RECON: TNO occultation with 69990

Event between (69990) 98WU31 and star GA1080:02376920 with event index number of 1524610

Geocentric closest approach at 2025/09/19 16:36:56 UTC

J2000 position of star is 06:46:38.4 +18:34:28
Equinox of date position of star is 06:48:04.4 +18:32:47
Stellar brightness G=14.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 52 degrees from the moon. Moon is 5% illuminated.
Apparent brightness V=24.0

Object is 36.8 AU from the Sun and 37.0 AU from the Earth.
Apparent velocity is 12.2 km/sec on the sky relative to the star, or, 1.6 arcsec/hr.
The 1-sigma error in the time of the event is 1315 seconds.
The 1-sigma cross-track error in the shadow position is 4868 km.

The object has an absolute magnitude Hv=8.2
Diameter=144.5 km assuming a 5% albedo -- 11.4 sec chord
Diameter=59.0 km assuming a 30% albedo -- 4.7 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 69990, (2025/09/19 16:37UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:46:53.4 +27:57:43  1.1 16.43  39
Alhena         06:39:11.8 +16:22:30  1.9  3.04  54
PPM 123009     06:47:51.6 +18:48:31  6.5  0.27  52
PPM 122996     06:47:19.3 +18:40:59 10.0  0.24  52
69990          06:48:08.8 +18:32:42 14.9        51
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 69990, (2025/09/19 16:37UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:45:17.9 +28:01:33  1.1 16.43  39
Alhena         06:37:42.8 +16:23:57  1.9  3.04  54
PPM 123009     06:46:21.1 +18:50:16  6.5  0.27  52
PPM 122996     06:45:48.8 +18:42:43 10.0  0.24  52
69990          06:46:38.4 +18:34:28 14.9        51
Positions are for J2000

Event circumstances last updated at 2024/06/18 02:54:09 UT

Marc W. Buie, Southwest Research Institute

RECON