RECON: TNO occultation with 303712

Event between (303712) 05PR21 and star GA0920:00028749 with event index number of 2297797

Geocentric closest approach at 2026/08/21 21:44:38 UTC

J2000 position of star is 00:18:34.2 +02:38:51
Equinox of date position of star is 00:19:42.1 +02:46:11
Stellar brightness G=13.8, use SENSEUP=64 with the MallinCam and and exposure time of 1 seconds with the QHY174 camera.
Star is 107 degrees from the moon. Moon is 67% illuminated.
TNO apparent brightness V=22.6

TNO is 42.5 AU from the Sun and 41.7 AU from the Earth.
The TNO is moving 19.2 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 191 seconds.
The 1-sigma cross-track error in the shadow position is 2639 km.

The TNO has an absolute magnitude Hv=6.3
Diameter=323.6 km assuming a 5% albedo -- 16.9 sec chord
Diameter=132.1 km assuming a 30% albedo -- 6.9 sec chord
Dynamical classification is CLASSICAL
 
 
 
 
 
 
 
 

Star training set for 303712, (2026/08/21 21:47UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:59:06.9 -29:28:49  1.2 37.63  75
Algenib        00:14:36.7 +15:19:53  2.8 12.60 111
44 Psc         00:26:46.3 +02:05:13  5.8  1.85 108
PPM 143346     00:19:09.8 +01:50:12  7.0  0.98 106
PPM 143333     00:18:41.0 +02:37:29  9.7  0.36 106
PPM 143366     00:20:12.1 +02:27:21 10.4  0.35 107
303712         00:19:56.3 +02:47:43 13.8       107
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 303712, (2026/08/21 21:47UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:57:39.6 -29:37:24  1.2 37.63  75
Algenib        00:13:14.2 +15:11:01  2.8 12.60 111
44 Psc         00:25:24.2 +01:56:22  5.8  1.85 108
PPM 143346     00:17:47.8 +01:41:20  7.0  0.98 106
PPM 143333     00:17:19.0 +02:28:37  9.7  0.36 106
PPM 143366     00:18:50.1 +02:18:29 10.4  0.35 107
303712         00:18:34.2 +02:38:51 13.8       107
Positions are for J2000

Event circumstances last updated at 2022/01/16 00:44:05 UT

Marc W. Buie, Southwest Research Institute

RECON