RECON: TNO occultation with 126155

Event between (126155) 01YJ140 and star GA1060:03226455 with event index number of 2142923

Geocentric closest approach at 2025/10/15 17:11:06 UTC

J2000 position of star is 09:16:25.5 +16:21:07
Equinox of date position of star is 09:17:46.0 +16:15:00
Stellar brightness G=16.1, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 2 degrees from the moon. Moon is 30% illuminated.
Apparent brightness V=22.5

Object is 30.0 AU from the Sun and 30.3 AU from the Earth.
Apparent velocity is 17.8 km/sec on the sky relative to the star, or, 2.9 arcsec/hr.
The 1-sigma error in the time of the event is 139 seconds.
The 1-sigma cross-track error in the shadow position is 1528 km.

The object has an absolute magnitude Hv=7.5
Diameter=185.4 km assuming a 5% albedo -- 10.6 sec chord
Diameter=75.7 km assuming a 30% albedo -- 4.3 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 126155, (2025/10/15 17:07UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:09:44.6 +11:50:25  1.3 13.33  13
PPM 126361     09:22:40.6 +15:15:38  6.4  1.52   3
PPM 126293     09:19:04.0 +16:35:44  8.1  0.46   2
PPM 126289     09:18:48.0 +16:26:30  8.7  0.30   2
PPM 126265     09:17:23.7 +16:28:13 11.0  0.25   2
126155         09:17:51.4 +16:14:35 16.1         2
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, (2025/10/15 17:07UT)
Object            RA         Dec     mag  sep  mel
Regulus        10:08:21.9 +11:58:02  1.3 13.33  13
PPM 126361     09:21:15.3 +15:22:17  6.4  1.52   3
PPM 126293     09:17:38.1 +16:42:18  8.1  0.46   2
PPM 126289     09:17:22.1 +16:33:03  8.7  0.30   2
PPM 126265     09:15:57.7 +16:34:44 11.0  0.25   2
126155         09:16:25.5 +16:21:07 16.1         2
Positions are for J2000

Event circumstances last updated at 2024/03/04 05:36:30 UT

Marc W. Buie, Southwest Research Institute

RECON