RECON: TNO occultation with 55576

Event between (55576) Amycus and star GA0640:38330844 with event index number of 2572865

Geocentric closest approach at 2022/04/19 21:13:30 UTC

J2000 position of star is 20:06:37.9 -24:53:53
Equinox of date position of star is 20:07:56.3 -24:50:03
Stellar brightness G=14.4, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 47 degrees from the moon. Moon is 87% illuminated.
TNO apparent brightness V=21.0

TNO is 22.9 AU from the Sun and 22.8 AU from the Earth.
The TNO is moving 5.8 km/sec on the sky relative to the star, or, 1.3 arcsec/hr.
The 1-sigma error in the time of the event is 336 seconds.
The 1-sigma cross-track error in the shadow position is 1190 km.

The TNO has an absolute magnitude Hv=7.2
Diameter=227.0 km assuming a 5% albedo -- 37.7 sec chord
Diameter=92.7 km assuming a 30% albedo -- 15.4 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 55576, (2022/04/19 21:14UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:58:52.7 -29:30:13  1.2 38.09  82
38Zet Sgr      19:04:01.7 -29:50:47  2.7 15.04  33
60 Sgr         20:00:18.5 -26:08:01  4.5  2.16  45
PPM 270700     20:07:57.2 -25:30:40  8.5  0.68  47
PPM 270713     20:08:27.1 -24:42:30  9.4  0.17  47
55576          20:07:58.2 -24:49:58 14.4        47
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 55576, (2022/04/19 21:14UT)
Object            RA         Dec     mag  sep  mel
Fomalhaut      22:57:39.6 -29:37:24  1.2 38.09  82
38Zet Sgr      19:02:36.7 -29:52:49  2.7 15.04  33
60 Sgr         19:58:57.3 -26:11:44  4.5  2.16  45
PPM 270700     20:06:36.5 -25:34:36  8.5  0.68  47
PPM 270713     20:07:06.8 -24:46:26  9.4  0.17  47
55576          20:06:37.9 -24:53:53 14.4        47
Positions are for J2000

Event circumstances last updated at 2021/10/12 02:07:38 UT

Marc W. Buie, Southwest Research Institute

RECON