RECON: TNO occultation with 525815

Event between (525815) 05SD278 and star GA0940:00488851 with event index number of 2116809

Geocentric closest approach at 2026/01/08 21:58:33 UTC

J2000 position of star is 04:46:04.6 +04:14:34
Equinox of date position of star is 04:47:20.3 +04:17:04
Stellar brightness G=15.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 107 degrees from the moon. Moon is 67% illuminated.
Apparent brightness V=22.9

Object is 44.8 AU from the Sun and 44.1 AU from the Earth.
Apparent velocity is 20.1 km/sec on the sky relative to the star, or, 2.3 arcsec/hr.
The 1-sigma error in the time of the event is 186 seconds.
The 1-sigma cross-track error in the shadow position is 1724 km.

The object has an absolute magnitude Hv=6.3
Diameter=346.7 km assuming a 5% albedo -- 16.5 sec chord
Diameter=141.6 km assuming a 30% albedo -- 6.8 sec chord
Dynamical classification is SCATNEAR
 
 
 
 
 
 
 
 

Star training set for 525815, (2026/01/08 21:58UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:25.0 +16:33:35  0.8 12.52 109
Bellatrix      05:26:31.7 +06:22:16  1.6  9.95  97
PPM 147967     04:48:41.3 +05:49:59  6.4  1.58 107
PPM 147931     04:47:18.8 +04:24:20  8.0  0.12 107
525815         04:47:27.1 +04:17:18 15.9       106
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 525815, (2026/01/08 21:58UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 12.52 109
Bellatrix      05:25:07.8 +06:20:58  1.6  9.95  97
PPM 147967     04:47:17.9 +05:47:17  6.4  1.58 107
PPM 147931     04:45:56.2 +04:21:36  8.0  0.12 107
525815         04:46:04.6 +04:14:34 15.9       107
Positions are for J2000

Event circumstances last updated at 2023/11/16 03:52:21 UT

Marc W. Buie, Southwest Research Institute

RECON