RECON: TNO occultation with 120061

Event between (120061) 03CO1 and star GA0580:44788723 with event index number of 2139050

Geocentric closest approach at 2025/05/27 17:24:40 UTC

J2000 position of star is 22:00:19.4 -30:53:32
Equinox of date position of star is 22:01:43.5 -30:46:30
Stellar brightness G=14.8, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 114 degrees from the moon. Moon is 1% illuminated.
Apparent brightness V=22.8

Object is 22.1 AU from the Sun and 21.9 AU from the Earth.
Apparent velocity is 9.6 km/sec on the sky relative to the star, or, 2.2 arcsec/hr.
The 1-sigma error in the time of the event is 107 seconds.
The 1-sigma cross-track error in the shadow position is 2831 km.

The object has an absolute magnitude Hv=9.1
Diameter=93.3 km assuming a 5% albedo -- 9.6 sec chord
Diameter=38.1 km assuming a 30% albedo -- 3.9 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 120061, (2025/05/27 17:25UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:59:02.8 -29:29:13  1.2 12.44 102
PPM 301991     21:57:24.1 -30:29:04  6.5  0.99 115
PPM 302075     22:01:24.0 -31:24:12  7.5  0.64 114
PPM 302071     22:01:20.9 -30:58:57 10.0  0.23 114
120061         22:01:47.6 -30:46:10 14.8       114
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 120061, (2025/05/27 17:25UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:57:39.6 -29:37:24  1.2 12.44 102
PPM 301991     21:55:55.7 -30:36:22  6.5  0.99 115
PPM 302075     21:59:55.6 -31:31:33  7.5  0.64 114
PPM 302071     21:59:52.6 -31:06:18 10.0  0.23 114
120061         22:00:19.4 -30:53:32 14.8       114
Positions are for J2000

Event circumstances last updated at 2024/03/21 22:30:02 UT

Marc W. Buie, Southwest Research Institute

RECON