RECON: TNO occultation with 523629

Event between (523629) 08SP266 and star GA0840:00200690 with event index number of 2626301

Geocentric closest approach at 2025/09/21 20:15:10 UTC

J2000 position of star is 02:31:51.5 -05:07:34
Equinox of date position of star is 02:33:03.6 -05:01:15
Stellar brightness G=15.5, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 141 degrees from the moon. Moon is 0% illuminated.
Apparent brightness V=21.5

Object is 36.2 AU from the Sun and 35.4 AU from the Earth.
Apparent velocity is 20.2 km/sec on the sky relative to the star, or, 2.8 arcsec/hr.
The 1-sigma error in the time of the event is 90 seconds.
The 1-sigma cross-track error in the shadow position is 1484 km.

The object has an absolute magnitude Hv=5.8
Diameter=403.7 km assuming a 5% albedo -- 20.7 sec chord
Diameter=164.8 km assuming a 30% albedo -- 8.4 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 
 
 

Star training set for 523629, (2025/09/21 20:14UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:24.0 +16:33:33  0.8 37.53 109
68Omi Cet      02:20:38.9 -02:51:43  2.0  3.79 144
81 Cet         02:38:59.7 -03:17:10  5.6  2.26 139
PPM 184694     02:31:43.7 -04:55:05  8.1  0.37 141
PPM 184723     02:32:48.1 -04:59:45  9.3  0.09 141
523629         02:33:08.7 -05:00:49 15.5       140
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 523629, (2025/09/21 20:14UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 37.53 109
68Omi Cet      02:19:20.8 -02:58:45  2.0  3.79 144
81 Cet         02:37:41.9 -03:23:48  5.6  2.26 139
PPM 184694     02:30:26.4 -05:01:52  8.1  0.37 141
PPM 184723     02:31:30.8 -05:06:31  9.3  0.09 141
523629         02:31:51.5 -05:07:34 15.5       141
Positions are for J2000

Event circumstances last updated at 2024/01/08 05:15:43 UT

Marc W. Buie, Southwest Research Institute

RECON