RECON: TNO occultation with 531075

Event between (531075) 12DY98 and star GA0780:04348649 with event index number of 2444698

Geocentric closest approach at 2025/05/14 14:30:22 UTC

J2000 position of star is 13:13:40.9 -10:02:27
Equinox of date position of star is 13:14:57.9 -10:10:11
Stellar brightness G=16.5, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 54 degrees from the moon. Moon is 97% illuminated.
Apparent brightness V=23.0

Object is 36.3 AU from the Sun and 35.5 AU from the Earth.
Apparent velocity is 19.3 km/sec on the sky relative to the star, or, 2.7 arcsec/hr.
The 1-sigma error in the time of the event is 135 seconds.
The 1-sigma cross-track error in the shadow position is 2447 km.

The object has an absolute magnitude Hv=7.3
Diameter=218.8 km assuming a 5% albedo -- 11.0 sec chord
Diameter=89.3 km assuming a 30% albedo -- 4.5 sec chord
Dynamical classification is SCATNEAR
 
 
 
 
 
 
 
 

Star training set for 531075, (2025/05/14 14:31UT)
Object            RA         Dec     mag  sep  mel
Spica          13:26:32.0 -11:17:34  1.0  3.04  51
50 Vir         13:11:05.1 -10:27:50  5.8  1.01  55
PPM 226902     13:12:10.0 -10:14:15  8.2  0.70  55
PPM 226942     13:13:42.3 -10:15:14  9.6  0.33  54
531075         13:15:00.8 -10:10:29 16.5        54
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 531075, (2025/05/14 14:31UT)
Object            RA         Dec     mag  sep  mel
Spica          13:25:11.5 -11:09:41  1.0  3.04  51
50 Vir         13:09:45.3 -10:19:46  5.8  1.01  55
PPM 226902     13:10:50.2 -10:06:11  8.2  0.70  55
PPM 226942     13:12:22.4 -10:07:11  9.6  0.33  54
531075         13:13:40.9 -10:02:27 16.5        54
Positions are for J2000

Event circumstances last updated at 2024/06/13 03:46:45 UT

Marc W. Buie, Southwest Research Institute

RECON