RECON: TNO occultation with 559180

Event between (559180) 15BT518 and star GA0800:04650185 with event index number of 2654677

Geocentric closest approach at 2026/04/09 21:59:17 UTC

J2000 position of star is 14:59:48.7 -09:48:24
Equinox of date position of star is 15:01:07.9 -09:54:10
Stellar brightness G=15.2, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 62 degrees from the moon. Moon is 53% illuminated.
Apparent brightness V=22.2

Object is 42.6 AU from the Sun and 41.7 AU from the Earth.
Apparent velocity is 22.0 km/sec on the sky relative to the star, or, 2.6 arcsec/hr.
The 1-sigma error in the time of the event is 143 seconds.
The 1-sigma cross-track error in the shadow position is 2032 km.

The object has an absolute magnitude Hv=5.9
Diameter=394.5 km assuming a 5% albedo -- 18.2 sec chord
Diameter=161.0 km assuming a 30% albedo -- 7.4 sec chord
Dynamical classification is CLASSICAL
 
 
 
 
 
 
 
 

Star training set for 559180, (2026/04/09 21:58UT)
Object            RA         Dec     mag  sep  mel
Spica          13:26:34.9 -11:17:51  1.0 23.29  83
27Bet Lib      15:18:25.5 -09:28:41  2.6  4.26  59
19Del Lib      15:02:22.8 -08:37:18  4.9  1.32  63
PPM 198126     15:01:48.0 -09:14:21  8.3  0.69  62
PPM 198120     15:01:02.1 -09:57:33  9.1  0.07  62
559180         15:01:13.8 -09:54:36 15.2        62
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 559180, (2026/04/09 21:58UT)
Object            RA         Dec     mag  sep  mel
Spica          13:25:11.5 -11:09:41  1.0 23.29  83
27Bet Lib      15:17:00.3 -09:22:59  2.6  4.26  59
19Del Lib      15:00:58.3 -08:31:08  4.9  1.32  63
PPM 198126     15:00:23.2 -09:08:10  8.3  0.69  62
PPM 198120     14:59:37.0 -09:51:21  9.1  0.07  62
559180         14:59:48.7 -09:48:24 15.2        62
Positions are for J2000

Event circumstances last updated at 2024/06/18 21:26:10 UT

Marc W. Buie, Southwest Research Institute

RECON