RECON: TNO occultation with 523640

Event between (523640) 10RO64 and star GA0940:00189720 with event index number of 2626186

Geocentric closest approach at 2026/10/22 00:50:22 UTC

J2000 position of star is 02:13:21.1 +04:24:15
Equinox of date position of star is 02:14:36.6 +04:30:58
Stellar brightness G=15.7, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 57 degrees from the moon. Moon is 81% illuminated.
Apparent brightness V=21.2

Object is 41.4 AU from the Sun and 40.4 AU from the Earth.
Apparent velocity is 25.2 km/sec on the sky relative to the star, or, 3.1 arcsec/hr.
The 1-sigma error in the time of the event is 70 seconds.
The 1-sigma cross-track error in the shadow position is 1652 km.

The object has an absolute magnitude Hv=5.1
Diameter=539.5 km assuming a 5% albedo -- 22.7 sec chord
Diameter=220.3 km assuming a 30% albedo -- 9.3 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 
 
 

Star training set for 523640, (2026/10/22 00:49UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:27.7 +16:33:40  0.8 36.99  93
68Omi Cet      02:20:42.2 -02:51:25  2.0  7.53  57
PPM 145462     02:19:25.1 +01:52:58  5.6  2.89  57
PPM 145391     02:14:26.4 +04:24:38  8.5  0.14  57
523640         02:14:45.1 +04:31:43 15.7        57
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 523640, (2026/10/22 00:49UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 36.99  93
68Omi Cet      02:19:20.8 -02:58:45  2.0  7.53  57
PPM 145462     02:18:02.0 +01:45:36  5.6  2.89  57
PPM 145391     02:13:02.5 +04:17:10  8.5  0.14  57
523640         02:13:21.1 +04:24:15 15.7        57
Positions are for J2000

Event circumstances last updated at 2024/01/30 03:23:39 UT

Marc W. Buie, Southwest Research Institute

RECON