RECON: TNO occultation with 181855

Event between (181855) 98WT31 and star GA1320:02720498 with event index number of 1211402

Geocentric closest approach at 2022/12/23 22:03:22 UTC

J2000 position of star is 05:11:07.2 +42:36:18
Equinox of date position of star is 05:12:44.5 +42:37:53
Stellar brightness G=15.7, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 156 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=23.5

TNO is 37.6 AU from the Sun and 36.7 AU from the Earth.
The TNO is moving 24.8 km/sec on the sky relative to the star, or, 3.4 arcsec/hr.
The 1-sigma error in the time of the event is 236 seconds.
The 1-sigma cross-track error in the shadow position is 3292 km.

The TNO has an absolute magnitude Hv=7.7
Diameter=173.8 km assuming a 5% albedo -- 7.0 sec chord
Diameter=70.9 km assuming a 30% albedo -- 2.9 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 
 
 

Star training set for 181855, (2022/12/23 22:03UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:14.5 +16:33:13  0.8 27.16 149
34Bet Aur      06:01:12.9 +44:56:50  1.9  9.04 161
PPM 047726     05:08:28.2 +43:12:13  6.5  0.97 155
PPM 047811     05:13:07.1 +42:46:29  8.1  0.16 156
181855         05:12:45.5 +42:37:54 15.7       157
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 181855, (2022/12/23 22:03UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 27.16 149
34Bet Aur      05:59:31.6 +44:56:51  1.9  9.04 161
PPM 047726     05:06:49.5 +43:10:29  6.5  0.97 155
PPM 047811     05:11:28.7 +42:44:54  8.1  0.16 156
181855         05:11:07.2 +42:36:18 15.7       156
Positions are for J2000

Event circumstances last updated at 2022/09/30 04:14:25 UT

Marc W. Buie, Southwest Research Institute

RECON