Occultation event with (12444) Prothoon, event index number 4474
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/10/24 08:27:28 UTC
J2000 position of star is 04:20:59.4 +04:29:29
Equinox of date position of star is 04:22:24.4 +04:33:13
Star is 60 degrees from the moon. Moon is 96% illuminated.
Stellar brightness G=16.2, apparent brightess of occulting body is G=15.3
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 3.4 per integration for unocculted signal
Expected flux drop is 30% with SNR of 1.0 for the occulted depth (per occulted point)
Apparent velocity is 17.4 km/sec on the sky relative to the star, or, 18.4 arcsec/hr.
Position angle of asteroid motion is 44.9 degrees
The recommended exposure time corresponds to 15.7 km per image.
The 1-sigma error in the time of the event is 0.9 seconds.
The 1-sigma cross-track error in the shadow position is 27.4 km.
The sky-plane scale is 3401.7 km/arcsec.
Diameter estimates:
62.2 km assuming a 5% albedo, maximum of 3.6 sec for a central chord
25.4 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 63.8 km used for deployment plan.
Star training set for 12444_Prothoon, (2026/10/24 08:27UT) Object RA Dec mag sep mel Aldebaran 04:37:27.7 +16:33:40 0.8 12.56 63 67Bet Eri 05:09:10.2 -05:03:14 2.8 15.12 72 45 Tau 04:12:46.1 +05:35:27 5.7 2.61 57 PPM 147464 04:23:05.2 +03:59:57 8.5 0.58 60 PPM 147443 04:22:07.5 +04:19:39 9.3 0.24 60 12444_Prothoon 04:22:24.4 +04:33:13 15.3 60 Positions are for equinox of date
Star training set for 12444_Prothoon, (2026/10/24 08:27UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 12.56 63 67Bet Eri 05:07:50.8 -05:05:13 2.8 15.12 72 45 Tau 04:11:20.5 +05:31:23 5.7 2.61 57 PPM 147464 04:21:40.5 +03:56:15 8.5 0.58 60 PPM 147443 04:20:42.6 +04:15:55 9.3 0.24 60 12444_Prothoon 04:20:59.4 +04:29:29 15.3 60 Positions are for J2000