RECON: TNO occultation with 42301

Event between (42301) 01UR163 and star GA1060:00268578 with event index number of 1414284

Geocentric closest approach at 2025/07/11 02:03:42 UTC

J2000 position of star is 02:43:35.0 +16:36:55
Equinox of date position of star is 02:44:55.7 +16:43:00
Stellar brightness G=16.1, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 112 degrees from the moon. Moon is 100% illuminated.
Apparent brightness V=21.7

Object is 54.6 AU from the Sun and 55.0 AU from the Earth.
Apparent velocity is 16.0 km/sec on the sky relative to the star, or, 1.4 arcsec/hr.
The 1-sigma error in the time of the event is 144 seconds.
The 1-sigma cross-track error in the shadow position is 2029 km.

The object has an absolute magnitude Hv=4.2
Diameter=867.0 km assuming a 5% albedo -- 55.3 sec chord
Diameter=353.9 km assuming a 30% albedo -- 22.6 sec chord
Dynamical classification is 9:4EEEEE
 
 
 
 
 
 
 
 

Star training set for 42301, (2025/07/11 02:07UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:23.3 +16:33:31  0.8 26.90 137
Hamal          02:08:37.0 +23:34:55  2.0 10.95 106
36 Ari         02:45:44.9 +17:52:14  6.4  1.16 112
PPM 118470     02:43:45.6 +17:04:00  8.2  0.45 112
PPM 118486     02:45:08.8 +16:45:37  9.9  0.05 112
42301          02:45:00.2 +16:43:20 16.1       112
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 42301, (2025/07/11 02:07UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 26.90 137
Hamal          02:07:10.7 +23:27:42  2.0 10.95 106
36 Ari         02:44:19.2 +17:45:49  6.4  1.16 112
PPM 118470     02:42:20.3 +16:57:32  8.2  0.45 112
PPM 118486     02:43:43.6 +16:39:12  9.9  0.05 112
42301          02:43:35.0 +16:36:55 16.1       112
Positions are for J2000

Event circumstances last updated at 2024/03/02 06:30:21 UT

Marc W. Buie, Southwest Research Institute

RECON