RECON: TNO occultation with 55637

Event between (55637) 02UX25 and star GA0980:00322714 with event index number of 2250611

Geocentric closest approach at 2026/12/15 21:29:32 UTC

J2000 position of star is 03:41:13.6 +08:45:37
Equinox of date position of star is 03:42:32.1 +08:50:12
Stellar brightness G=14.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 77 degrees from the moon. Moon is 37% illuminated.
Apparent brightness V=19.8

Object is 39.4 AU from the Sun and 38.6 AU from the Earth.
Apparent velocity is 21.9 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 84 seconds.
The 1-sigma cross-track error in the shadow position is 1415 km.

The object has an absolute magnitude Hv=3.8
Diameter=1018.6 km assuming a 5% albedo -- 47.0 sec chord
Diameter=415.9 km assuming a 30% albedo -- 19.2 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 
 
 

Star training set for 55637, (2026/12/15 21:29UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:28.2 +16:33:41  0.8 15.42  91
Menkar         03:03:41.5 +04:11:38  2.5 10.74  67
6 Tau          03:34:03.6 +09:27:45  5.6  2.22  75
PPM 146841     03:44:04.6 +08:43:07  7.7  0.37  77
PPM 146803     03:41:55.9 +08:52:42 10.4  0.19  77
55637          03:42:41.1 +08:50:43 14.9        77
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 55637, (2026/12/15 21:29UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 15.42  91
Menkar         03:02:16.8 +04:05:21  2.5 10.74  67
6 Tau          03:32:35.9 +09:22:23  5.6  2.22  75
PPM 146841     03:42:37.2 +08:38:04  7.7  0.37  77
PPM 146803     03:40:28.4 +08:47:35 10.4  0.19  77
55637          03:41:13.6 +08:45:37 14.9        77
Positions are for J2000

Event circumstances last updated at 2024/03/05 04:53:12 UT

Marc W. Buie, Southwest Research Institute

RECON