Occultation event with (12444) Prothoon, event index number 3175
Regions able to see the event: UAE
Geocentric closest approach at 2026/01/27 17:16:38 UTC
J2000 position of star is 01:57:12.6 +07:30:26
Equinox of date position of star is 01:58:35.1 +07:38:01
Star is 29 degrees from the moon. Moon is 67% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=15.8
Use an exposure time of 1.05 seconds with the standard RECON-QHY system.
SNR of 3.7 per integration for unocculted signal
Expected flux drop is 38% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 15.1 km/sec on the sky relative to the star, or, 13.7 arcsec/hr.
Position angle of asteroid motion is 86.4 degrees
The recommended exposure time corresponds to 15.8 km per image.
The 1-sigma error in the time of the event is 0.3 seconds.
The 1-sigma cross-track error in the shadow position is 30.0 km.
The sky-plane scale is 3953.7 km/arcsec.
Diameter estimates:
62.2 km assuming a 5% albedo, maximum of 4.1 sec for a central chord
25.4 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 63.8 km used for deployment plan.
Star training set for 12444_Prothoon, (2026/01/27 17:17UT) Object RA Dec mag sep mel Aldebaran 04:37:25.2 +16:33:34 0.8 39.76 16 68Omi Cet 02:20:39.9 -02:51:38 2.0 11.85 33 110Omi Psc 01:46:46.5 +09:17:17 4.3 3.36 31 PPM 145171 02:00:18.8 +06:47:59 8.5 0.94 30 PPM 145170 02:00:12.3 +07:46:16 9.3 0.42 29 PPM 145143 01:58:05.5 +07:37:00 10.1 0.12 29 12444_Prothoon 01:58:35.1 +07:38:01 15.8 29 Positions are for equinox of date
Star training set for 12444_Prothoon, (2026/01/27 17:17UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 39.76 16 68Omi Cet 02:19:20.8 -02:58:46 2.0 11.85 33 110Omi Psc 01:45:23.8 +09:09:29 4.3 3.36 31 PPM 145171 01:58:56.6 +06:40:26 8.5 0.94 30 PPM 145170 01:58:49.7 +07:38:43 9.3 0.42 29 PPM 145143 01:56:43.1 +07:29:25 10.1 0.12 29 12444_Prothoon 01:57:12.6 +07:30:26 15.8 29 Positions are for J2000