RECON: TNO occultation with 181708

Event between (181708) 93FW and star GA0760:05212925 with event index number of 2559354

Geocentric closest approach at 2026/07/24 07:39:41 UTC

J2000 position of star is 15:21:01.9 -12:44:27
Equinox of date position of star is 15:22:22.7 -12:49:39
Stellar brightness G=16.8, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 16 degrees from the moon. Moon is 76% illuminated.
Apparent brightness V=23.2

Object is 41.6 AU from the Sun and 41.3 AU from the Earth.
Apparent velocity is 5.7 km/sec on the sky relative to the star, or, 0.7 arcsec/hr.
The 1-sigma error in the time of the event is 912 seconds.
The 1-sigma cross-track error in the shadow position is 1701 km.

The object has an absolute magnitude Hv=6.9
Diameter=252.4 km assuming a 5% albedo -- 44.7 sec chord
Diameter=103.0 km assuming a 30% albedo -- 18.3 sec chord
Dynamical classification is CLASSICAL
 
 
 
 
 
 
 
 

Star training set for 181708, (2026/07/24 07:40UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:02.4 -26:29:19  0.9 21.09   7
27Bet Lib      15:18:26.4 -09:28:45  2.6  3.50  19
31Eps Lib      15:25:38.5 -10:24:57  4.8  2.54  18
PPM 230086     15:21:37.5 -13:17:11  8.3  0.50  16
PPM 230119     15:22:48.5 -12:49:06  9.7  0.08  16
181708         15:22:29.7 -12:50:06 16.8        16
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 181708, (2026/07/24 07:40UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 21.09   7
27Bet Lib      15:17:00.3 -09:22:59  2.6  3.50  19
31Eps Lib      15:24:11.8 -10:19:23  4.8  2.54  18
PPM 230086     15:20:09.4 -13:11:30  8.3  0.50  16
PPM 230119     15:21:20.6 -12:43:28  9.7  0.08  16
181708         15:21:01.9 -12:44:27 16.8        16
Positions are for J2000

Event circumstances last updated at 2024/06/10 01:52:52 UT

Marc W. Buie, Southwest Research Institute

RECON