RECON: TNO occultation with 542889

Event between (542889) 13MY11 and star GA0760:00019894 with event index number of 2257371

Geocentric closest approach at 2026/07/02 22:25:07 UTC

J2000 position of star is 00:14:22.5 -13:57:12
Equinox of date position of star is 00:15:29.8 -13:49:51
Stellar brightness G=16.4, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 45 degrees from the moon. Moon is 92% illuminated.
TNO apparent brightness V=22.9

TNO is 26.6 AU from the Sun and 26.3 AU from the Earth.
The TNO is moving 7.3 km/sec on the sky relative to the star, or, 1.4 arcsec/hr.
The 1-sigma error in the time of the event is 257 seconds.
The 1-sigma cross-track error in the shadow position is 3825 km.

The TNO has an absolute magnitude Hv=8.5
Diameter=120.2 km assuming a 5% albedo -- 16.4 sec chord
Diameter=49.1 km assuming a 30% albedo -- 6.7 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 542889, (2026/07/02 22:24UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:59:06.4 -29:28:52  1.2 23.65  28
Diphda         00:44:55.0 -17:50:30  2.0  8.10  52
PPM 208443     00:12:04.2 -12:25:58  5.8  1.64  45
PPM 208544     00:16:09.0 -14:01:51  7.3  0.25  45
542889         00:15:43.4 -13:48:22 16.4        46
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 542889, (2026/07/02 22:24UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:57:39.6 -29:37:24  1.2 23.65  28
Diphda         00:43:35.7 -17:59:11  2.0  8.10  52
PPM 208443     00:10:43.1 -12:34:48  5.8  1.64  45
PPM 208544     00:14:48.1 -14:10:41  7.3  0.25  45
542889         00:14:22.5 -13:57:12 16.4        45
Positions are for J2000

Event circumstances last updated at 2022/01/14 23:58:58 UT

Marc W. Buie, Southwest Research Institute

RECON