RECON: TNO occultation with 60558

Event between (60558) Echeclus and star UC4-510-004030 with event index number of 106252

Geocentric closest approach at 2018/02/13 17:40:52 UTC

J2000 position of star is 02:41:09.5 +11:58:20
Equinox of date position of star is 02:42:06.8 +12:02:48
Stellar brightness R=15.7, use SENSEUP=128
Star is 100 degrees from the moon. Moon is 4% illuminated.
TNO apparent brightness V=18.8

TNO is 7.5 AU from the Sun and 7.6 AU from the Earth.
The TNO is moving 18.6 km/sec on the sky relative to the star, or, 12.1 arcsec/hr.
The 1-sigma error in the time of the event is 16 seconds.
The 1-sigma cross-track error in the shadow position is 280 km.

The TNO has an absolute magnitude Hv=9.5
Diameter=72.4 km assuming a 5% albedo -- 4.1 sec chord
Diameter=29.6 km assuming a 30% albedo -- 1.7 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 
 
 

Star training set for 60558, (2018/02/13 17:41UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:36:57.7 +16:32:40  0.8 28.15 128
Menkar         03:03:13.7 +04:09:35  2.5  9.46 103
38 Ari         02:45:57.0 +12:31:15  5.4  1.04 101
PPM 118397     02:38:44.4 +12:20:50  8.2  0.88 100
PPM 118439     02:41:42.2 +11:35:28  9.0  0.47 100
PPM 118422     02:40:57.6 +11:49:51 10.9  0.36 100
60558          02:42:08.6 +12:02:57 15.7       101
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, (2018/02/13 17:41UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:30  0.8 28.15 128
Menkar         03:02:16.8 +04:05:22  2.5  9.46 103
38 Ari         02:44:57.7 +12:26:43  5.4  1.04 101
PPM 118397     02:37:45.3 +12:16:10  8.2  0.88 100
PPM 118439     02:40:43.3 +11:30:51  9.0  0.47 100
PPM 118422     02:39:58.7 +11:45:14 10.9  0.36 100
60558          02:41:09.5 +11:58:20 15.7       100
Positions are for J2000

Event circumstances last updated at 2017/07/31 16:27:17 UT

Marc W. Buie, Southwest Research Institute

RECON