RECON: TNO occultation with 309139

Event between (309139) 06XQ51 and star UC4-377-049498 with event index number of 105654

Geocentric closest approach at 2018/02/25 16:28:46 UTC

J2000 position of star is 08:24:29.4 -14:36:58
Equinox of date position of star is 08:25:14.7 -14:40:10
Stellar brightness R=14.3
Star is 44 degrees from the moon. Moon is 76% illuminated.
TNO apparent brightness V=22.4

TNO is 17.6 AU from the Sun and 16.9 AU from the Earth.
The TNO is moving 22.2 km/sec on the sky relative to the star, or, 6.5 arcsec/hr.
The 1-sigma error in the time of the event is 265 seconds.
The 1-sigma cross-track error in the shadow position is 3876 km.

The TNO has an absolute magnitude Hv=9.8
Diameter=66.1 km assuming a 5% albedo -- 3.0 sec chord
Diameter=27.0 km assuming a 30% albedo -- 1.2 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 309139, (2018/02/25 16:29UT)
Object            RA         Dec     mag  sep  mel
Sirius         06:45:56.9 -16:44:29 -1.5 23.99  37
15Rho Pup      08:08:19.1 -24:21:27  2.8 10.48  50
PPM 220100     08:26:46.2 -14:59:23  6.0  0.47  44
PPM 220074     08:25:31.4 -14:39:41  8.4  0.05  44
309139         08:25:20.1 -14:40:33 14.3        44
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 2016/03/22 17:05:32 UT

Marc W. Buie, Southwest Research Institute

RECON