RECON: TNO occultation with 04HX78

Event between 04HX78 and star UC4-378-084698 with event index number of 113338

Geocentric closest approach at 2018/04/18 20:51:43 UTC

J2000 position of star is 17:21:51.9 -14:35:09
Equinox of date position of star is 17:22:47.7 -14:36:03
Stellar brightness R=15.3
Star is 164 degrees from the moon. Moon is 10% illuminated.
TNO apparent brightness V=23.5

TNO is 33.5 AU from the Sun and 32.9 AU from the Earth.
The TNO is moving 13.4 km/sec on the sky relative to the star, or, 2.0 arcsec/hr.
The 1-sigma error in the time of the event is 1016 seconds.
The 1-sigma cross-track error in the shadow position is 3378 km.

The TNO has an absolute magnitude Hv=8.1
Diameter=143.9 km assuming a 5% albedo -- 10.8 sec chord
Diameter=58.7 km assuming a 30% albedo -- 4.4 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 04HX78, (2018/04/18 20:52UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:31.9 -26:28:16  0.9 17.04 170
35Eta Oph      17:11:25.7 -15:44:47  2.6  3.00 167
PPM 232829     17:16:22.8 -14:36:13  5.9  1.58 166
PPM 232909     17:20:00.8 -15:14:19  8.1  0.95 165
PPM 232982     17:23:02.5 -14:19:51  9.3  0.27 164
04HX78         17:22:54.4 -14:36:09 15.3       164
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 2016/05/01 17:08:28 UT

Marc W. Buie, Southwest Research Institute

RECON