RECON: TNO occultation with 29981

Event between (29981) 99TD10 and star UC4-537-028973 with event index number of 67905

Geocentric closest approach at 2017/03/24 15:40:17 UTC

J2000 position of star is 06:32:23.5 +17:16:03
Equinox of date position of star is 06:33:20.1 +17:15:16
Stellar brightness R=11.4
Star is 138 degrees from the moon. Moon is 14% illuminated.
TNO apparent brightness V=23.4

TNO is 28.4 AU from the Sun and 28.3 AU from the Earth.
The TNO is moving 4.1 km/sec on the sky relative to the star, or, 0.7 arcsec/hr.
The 1-sigma error in the time of the event is 1435 seconds.
The 1-sigma cross-track error in the shadow position is 2238 km.

The TNO has an absolute magnitude Hv=8.7
Diameter=109.7 km assuming a 5% albedo -- 26.5 sec chord
Diameter=44.8 km assuming a 30% albedo -- 10.8 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 29981, (2017/03/24 15:40UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:06.3 +07:24:32  0.4 13.40 128
Alhena         06:38:42.4 +16:22:59  1.9  1.54 139
PPM 122879     06:42:21.5 +16:22:48  5.9  2.32 140
PPM 122609     06:32:41.8 +17:04:07  8.5  0.25 138
PPM 122656     06:34:14.0 +17:18:17 10.5  0.21 138
29981          06:33:23.6 +17:15:13 11.4       138
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 2016/03/20 17:19:52 UT

Marc W. Buie, Southwest Research Institute

RECON