RECON: TNO occultation with 342842

Event between (342842) 08YB3 and star GA1180:09337920 with event index number of 2204429

Geocentric closest approach at 2025/09/28 19:16:08 UTC

J2000 position of star is 19:41:46.7 +29:16:39
Equinox of date position of star is 19:42:44.7 +29:20:08
Stellar brightness G=14.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 66 degrees from the moon. Moon is 39% illuminated.
Apparent brightness V=21.8

Object is 15.9 AU from the Sun and 15.5 AU from the Earth.
Apparent velocity is 30.0 km/sec on the sky relative to the star, or, 9.6 arcsec/hr.
The 1-sigma error in the time of the event is 57 seconds.
The 1-sigma cross-track error in the shadow position is 793 km.

The object has an absolute magnitude Hv=9.5
Diameter=82.8 km assuming a 5% albedo -- 2.6 sec chord
Diameter=33.8 km assuming a 30% albedo -- 1.1 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 342842, (2025/09/28 19:19UT)
Object            RA         Dec     mag  sep  mel
Vega           18:37:48.6 +38:48:31  0.0 16.42  69
37Gam Cyg      20:23:09.2 +40:20:25  2.2 13.75  80
PPM 109352     19:38:11.2 +29:23:35  6.1  1.01  66
PPM 109509     19:42:21.7 +29:12:22  8.5  0.16  66
342842         19:42:48.5 +29:20:21 14.9        66
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 342842, (2025/09/28 19:19UT)
Object            RA         Dec     mag  sep  mel
Vega           18:36:56.7 +38:47:07  0.0 16.42  69
37Gam Cyg      20:22:13.7 +40:15:24  2.2 13.75  80
PPM 109352     19:37:09.6 +29:20:02  6.1  1.01  66
PPM 109509     19:41:19.9 +29:08:40  8.5  0.16  66
342842         19:41:46.7 +29:16:39 14.9        66
Positions are for J2000

Event circumstances last updated at 2024/03/03 05:55:14 UT

Marc W. Buie, Southwest Research Institute

RECON