RECON: TNO occultation with 69987

Event between (69987) 98WA25 and star GA1120:01480192 with event index number of 1807866

Geocentric closest approach at 2028/01/09 19:42:21 UTC

J2000 position of star is 05:48:35.0 +22:36:43
Equinox of date position of star is 05:49:58.4 +22:37:04
Stellar brightness G=16.0, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 11 degrees from the moon. Moon is 92% illuminated.
Apparent brightness V=23.4

Object is 42.6 AU from the Sun and 41.7 AU from the Earth.
Apparent velocity is 23.7 km/sec on the sky relative to the star, or, 2.8 arcsec/hr.
The 1-sigma error in the time of the event is 473 seconds.
The 1-sigma cross-track error in the shadow position is 2309 km.

The object has an absolute magnitude Hv=7.1
Diameter=229.1 km assuming a 5% albedo -- 9.8 sec chord
Diameter=93.5 km assuming a 30% albedo -- 4.0 sec chord
Dynamical classification is CLASSICAL
 
 
 
 
 
 
 
 

Star training set for 69987, (2028/01/09 19:56UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:41.4 +07:24:36  0.4 15.29  23
Alnath         05:28:04.0 +28:37:43  1.6  7.82   6
PPM 094739     05:45:01.7 +23:12:54  5.9  1.35  10
PPM 094731     05:44:43.8 +22:41:12  8.5  1.28  10
PPM 094938     05:51:16.0 +22:44:28  9.7  0.26  11
PPM 094915     05:50:32.8 +22:29:27 10.7  0.14  11
69987          05:50:16.7 +22:37:08 16.0        12
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 69987, (2028/01/09 19:56UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:55:10.3 +07:24:26  0.4 15.29  23
Alnath         05:26:17.6 +28:36:23  1.6  7.82   6
PPM 094739     05:43:19.5 +23:12:15  5.9  1.35  10
PPM 094731     05:43:02.0 +22:40:32  8.5  1.28  10
PPM 094938     05:49:34.2 +22:44:04  9.7  0.26  11
PPM 094915     05:48:51.1 +22:29:02 10.7  0.14  11
69987          05:48:35.0 +22:36:43 16.0        11
Positions are for J2000

Event circumstances last updated at 2022/12/26 04:16:05 UT

Marc W. Buie, Southwest Research Institute

RECON