinox of date
Star training set for 4057_Demophon, (2026/03/09 19:05UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 24.60 92 Denebola 11:49:02.7 +14:34:16 2.1 10.79 72 89 Leo 11:34:21.6 +03:03:34 6.2 2.16 69 PPM 158108 11:41:38.2 +04:35:25 8.0 0.71 68 PPM 158105 11:41:33.2 +03:51:01 8.9 0.20 68 PPM 158129 11:42:36.0 +03:45:22 11.5 0.16 67 4057_Demophon 11:42:19.8 +03:54:21 14.9 68 Positions are for J2000