RECON: TNO occultation with 15810

Event between (15810) Arawn and star GA0700:33943178 with event index number of 1497623

Geocentric closest approach at 2025/08/20 22:23:28 UTC

J2000 position of star is 20:04:48.2 -18:41:11
Equinox of date position of star is 20:06:10.1 -18:37:04
Stellar brightness G=14.3, use SENSEUP=64 with the MallinCam and and exposure time of 1 seconds with the QHY174 camera.
Star is 174 degrees from the moon. Moon is 6% illuminated.
Apparent brightness V=23.3

Object is 36.3 AU from the Sun and 35.4 AU from the Earth.
Apparent velocity is 20.7 km/sec on the sky relative to the star, or, 2.9 arcsec/hr.
The 1-sigma error in the time of the event is 364 seconds.
The 1-sigma cross-track error in the shadow position is 1946 km.

The object has an absolute magnitude Hv=7.7
Diameter=173.8 km assuming a 5% albedo -- 8.5 sec chord
Diameter=70.9 km assuming a 30% albedo -- 3.5 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 
 
 

Star training set for 15810, (2025/08/20 22:30UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:59:03.6 -29:29:08  1.2 40.67 143
Nunki          18:56:51.2 -26:15:45  2.0 17.75 163
57 Sgr         19:53:41.2 -18:58:40  5.8  3.00 173
PPM 236935     20:07:31.4 -18:37:46  8.3  0.29 175
PPM 236877     20:05:20.7 -18:42:53  9.1  0.24 174
15810          20:06:16.9 -18:36:43 14.3       174
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 15810, (2025/08/20 22:30UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:57:39.6 -29:37:24  1.2 40.67 143
Nunki          18:55:15.9 -26:17:49  2.0 17.75 163
57 Sgr         19:52:12.0 -19:02:43  5.8  3.00 173
PPM 236935     20:06:02.7 -18:42:16  8.3  0.29 175
PPM 236877     20:03:52.0 -18:47:19  9.1  0.24 174
15810          20:04:48.2 -18:41:11 14.3       174
Positions are for J2000

Event circumstances last updated at 2023/09/03 03:23:38 UT

Marc W. Buie, Southwest Research Institute

RECON