RECON: TNO occultation with 55638

Event between (55638) 02VE95 and star UC4-489-015461 with event index number of 101227

Geocentric closest approach at 2018/01/03 20:57:44 UTC

J2000 position of star is 05:54:37.8 +07:36:18
Equinox of date position of star is 05:55:34.3 +07:36:26
Stellar brightness R=15.5, use SENSEUP=128
Star is 42 degrees from the moon. Moon is 95% illuminated.
TNO apparent brightness V=20.3

TNO is 29.8 AU from the Sun and 28.8 AU from the Earth.
The TNO is moving 23.4 km/sec on the sky relative to the star, or, 4.0 arcsec/hr.
The 1-sigma error in the time of the event is 74 seconds.
The 1-sigma cross-track error in the shadow position is 1058 km.

The TNO has an absolute magnitude Hv=5.5
Diameter=478.6 km assuming a 5% albedo -- 20.5 sec chord
Diameter=195.4 km assuming a 30% albedo -- 8.4 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 55638, (2018/01/03 20:58UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:08.8 +07:24:32  0.4  0.24  42
Bellatrix      05:26:05.9 +06:21:52  1.6  7.43  50
PPM 149639     05:55:53.2 +05:51:46  6.4  1.75  43
PPM 149657     05:57:03.9 +07:50:52  8.5  0.43  42
PPM 149617     05:55:02.2 +07:42:56  9.5  0.18  42
55638          05:55:36.4 +07:36:26 15.5        42
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.

Do not use the listing below for the RECON CPC 1100 telescopes. This is provided for other non-team facilities.

Star training set for 55638, (2018/01/03 20:58UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:55:10.3 +07:24:26  0.4  0.24  42
Bellatrix      05:25:07.8 +06:20:58  1.6  7.43  50
PPM 149639     05:54:55.4 +05:51:39  6.4  1.75  43
PPM 149657     05:56:05.2 +07:50:46  8.5  0.43  42
PPM 149617     05:54:03.6 +07:42:48  9.5  0.18  42
55638          05:54:37.8 +07:36:18 15.5        42
Positions are for J2000

Event circumstances last updated at 2017/05/17 17:58:51 UT

Marc W. Buie, Southwest Research Institute

RECON