RECON: TNO occultation with 469987

Event between (469987) 06HJ123 and star GA0740:06802238 with event index number of 2256393

Geocentric closest approach at 2025/07/21 18:15:35 UTC

J2000 position of star is 17:05:30.7 -15:20:39
Equinox of date position of star is 17:06:51.0 -15:22:29
Stellar brightness G=14.8, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 167 degrees from the moon. Moon is 12% illuminated.
Apparent brightness V=21.2

Object is 31.9 AU from the Sun and 31.2 AU from the Earth.
Apparent velocity is 16.3 km/sec on the sky relative to the star, or, 2.6 arcsec/hr.
The 1-sigma error in the time of the event is 90 seconds.
The 1-sigma cross-track error in the shadow position is 1144 km.

The object has an absolute magnitude Hv=6.1
Diameter=359.8 km assuming a 5% albedo -- 22.2 sec chord
Diameter=146.9 km assuming a 30% albedo -- 9.1 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 469987, (2025/07/21 18:17UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:58.7 -26:29:11  0.9 13.92 171
35Eta Oph      17:11:50.7 -15:45:17  2.6  1.23 168
PPM 232651     17:09:44.0 -17:38:26  6.0  2.36 170
PPM 232639     17:09:14.0 -16:07:29  6.9  0.92 168
PPM 232582     17:06:27.1 -15:22:26  9.2  0.13 167
469987         17:06:58.4 -15:22:39 14.8       167
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 469987, (2025/07/21 18:17UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 13.92 171
35Eta Oph      17:10:22.7 -15:43:29  2.6  1.23 168
PPM 232651     17:08:14.9 -17:36:33  6.0  2.36 170
PPM 232639     17:07:45.8 -16:05:35  6.9  0.92 168
PPM 232582     17:04:59.4 -15:20:26  9.2  0.13 167
469987         17:05:30.7 -15:20:39 14.8       167
Positions are for J2000

Event circumstances last updated at 2023/05/28 03:52:09 UT

Marc W. Buie, Southwest Research Institute

RECON