RECON: TNO occultation with 525816

Event between (525816) 05SF278 and star GA1040:00549551 with event index number of 2167460

Geocentric closest approach at 2028/01/25 23:01:26 UTC

J2000 position of star is 04:39:40.4 +15:15:31
Equinox of date position of star is 04:40:59.3 +15:18:09
Stellar brightness G=15.5, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 132 degrees from the moon. Moon is 0% illuminated.
Apparent brightness V=22.3

Object is 35.6 AU from the Sun and 35.0 AU from the Earth.
Apparent velocity is 13.0 km/sec on the sky relative to the star, or, 1.8 arcsec/hr.
The 1-sigma error in the time of the event is 181 seconds.
The 1-sigma cross-track error in the shadow position is 1450 km.

The object has an absolute magnitude Hv=6.7
Diameter=279.3 km assuming a 5% albedo -- 21.0 sec chord
Diameter=114.0 km assuming a 30% albedo -- 8.6 sec chord
Dynamical classification is 7:4EEE
 
 
 
 
 
 
 
 

Star training set for 525816, (2028/01/25 23:09UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:32.1 +16:33:49  0.8  1.54 131
Bellatrix      05:26:38.3 +06:22:22  1.6 14.27 139
91Sig1Tau      04:40:45.5 +15:51:11  5.3  0.56 132
PPM 120087     04:39:08.0 +15:12:02  8.0  0.53 131
PPM 120103     04:40:34.5 +15:37:27  9.8  0.35 132
525816         04:41:16.3 +15:18:42 15.5       132
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 525816, (2028/01/25 23:09UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8  1.54 131
Bellatrix      05:25:07.8 +06:20:58  1.6 14.27 139
91Sig1Tau      04:39:09.2 +15:47:58  5.3  0.56 132
PPM 120087     04:37:32.1 +15:08:46  8.0  0.53 131
PPM 120103     04:38:58.3 +15:34:15  9.8  0.35 132
525816         04:39:40.4 +15:15:31 15.5       132
Positions are for J2000

Event circumstances last updated at 2023/02/06 03:27:20 UT

Marc W. Buie, Southwest Research Institute

RECON