RECON: TNO occultation with 126155

Event between (126155) 01YJ140 and star GA1060:03190624 with event index number of 2142912

Geocentric closest approach at 2025/05/21 16:20:27 UTC

J2000 position of star is 08:58:19.8 +17:46:07
Equinox of date position of star is 08:59:41.4 +17:40:26
Stellar brightness G=15.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 146 degrees from the moon. Moon is 37% illuminated.
Apparent brightness V=22.5

Object is 29.9 AU from the Sun and 30.2 AU from the Earth.
Apparent velocity is 15.1 km/sec on the sky relative to the star, or, 2.5 arcsec/hr.
The 1-sigma error in the time of the event is 115 seconds.
The 1-sigma cross-track error in the shadow position is 1234 km.

The object has an absolute magnitude Hv=7.5
Diameter=185.4 km assuming a 5% albedo -- 12.5 sec chord
Diameter=75.7 km assuming a 30% albedo -- 5.1 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 126155, (2025/05/21 16:18UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:09:43.3 +11:50:32  1.3 17.88 164
PPM 125810     08:52:11.6 +18:44:09  6.2  2.09 144
PPM 125941     08:58:11.7 +17:22:56  8.4  0.47 146
PPM 125978     09:00:17.0 +17:52:19  9.3  0.24 146
126155         08:59:45.5 +17:40:09 15.9       146
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 126155, (2025/05/21 16:18UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:08:21.9 +11:58:02  1.3 17.88 164
PPM 125810     08:50:45.0 +18:49:55  6.2  2.09 144
PPM 125941     08:56:46.0 +17:28:52  8.4  0.47 146
PPM 125978     08:58:51.1 +17:58:18  9.3  0.24 146
126155         08:58:19.8 +17:46:07 15.9       146
Positions are for J2000

Event circumstances last updated at 2024/03/04 05:32:31 UT

Marc W. Buie, Southwest Research Institute

RECON