RECON: TNO occultation with 60558

Event between (60558) Echeclus and star GA1080:02191650 with event index number of 2336841

Geocentric closest approach at 2021/12/17 17:16:19 UTC

J2000 position of star is 06:35:44.9 +18:33:54
Equinox of date position of star is 06:37:01.9 +18:32:45
Stellar brightness G=15.8, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 29 degrees from the moon. Moon is 98% illuminated.
TNO apparent brightness V=19.6

TNO is 11.1 AU from the Sun and 10.1 AU from the Earth.
The TNO is moving 21.8 km/sec on the sky relative to the star, or, 10.7 arcsec/hr.
The 1-sigma error in the time of the event is 18 seconds.
The 1-sigma cross-track error in the shadow position is 368 km.

The TNO has an absolute magnitude Hv=9.2
Diameter=88.3 km assuming a 5% albedo -- 4.1 sec chord
Diameter=36.1 km assuming a 30% albedo -- 1.7 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 60558, (2021/12/17 17:16UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:21.7 +07:24:34  0.4 14.89  25
Alhena         06:38:58.8 +16:22:43  1.9  2.22  30
26 Gem         06:43:41.0 +17:37:19  5.3  1.83  31
PPM 122704     06:36:02.9 +18:19:58  8.4  0.32  29
PPM 122752     06:37:32.2 +18:22:24 10.9  0.21  29
60558          06:37:02.2 +18:32:44 15.8        29
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 60558, (2021/12/17 17:16UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:55:10.3 +07:24:26  0.4 14.89  25
Alhena         06:37:42.8 +16:23:57  1.9  2.22  30
26 Gem         06:42:24.3 +17:38:42  5.3  1.83  31
PPM 122704     06:34:45.8 +18:21:06  8.4  0.32  29
PPM 122752     06:36:15.1 +18:23:35 10.9  0.21  29
60558          06:35:44.9 +18:33:54 15.8        29
Positions are for J2000

Event circumstances last updated at 2021/11/15 00:44:45 UT

Marc W. Buie, Southwest Research Institute

RECON