RECON: TNO occultation with 309139

Event between (309139) 06XQ51 and star UC4-376-052578 with event index number of 95054

Geocentric closest approach at 2017/12/17 06:39:58 UTC

J2000 position of star is 08:36:48.9 -14:55:21
Equinox of date position of star is 08:37:34.3 -14:58:47
Stellar brightness R=14.8
Star is 116 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=22.4

TNO is 17.5 AU from the Sun and 17.0 AU from the Earth.
The TNO is moving 18.3 km/sec on the sky relative to the star, or, 5.4 arcsec/hr.
The 1-sigma error in the time of the event is 337 seconds.
The 1-sigma cross-track error in the shadow position is 3503 km.

The TNO has an absolute magnitude Hv=9.8
Diameter=66.1 km assuming a 5% albedo -- 3.6 sec chord
Diameter=27.0 km assuming a 30% albedo -- 1.5 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 309139, (2017/12/17 06:40UT)
Object            RA         Dec     mag  sep  mel
Adhara         06:59:19.9 -28:59:51  1.5 26.66 124
15Rho Pup      08:08:18.6 -24:21:25  2.8 11.64 117
9 Hya          08:42:33.4 -16:00:32  4.6  1.56 115
PPM 220363     08:37:42.6 -14:49:59  8.4  0.15 116
309139         08:37:39.1 -14:59:09 14.8       116
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.

Event circumstances last updated at 2016/03/21 17:23:34 UT

Marc W. Buie, Southwest Research Institute

RECON