RECON: TNO occultation with 538691

Event between (538691) 16FW59 and star GA0780:04264761 with event index number of 2397551

Geocentric closest approach at 2023/02/19 20:26:45 UTC

J2000 position of star is 12:39:39.0 -11:10:14
Equinox of date position of star is 12:40:50.8 -11:17:48
Stellar brightness G=14.4, use SENSEUP=64 with the MallinCam and and exposure time of 1 seconds with the QHY174 camera.
Star is 130 degrees from the moon. Moon is 0% illuminated.
Apparent brightness V=22.7

Object is 45.1 AU from the Sun and 44.4 AU from the Earth.
Apparent velocity is 17.7 km/sec on the sky relative to the star, or, 2.0 arcsec/hr.
The 1-sigma error in the time of the event is 272 seconds.
The 1-sigma cross-track error in the shadow position is 2608 km.

The object has an absolute magnitude Hv=6.1
Diameter=359.8 km assuming a 5% albedo -- 20.4 sec chord
Diameter=146.9 km assuming a 30% albedo -- 8.3 sec chord
Dynamical classification is CLASSICAL
 
 
 
 
 
 
 
 

Star training set for 538691, (2023/02/19 20:21UT)
Object            RA         Dec     mag  sep  mel
Spica          13:26:24.9 -11:16:53  1.0 11.17 120
4Gam Crv       12:17:00.0 -17:40:13  2.6  8.60 130
PPM 226198     12:42:28.1 -13:08:27  6.0  1.89 128
PPM 226121     12:39:29.5 -12:30:44  8.0  1.26 129
PPM 226155     12:40:40.7 -11:17:46  9.3  0.04 130
538691         12:40:51.2 -11:17:50 14.4       130
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 538691, (2023/02/19 20:21UT)
Object            RA         Dec     mag  sep  mel
Spica          13:25:11.5 -11:09:41  1.0 11.17 120
4Gam Crv       12:15:48.1 -17:32:30  2.6  8.60 130
PPM 226198     12:41:15.7 -13:00:51  6.0  1.89 128
PPM 226121     12:38:17.2 -12:23:07  8.0  1.26 129
PPM 226155     12:39:28.4 -11:10:10  9.3  0.04 130
538691         12:39:39.0 -11:10:14 14.4       130
Positions are for J2000

Event circumstances last updated at 2023/01/09 03:33:28 UT

Marc W. Buie, Southwest Research Institute

RECON