RECON: TNO occultation with 55638

Event between (55638) 02VE95 and star UC4-490-017486 with event index number of 188104

Geocentric closest approach at 2019/04/10 00:02:55 UTC

J2000 position of star is 06:01:29.9 +07:59:19
Equinox of date position of star is 06:02:28.4 +07:59:16
Stellar brightness R=16.1, use SENSEUP=128
Star is 20 degrees from the moon. Moon is 21% illuminated.
TNO apparent brightness V=20.5

TNO is 30.0 AU from the Sun and 30.3 AU from the Earth.
The TNO is moving 16.8 km/sec on the sky relative to the star, or, 2.7 arcsec/hr.
The 1-sigma error in the time of the event is 121 seconds.
The 1-sigma cross-track error in the shadow position is 1568 km.

The TNO has an absolute magnitude Hv=5.5
Diameter=478.6 km assuming a 5% albedo -- 28.5 sec chord
Diameter=195.4 km assuming a 30% albedo -- 11.6 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 55638, (2019/04/10 00:03UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:12.9 +07:24:33  0.4  1.67  19
Bellatrix      05:26:09.9 +06:21:56  1.6  9.17  15
PPM 149639     05:55:57.3 +05:51:47  6.4  2.68  20
PPM 149761     06:01:45.3 +08:17:37  8.4  0.36  19
PPM 149814     06:03:44.4 +08:00:59  8.7  0.30  20
PPM 149780     06:02:24.4 +07:51:12 10.1  0.14  20
55638          06:02:32.8 +07:59:16 16.1        20
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, (2019/04/10 00:03UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:55:10.3 +07:24:26  0.4  1.67  19
Bellatrix      05:25:07.8 +06:20:58  1.6  9.17  15
PPM 149639     05:54:55.4 +05:51:39  6.4  2.68  20
PPM 149761     06:00:42.3 +08:17:39  8.4  0.36  19
PPM 149814     06:02:41.5 +08:01:04  8.7  0.30  20
PPM 149780     06:01:21.6 +07:51:15 10.1  0.14  20
55638          06:01:29.9 +07:59:19 16.1        20
Positions are for J2000

Event circumstances last updated at 2017/12/06 18:50:45 UT

Marc W. Buie, Southwest Research Institute

RECON