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 11:06:07 UTC

J2000 position of star is 08:18:19.5 +35:03:24
Equinox of date position of star is 08:19:37.0 +34:59:34
Stellar brightness G=15.0, use SENSEUP=128
Star is 110 degrees from the moon. Moon is 1% illuminated.
TNO apparent brightness V=21.5

[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 218 seconds.
The 1-sigma cross-track error in the shadow position is 1435 km.
The sky-plane scale is 9291.7 km/arcsec.

The TNO has an absolute magnitude Hv=10.0
Diameter=190.6 km assuming a 5% albedo -- 8.1 sec chord
Diameter=77.8 km assuming a 30% albedo -- 3.3 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 

Star training set for 54598, (2025/11/19 11:06UT)
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 4.1 sigma about the mid-time.
The median site spacing is 14.7 km RECON observability=1.0 and success probability=15.1%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Clarence Fulton 11:10:50 -38.9 Dark Down 70.2 133.5 Up 10:55:50 - 11:25:50 2934
Kelowna 11:10:48 -39.1 Dark Down 70.4 132.4 Up 10:55:48 - 11:25:48 2892
Peachland 11:10:50 -39.3 Dark Down 70.3 131.6 Up 10:55:50 - 11:25:50 2869
Summerland 11:10:47 -39.3 Dark Down 70.5 131.5 Up 10:55:47 - 11:25:47 2860
Penticton 11:10:46 -39.3 Dark Down 70.6 131.5 Up 10:55:46 - 11:25:46 2859
Oliver 11:10:43 -39.4 Dark Down 70.8 130.7 Up 10:55:43 - 11:25:43 2827
Anarchist Mountain Observatory 11:10:41 -39.3 Dark Down 71.0 130.7 Up 10:55:41 - 11:25:41 2820
Niwot 11:07:26 -31.1 Dark Down 84.0 145.6 Up 10:52:26 - 11:22:26 2812
SwRI 11:07:26 -31.2 Dark Down 84.0 144.4 Up 10:52:26 - 11:22:26 2798
Tonasket 11:10:36 -39.5 Dark Down 71.2 129.9 Up 10:55:36 - 11:25:36 2790
Okanogan 11:10:36 -39.7 Dark Down 71.3 128.8 Up 10:55:36 - 11:25:36 2753
Brewster 11:10:34 -39.9 Dark Down 71.4 127.8 Up 10:55:34 - 11:25:34 2720
Manson/Chelan 11:10:38 -40.2 Dark Down 71.3 126.6 Up 10:55:38 - 11:25:38 2685
Entiat 11:10:36 -40.3 Dark Down 71.4 125.9 Up 10:55:36 - 11:25:36 2662
Wenatchee 11:10:34 -40.4 Dark Down 71.5 125.1 Up 10:55:34 - 11:25:34 2635
Victoria 11:11:07 -42.0 Dark Down 69.2 122.4 Up 10:56:07 - 11:26:07 2605
Ellensburg 11:10:31 -40.7 Dark Down 71.6 123.6 Up 10:55:31 - 11:25:31 2588
Pasco 11:10:15 -40.0 Dark Down 72.8 124.3 Up 10:55:15 - 11:25:15 2585
PNWRO 11:10:12 -39.9 Dark Down 73.0 124.1 Up 10:55:12 - 11:25:12 2573
Yakima 11:10:29 -40.8 Dark Down 71.8 122.5 Up 10:55:29 - 11:25:29 2550
Toppenish/White Swan 11:10:26 -40.8 Dark Down 72.0 122.3 Up 10:55:26 - 11:25:26 2538
Goldendale 11:10:25 -41.2 Dark Down 72.0 120.0 Up 10:55:25 - 11:25:25 2469
The Dalles 11:10:25 -41.5 Dark Down 71.9 118.8 Up 10:55:25 - 11:25:25 2432
Maupin 11:10:22 -41.5 Dark Down 72.2 117.8 Up 10:55:22 - 11:25:22 2399
Redmond 11:10:17 -41.8 Dark Down 72.5 115.1 Up 10:55:17 - 11:25:17 2312
Sisters 11:10:17 -42.1 Dark Down 72.2 114.5 Up 10:55:17 - 11:25:17 2296
Bend 11:10:15 -42.0 Dark Down 72.5 114.2 Up 10:55:15 - 11:25:15 2286
Oregon Observatory 11:10:13 -42.1 Dark Down 72.5 113.5 Up 10:55:13 - 11:25:13 2264
La Pine/Gilchrist 11:10:13 -42.2 Dark Down 72.5 112.8 Up 10:55:13 - 11:25:13 2243
North Lake 11:10:04 -41.9 Dark Down 73.0 112.4 Up 10:55:04 - 11:25:04 2231
Paisley 11:09:57 -41.8 Dark Down 73.5 111.2 Up 10:54:57 - 11:24:57 2199
Lakeview 11:09:51 -41.8 Dark Down 73.8 109.9 Up 10:54:51 - 11:24:51 2162
Cedarville 11:09:43 -41.8 Dark Down 74.1 107.9 Up 10:54:43 - 11:24:43 2111
Klamath Falls 11:10:04 -42.8 Dark Down 72.8 108.0 Up 10:55:04 - 11:25:04 2098
Fall River/Burney 11:09:52 -42.8 Dark Down 73.4 104.7 Up 10:54:52 - 11:24:52 2009
Susanville 11:09:38 -42.4 Dark Down 74.0 103.5 Up 10:54:38 - 11:24:38 1988
Tonopah 11:08:49 -40.3 Dark Down 76.9 98.4 Up 10:53:49 - 11:23:49 1954
Gimple 11:09:38 -42.6 Dark Down 73.9 102.3 Up 10:54:38 - 11:24:38 1952
Reno 11:09:24 -42.0 Dark Down 74.8 101.4 Up 10:54:24 - 11:24:24 1951
Greenville 11:09:38 -42.7 Dark Down 73.9 102.2 Up 10:54:38 - 11:24:38 1948
Portola 11:09:31 -42.4 Dark Down 74.3 101.6 Up 10:54:31 - 11:24:31 1942
Yerington 11:09:13 -41.6 Dark Down 75.4 100.1 Up 10:54:13 - 11:24:13 1935
Quincy 11:09:38 -42.7 Dark Down 73.9 101.5 Up 10:54:38 - 11:24:38 1930
DCO 11:07:44 -37.4 Dark Down 80.1 86.8 Up 10:52:44 - 11:22:44 1928
Hawthorne 11:09:06 -41.3 Dark Down 75.8 98.9 Up 10:54:06 - 11:24:06 1921
Carson City 11:09:19 -42.0 Dark Down 74.9 100.1 Up 10:54:19 - 11:24:19 1920
Patrick 11:07:53 -38.0 Dark Down 79.6 88.3 Up 10:52:53 - 11:22:53 1913
Indian Springs 11:08:21 -39.3 Dark Down 78.2 93.1 Up 10:53:21 - 11:23:21 1909
Henderson 11:08:09 -38.8 Dark Down 78.7 91.0 Up 10:53:09 - 11:23:09 1903
Gardnerville 11:09:19 -42.0 Dark Down 74.9 99.3 Up 10:54:19 - 11:24:19 1901
George/Scottsdale 11:07:19 -36.4 Dark Down 80.9 78.4 Up 10:52:19 - 11:22:19 1890
Kingman/Dolan Springs 11:07:53 -38.1 Dark Down 79.4 87.0 Up 10:52:53 - 11:22:53 1883
Beatty 11:08:33 -40.1 Dark Down 77.4 93.8 Up 10:53:33 - 11:23:33 1878
Searchlight/Boulder City 11:08:03 -38.8 Dark Down 78.8 88.1 Up 10:53:03 - 11:23:03 1857
Laughlin/Bullhead City 11:07:57 -38.5 Dark Down 79.0 86.7 Up 10:52:57 - 11:22:57 1852
Lee Vining 11:09:03 -41.7 Dark Down 75.5 96.2 Up 10:54:03 - 11:24:03 1846
Bishop 11:08:52 -41.3 Dark Down 76.1 94.4 Up 10:53:52 - 11:23:52 1831
Mohave Valley 11:07:56 -38.5 Dark Down 79.0 85.3 Up 10:52:56 - 11:22:56 1829
Lake Havasu City 11:07:49 -38.4 Dark Down 79.1 83.3 Up 10:52:49 - 11:22:49 1809
Parker 11:07:46 -38.4 Dark Down 79.1 81.5 Up 10:52:46 - 11:22:46 1781
Blythe 11:07:43 -38.6 Dark Down 78.8 78.9 Up 10:52:43 - 11:22:43 1719
Yuma 11:07:35 -38.7 Dark Down 78.5 74.4 Up 10:52:35 - 11:22:35 1639
Calipatria 11:07:47 -39.4 Dark Down 77.9 76.8 Up 10:52:47 - 11:22:47 1623
Idyllwild 11:08:03 -40.3 Dark Down 77.1 79.7 Up 10:53:03 - 11:23:03 1607
Wildwood 11:08:25 -41.8 Dark Down 75.7 81.2 Up 10:53:25 - 11:23:25 1534
CPSLO 11:08:54 -43.3 Dark Down 74.3 85.3 Up 10:53:54 - 11:23:54 1530

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 11:06UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:45:18.0 +28:01:33  1.1  9.94 116
32 Lyn         08:33:21.5 +36:26:11  6.5  3.35 108
PPM 073603     08:19:31.7 +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 2020/02/28 22:39:11 UT

Marc W. Buie, Southwest Research Institute

RECON