RECON: TNO occultation with 531224

Event between (531224) 12HK85 and star GA0720:05623402 with event index number of 2442218

Geocentric closest approach at 2026/01/28 16:33:25 UTC

J2000 position of star is 15:40:08.7 -17:51:14
Equinox of date position of star is 15:41:32.6 -17:55:54
Stellar brightness G=16.6, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 164 degrees from the moon. Moon is 77% illuminated.
Apparent brightness V=22.8

Object is 38.5 AU from the Sun and 38.8 AU from the Earth.
Apparent velocity is 15.3 km/sec on the sky relative to the star, or, 2.0 arcsec/hr.
The 1-sigma error in the time of the event is 350 seconds.
The 1-sigma cross-track error in the shadow position is 3184 km.

The object has an absolute magnitude Hv=6.8
Diameter=259.4 km assuming a 5% albedo -- 16.9 sec chord
Diameter=105.9 km assuming a 30% albedo -- 6.9 sec chord
Dynamical classification is SCATNEAR
 
 
 
 
 
 
 
 

Star training set for 531224, (2026/01/28 16:33UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:00.6 -26:29:15  0.9 14.26 178
8Bet1Sco       16:06:57.5 -19:52:29  2.6  6.29 169
41 Lib         15:40:24.9 -19:23:09  5.3  1.48 164
PPM 230521     15:40:10.6 -17:44:55  7.3  0.39 163
PPM 230563     15:41:51.0 -17:54:19  8.9  0.06 164
531224         15:41:38.1 -17:56:12 16.6       164
Positions are for equinox of date

Azimuth is measured in degrees eastward from north. North is at an azimuth of 0, due East is at an azimuth of 90 degrees, due South is 180, and due West is 270.

Do not use the listing below for the RECON CPC 1100 telescopes. This is provided for other non-team facilities.

Star training set for 531224, (2026/01/28 16:33UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 14.26 178
8Bet1Sco       16:05:26.2 -19:48:20  2.6  6.29 169
41 Lib         15:38:54.7 -19:18:08  5.3  1.48 164
PPM 230521     15:38:41.3 -17:39:54  7.3  0.39 163
PPM 230563     15:40:21.5 -17:49:22  8.9  0.06 164
531224         15:40:08.7 -17:51:14 16.6       164
Positions are for J2000

Event circumstances last updated at 2024/06/18 21:24:02 UT

Marc W. Buie, Southwest Research Institute

RECON