RECON: TNO occultation with 531224

Event between (531224) 12HK85 and star GA0740:05357241 with event index number of 1601213

Geocentric closest approach at 2021/01/22 01:03:58 UTC

J2000 position of star is 15:06:14.5 -15:04:05
Equinox of date position of star is 15:07:24.7 -15:08:55
Stellar brightness G=16.6, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 176 degrees from the moon. Moon is 61% illuminated.
TNO apparent brightness V=22.9

TNO is 39.0 AU from the Sun and 39.3 AU from the Earth.
The TNO is moving 14.2 km/sec on the sky relative to the star, or, 1.8 arcsec/hr.
The 1-sigma error in the time of the event is 202 seconds.
The 1-sigma cross-track error in the shadow position is 1734 km.

The TNO has an absolute magnitude Hv=6.8
Diameter=259.4 km assuming a 5% albedo -- 18.3 sec chord
Diameter=105.9 km assuming a 30% albedo -- 7.5 sec chord
Dynamical classification is SCATNEAR
 
 
 
 
 
 
 
 

Star training set for 531224, (2021/01/22 01:04UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:42.1 -26:28:37  0.9 22.47 154
27Bet Lib      15:18:08.6 -09:27:34  2.6  6.26 173
21Nu Lib       15:07:48.3 -16:20:14  5.2  1.19 176
PPM 229720     15:05:54.6 -15:04:42  8.1  0.37 177
PPM 229744     15:07:03.1 -15:24:26  9.5  0.27 176
531224         15:07:24.8 -15:08:55 16.6       176
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, (2021/01/22 01:04UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 22.47 154
27Bet Lib      15:17:00.3 -09:22:59  2.6  6.26 173
21Nu Lib       15:06:37.6 -16:15:25  5.2  1.19 176
PPM 229720     15:04:44.4 -14:59:51  8.1  0.37 177
PPM 229744     15:05:52.7 -15:19:36  9.5  0.27 176
531224         15:06:14.5 -15:04:05 16.6       176
Positions are for J2000

Event circumstances last updated at 2021/01/18 20:48:42 UT

Marc W. Buie, Southwest Research Institute

RECON