RECON: TNO occultation with 98WY31

Event between 98WY31 and star GA1140:02506421 with event index number of 1034701

Geocentric closest approach at 2021/01/13 19:04:20 UTC

J2000 position of star is 06:46:06.8 +24:14:31
Equinox of date position of star is 06:47:23.7 +24:13:06
Stellar brightness G=16.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 159 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=23.1

TNO is 42.9 AU from the Sun and 41.9 AU from the Earth.
The TNO is moving 24.9 km/sec on the sky relative to the star, or, 2.9 arcsec/hr.
The 1-sigma error in the time of the event is 61 seconds.
The 1-sigma cross-track error in the shadow position is 1520 km.

The TNO has an absolute magnitude Hv=6.8
Diameter=257.0 km assuming a 5% albedo -- 10.3 sec chord
Diameter=104.9 km assuming a 30% albedo -- 4.2 sec chord
Dynamical classification is CLASSICAL
 
 
 
 
 
 
 
 

Star training set for 98WY31, (2021/01/13 19:04UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:46:36.0 +27:58:25  1.1 13.80 171
Alhena         06:38:55.6 +16:22:46  1.9  8.09 156
PPM 096264     06:38:44.6 +24:34:17  6.5  2.00 157
PPM 096508     06:47:26.9 +23:20:52  7.4  0.87 159
PPM 096499     06:46:54.0 +24:06:11  8.7  0.16 159
98WY31         06:47:23.9 +24:13:05 16.9       159
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 98WY31, (2021/01/13 19:04UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:45:18.0 +28:01:33  1.1 13.80 171
Alhena         06:37:42.8 +16:23:57  1.9  8.09 156
PPM 096264     06:37:27.2 +24:35:27  6.5  2.00 157
PPM 096508     06:46:10.3 +23:22:18  7.4  0.87 159
PPM 096499     06:45:37.0 +24:07:36  8.7  0.16 159
98WY31         06:46:06.8 +24:14:31 16.9       159
Positions are for J2000

Event circumstances last updated at 2020/12/24 00:15:15 UT

Marc W. Buie, Southwest Research Institute

RECON