RECON: TNO occultation with 559178

Event between (559178) 15BM518 and star GA0760:04669136 with event index number of 2638983

Geocentric closest approach at 2026/04/04 18:10:15 UTC

J2000 position of star is 12:36:01.4 -13:07:22
Equinox of date position of star is 12:37:17.8 -13:15:26
Stellar brightness G=16.1, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 32 degrees from the moon. Moon is 93% illuminated.
Apparent brightness V=21.7

Object is 34.4 AU from the Sun and 33.4 AU from the Earth.
Apparent velocity is 24.6 km/sec on the sky relative to the star, or, 3.7 arcsec/hr.
The 1-sigma error in the time of the event is 97 seconds.
The 1-sigma cross-track error in the shadow position is 1857 km.

The object has an absolute magnitude Hv=6.4
Diameter=310.5 km assuming a 5% albedo -- 12.7 sec chord
Diameter=126.7 km assuming a 30% albedo -- 5.2 sec chord
Dynamical classification is 4:3E
 
 
 
 
 
 
 
 

Star training set for 559178, (2026/04/04 18:07UT)
Object            RA         Dec     mag  sep  mel
Spica          13:26:34.8 -11:17:51  1.0 12.17  22
4Gam Crv       12:17:09.7 -17:41:15  2.6  6.58  35
PPM 225991     12:33:57.8 -14:00:15  6.2  1.11  32
PPM 226121     12:39:39.2 -12:31:46  8.0  0.92  31
PPM 226096     12:38:03.5 -13:20:34  9.8  0.18  32
559178         12:37:23.4 -13:16:01 16.1        31
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 559178, (2026/04/04 18:07UT)
Object            RA         Dec     mag  sep  mel
Spica          13:25:11.5 -11:09:41  1.0 12.17  22
4Gam Crv       12:15:48.1 -17:32:30  2.6  6.58  35
PPM 225991     12:32:35.8 -13:51:34  6.2  1.11  32
PPM 226121     12:38:17.2 -12:23:07  8.0  0.92  31
PPM 226096     12:36:41.4 -13:11:55  9.8  0.18  32
559178         12:36:01.4 -13:07:22 16.1        32
Positions are for J2000

Event circumstances last updated at 2024/06/18 21:26:08 UT

Marc W. Buie, Southwest Research Institute

RECON