Occultation event with (1867) Deiphobus, event index number 1661
Regions able to see the event: US
Geocentric closest approach at 2025/12/09 22:03:57 UTC
J2000 position of star is 02:43:54.1 +41:33:30
Equinox of date position of star is 02:45:34.2 +41:40:01
Star is 92 degrees from the moon. Moon is 70% illuminated.
Stellar brightness G=15.0, apparent brightess of occulting body is G=13.5
Use an exposure time of 1.65 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 20% with SNR of 2.0 for the occulted depth (per occulted point)
Apparent velocity is 17.4 km/sec on the sky relative to the star, or, 19.4 arcsec/hr.
Position angle of asteroid motion is 39.1 degrees
The recommended exposure time corresponds to 28.6 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 20.3 km.
The sky-plane scale is 3217.5 km/arcsec.
Diameter estimates:
130.0 km assuming a 5% albedo, aximum of 7.5 sec for a central chord
53.1 km assuming a 30% albedo, maximum of 3.1 sec for a central chord
Cross-track diameter of 118.2 km used for deployment plan.
Star training set for 1867_Deiphobus, (2025/12/09 22:04UT) Object RA Dec mag sep mel Aldebaran 04:37:24.7 +16:33:33 0.8 34.72 75 Algol 03:09:52.0 +41:03:13 2.1 4.60 88 PPM 067541 02:38:59.2 +40:00:27 6.3 2.07 94 PPM 045422 02:45:23.9 +41:36:24 7.2 0.07 92 1867_Deiphobus 02:45:34.2 +41:40:01 13.5 92 Positions are for equinox of date
Star training set for 1867_Deiphobus, (2025/12/09 22:04UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 34.72 75 Algol 03:08:10.1 +40:57:20 2.1 4.60 88 PPM 067541 02:37:20.9 +39:53:46 6.3 2.07 94 PPM 045422 02:43:44.0 +41:29:52 7.2 0.07 92 1867_Deiphobus 02:43:54.1 +41:33:30 13.5 92 Positions are for J2000