RECON: TNO occultation with 20YR3

Event between 20YR3 and star GA1220:02236817 with event index number of 2179048

Geocentric closest approach at 2021/11/24 15:54:05 UTC

J2000 position of star is 05:51:48.0 +32:25:50
Equinox of date position of star is 05:53:13.4 +32:26:04
Stellar brightness G=11.9, use SENSEUP=16 with the MallinCam and and exposure time of 250 milli-seconds with the QHY174 camera.
Star is 32 degrees from the moon. Moon is 77% illuminated.
TNO apparent brightness V=21.8

TNO is 17.5 AU from the Sun and 16.6 AU from the Earth.
The TNO is moving 36.8 km/sec on the sky relative to the star, or, 11.0 arcsec/hr.
The 1-sigma error in the time of the event is 28 seconds.
The 1-sigma cross-track error in the shadow position is 658 km.

The TNO has an absolute magnitude Hv=9.3
Diameter=85.1 km assuming a 5% albedo -- 2.3 sec chord
Diameter=34.7 km assuming a 30% albedo -- 0.9 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 20YR3, (2021/11/24 15:54UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:10.8 +16:33:06  0.8 23.41  51
Alnath         05:27:40.7 +28:37:26  1.6  6.69  37
PPM 071002     05:56:24.3 +31:42:10  5.9  0.99  31
PPM 070923     05:52:51.4 +32:07:44  7.8  0.32  32
PPM 070937     05:53:20.5 +32:14:37  9.1  0.19  32
PPM 070945     05:53:44.8 +32:33:23 10.9  0.16  32
20YR3          05:53:13.9 +32:26:04 11.9        31
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 20YR3, (2021/11/24 15:54UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8 23.41  51
Alnath         05:26:17.6 +28:36:23  1.6  6.69  37
PPM 071002     05:54:58.9 +31:42:02  5.9  0.99  31
PPM 070923     05:51:25.7 +32:07:29  7.8  0.32  32
PPM 070937     05:51:54.8 +32:14:22  9.1  0.19  32
PPM 070945     05:52:18.8 +32:33:10 10.9  0.16  32
20YR3          05:51:48.0 +32:25:50 11.9        32
Positions are for J2000

Event circumstances last updated at 2021/10/10 01:00:32 UT

Marc W. Buie, Southwest Research Institute

RECON