RECON: TNO occultation with 28978

Event between (28978) Ixion and star UC4-308-135754 with event index number of 109924

Geocentric closest approach at 2018/03/16 20:29:30 UTC

J2000 position of star is 17:47:16.7 -28:35:04
Equinox of date position of star is 17:48:18.5 -28:35:21
Stellar brightness R=16.1
Star is 81 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=19.7

TNO is 39.5 AU from the Sun and 39.5 AU from the Earth.
The TNO is moving 6.9 km/sec on the sky relative to the star, or, 0.9 arcsec/hr.
The 1-sigma error in the time of the event is 438 seconds.
The 1-sigma cross-track error in the shadow position is 3843 km.

The TNO has an absolute magnitude Hv=3.6
Diameter=1148.2 km assuming a 5% albedo -- 165.8 sec chord
Diameter=468.7 km assuming a 30% albedo -- 67.7 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 28978, (2018/03/16 20:30UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:31.6 -26:28:15  0.9 17.38  98
34Ups Sco      17:32:00.2 -37:18:31  2.7  9.37  83
3 Sgr          17:48:42.4 -27:50:10  4.2  0.76  81
PPM 267324     17:49:21.6 -28:46:04  8.5  0.27  80
28978          17:48:25.9 -28:35:23 16.1        80
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 2016/04/02 16:40:46 UT

Marc W. Buie, Southwest Research Institute

RECON