RECON: TNO occultation with 612218

Event between (612218) 01KD77 and star GA0680:40762409 with event index number of 2810992

Geocentric closest approach at 2025/11/05 10:18:32 UTC

J2000 position of star is 19:26:21.9 -20:54:36
Equinox of date position of star is 19:27:41.2 -20:51:50
Stellar brightness G=16.5, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 111 degrees from the moon. Moon is 100% illuminated.
TNO apparent brightness V=21.5

TNO is 37.1 AU from the Sun and 37.5 AU from the Earth.
The TNO is moving 17.1 km/sec on the sky relative to the star, or, 2.3 arcsec/hr.
The 1-sigma error in the time of the event is 1536 seconds.
The 1-sigma cross-track error in the shadow position is 5345 km.

The TNO has an absolute magnitude Hv=5.6
Diameter=455.0 km assuming a 5% albedo -- 26.7 sec chord
Diameter=185.8 km assuming a 30% albedo -- 10.9 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 612218, (2025/11/05 10:19UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:59.8 -26:29:13  0.9 40.70 152
Nunki          18:56:52.0 -26:15:44  2.0  8.93 119
50 Sgr         19:27:51.5 -21:43:24  5.6  0.87 111
PPM 269786     19:27:59.6 -21:11:34  7.3  0.34 111
PPM 269787     19:28:05.2 -20:32:05  8.7  0.33 111
612218         19:27:53.7 -20:51:24 16.5       111
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 612218, (2025/11/05 10:19UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 40.70 152
Nunki          18:55:15.9 -26:17:49  2.0  8.93 119
50 Sgr         19:26:19.2 -21:46:36  5.6  0.87 111
PPM 269786     19:26:27.7 -21:14:46  7.3  0.34 111
PPM 269787     19:26:33.7 -20:35:18  8.7  0.33 111
612218         19:26:21.9 -20:54:36 16.5       111
Positions are for J2000

Event circumstances last updated at 2022/05/04 23:03:21 UT

Marc W. Buie, Southwest Research Institute

RECON