RECON: TNO occultation with 54598

Event between (54598) Bienor and star GA1240:03239738 with event index number of 1477821

Geocentric closest approach at 2025/11/19 11:06:28 UTC

J2000 position of star is 08:18:19.5 +35:03:24
Equinox of date position of star is 08:19:45.2 +34:59:09
Stellar brightness G=15.0, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 110 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=18.9

[RECON map]
TNO is 13.3 AU from the Sun and 12.8 AU from the Earth.
The TNO is moving 7.4 km/sec on the sky relative to the star, or, 2.9 arcsec/hr.
The 1-sigma error in the time of the event is 95 seconds.
The 1-sigma cross-track error in the shadow position is 670 km.
The sky-plane scale is 9291.7 km/arcsec.

The TNO has an absolute magnitude Hv=7.4
Diameter=187.1 km assuming a 5% albedo -- 26.3 sec chord
Diameter=76.4 km assuming a 30% albedo -- 10.7 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 

Star training set for 54598, (2025/11/19 11:07UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:46:54.0 +27:57:42  1.1  9.94 116
32 Lyn         08:35:01.0 +36:20:48  6.5  3.35 108
PPM 073603     08:21:11.1 +34:57:46  7.6  0.25 110
54598          08:19:59.0 +34:58:28 15.0       110
Positions are for equinox of date

This table contains the target star visibility for the RECON network. The observing range has been set to a maximum of 5.0 sigma about the mid-time.
The median site spacing is 16.1 km RECON observability=1.0 and success probability=15.3%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Sleaford 11:09:55 -30.5 Dark Down 72.7 168.1 Up 11:01:32 - 11:18:19 3135
Kamloops 11:11:21 -39.3 Dark Down 69.5 132.6 Up 11:02:57 - 11:19:44 2362
Kelowna 11:11:08 -39.1 Dark Down 70.4 132.6 Up 11:02:45 - 11:19:32 2327
Peachland 11:11:10 -39.3 Dark Down 70.4 131.8 Up 11:02:47 - 11:19:34 2304
Summerland 11:11:08 -39.3 Dark Down 70.5 131.6 Up 11:02:44 - 11:19:31 2295
Penticton 11:11:07 -39.2 Dark Down 70.6 131.7 Up 11:02:43 - 11:19:30 2293
Oliver 11:11:03 -39.3 Dark Down 70.8 130.9 Up 11:02:40 - 11:19:27 2262
Dunrhomin 11:07:51 -31.0 Dark Down 83.9 147.1 Up 10:59:27 - 11:16:14 2260
Anarchist Mountain Observatory 11:11:01 -39.3 Dark Down 71.0 130.9 Up 11:02:37 - 11:19:24 2255
CU-SBO 11:07:47 -31.1 Dark Down 84.1 145.0 Up 10:59:23 - 11:16:10 2234
Tonasket 11:10:58 -39.4 Dark Down 71.2 130.1 Up 11:02:35 - 11:19:22 2224
Okanogan 11:10:57 -39.6 Dark Down 71.3 129.0 Up 11:02:33 - 11:19:20 2188
Brewster 11:10:56 -39.8 Dark Down 71.4 127.9 Up 11:02:33 - 11:19:20 2154
Manson/Chelan 11:10:58 -40.1 Dark Down 71.3 126.7 Up 11:02:34 - 11:19:21 2119
Wenatchee 11:10:55 -40.4 Dark Down 71.5 125.3 Up 11:02:32 - 11:19:19 2069
Victoria 11:11:27 -41.9 Dark Down 69.3 122.5 Up 11:03:04 - 11:19:51 2039
Ellensburg 11:10:53 -40.6 Dark Down 71.6 123.8 Up 11:02:30 - 11:19:17 2022
PNWRO 11:10:32 -39.8 Dark Down 73.1 124.2 Up 11:02:09 - 11:18:56 2008
Yakima 11:10:49 -40.7 Dark Down 71.8 122.7 Up 11:02:26 - 11:19:13 1984
Toppenish/White Swan 11:10:46 -40.7 Dark Down 72.0 122.4 Up 11:02:23 - 11:19:10 1972
Goldendale 11:10:46 -41.1 Dark Down 72.1 120.2 Up 11:02:23 - 11:19:10 1903
The Dalles 11:10:45 -41.4 Dark Down 72.0 118.9 Up 11:02:21 - 11:19:08 1866
Maupin 11:10:43 -41.5 Dark Down 72.2 118.0 Up 11:02:19 - 11:19:06 1833
Sisters 11:10:39 -42.1 Dark Down 72.3 114.6 Up 11:02:15 - 11:19:02 1731
Bend 11:10:36 -41.9 Dark Down 72.5 114.4 Up 11:02:12 - 11:18:59 1721
Oregon Observatory 11:10:34 -42.1 Dark Down 72.5 113.6 Up 11:02:11 - 11:18:58 1699
North Lake 11:10:24 -41.9 Dark Down 73.1 112.5 Up 11:02:00 - 11:18:47 1666
Lakeview 11:10:11 -41.7 Dark Down 73.8 110.0 Up 11:01:48 - 11:18:35 1597
Chiloquin 11:10:27 -42.7 Dark Down 72.7 109.0 Up 11:02:04 - 11:18:51 1560
Cedarville 11:10:04 -41.8 Dark Down 74.1 108.1 Up 11:01:41 - 11:18:28 1546
Klamath Falls 11:10:24 -42.7 Dark Down 72.8 108.1 Up 11:02:00 - 11:18:47 1532
Fall River/Burney 11:10:10 -42.7 Dark Down 73.4 104.8 Up 11:01:47 - 11:18:34 1444
Susanville 11:09:59 -42.4 Dark Down 74.1 103.6 Up 11:01:35 - 11:18:22 1423
Tonopah 11:09:08 -40.2 Dark Down 77.0 98.5 Up 11:00:45 - 11:17:32 1390
Gimple 11:09:58 -42.6 Dark Down 74.0 102.4 Up 11:01:35 - 11:18:22 1387
Reno 11:09:44 -41.9 Dark Down 74.9 101.5 Up 11:01:20 - 11:18:07 1386
Greenville 11:09:59 -42.6 Dark Down 73.9 102.3 Up 11:01:36 - 11:18:23 1383
Portola 11:09:52 -42.3 Dark Down 74.3 101.7 Up 11:01:28 - 11:18:15 1377
Yerington 11:09:33 -41.5 Dark Down 75.4 100.2 Up 11:01:10 - 11:17:57 1370
Quincy 11:09:59 -42.7 Dark Down 74.0 101.6 Up 11:01:36 - 11:18:23 1365
Hawthorne 11:09:26 -41.2 Dark Down 75.9 98.9 Up 11:01:02 - 11:17:49 1356
Carson City 11:09:40 -42.0 Dark Down 74.9 100.2 Up 11:01:17 - 11:18:04 1355
Patrick 11:08:14 -37.9 Dark Down 79.7 88.3 Up 10:59:51 - 11:16:38 1349
Indian Springs 11:08:41 -39.2 Dark Down 78.3 93.2 Up 11:00:18 - 11:17:05 1345
Henderson 11:08:30 -38.7 Dark Down 78.8 91.0 Up 11:00:07 - 11:16:54 1338
Gardnerville 11:09:40 -42.0 Dark Down 75.0 99.4 Up 11:01:16 - 11:18:03 1336
George/Scottsdale 11:07:41 -36.4 Dark Down 81.0 78.4 Up 10:59:17 - 11:16:04 1326
Kingman/Dolan Springs 11:08:14 -38.1 Dark Down 79.5 87.0 Up 10:59:50 - 11:16:37 1319
Beatty 11:08:54 -40.0 Dark Down 77.4 93.8 Up 11:00:31 - 11:17:18 1314
Laughlin/Bullhead City 11:08:18 -38.5 Dark Down 79.1 86.7 Up 10:59:55 - 11:16:42 1287
Lee Vining 11:09:24 -41.7 Dark Down 75.6 96.2 Up 11:01:01 - 11:17:48 1281
Bishop 11:09:12 -41.2 Dark Down 76.2 94.5 Up 11:00:48 - 11:17:35 1266
Mohave Valley 11:08:15 -38.5 Dark Down 79.1 85.3 Up 10:59:52 - 11:16:39 1264
Lake Havasu City 11:08:10 -38.3 Dark Down 79.2 83.3 Up 10:59:46 - 11:16:33 1245
Parker 11:08:06 -38.3 Dark Down 79.2 81.4 Up 10:59:43 - 11:16:30 1217
Yuma 11:07:56 -38.6 Dark Down 78.6 74.4 Up 10:59:32 - 11:16:19 1075
Calipatria 11:08:08 -39.3 Dark Down 78.0 76.8 Up 10:59:44 - 11:16:31 1059
Idyllwild 11:08:25 -40.3 Dark Down 77.2 79.7 Up 11:00:01 - 11:16:48 1043
Wildwood 11:08:47 -41.7 Dark Down 75.8 81.2 Up 11:00:23 - 11:17:10 969

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 54598, (2025/11/19 11:07UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:45:17.9 +28:01:33  1.1  9.94 116
32 Lyn         08:33:21.5 +36:26:11  6.5  3.35 108
PPM 073603     08:19:31.6 +35:02:44  7.6  0.25 110
54598          08:18:19.5 +35:03:24 15.0       110
Positions are for J2000

Event circumstances last updated at 2022/04/17 23:27:00 UT

Marc W. Buie, Southwest Research Institute

RECON