RECON: TNO occultation with 307261

Event between (307261) 02MS4 and star GA0840:16779450 with event index number of 2185400

Geocentric closest approach at 2026/07/11 05:12:46 UTC

J2000 position of star is 19:15:20.1 -04:45:54
Equinox of date position of star is 19:16:36.9 -04:43:17
Stellar brightness G=16.0, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 130 degrees from the moon. Moon is 15% illuminated.
Apparent brightness V=20.2

[RECON map]
Object is 46.0 AU from the Sun and 45.0 AU from the Earth.
Apparent velocity is 25.2 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 188 seconds.
The 1-sigma cross-track error in the shadow position is 1917 km.
The sky-plane scale is 32650.5 km/arcsec.

The object has an absolute magnitude Hv=3.6
Diameter=1066.6 km assuming a 5% albedo -- 45.2 sec chord
Diameter=435.5 km assuming a 30% albedo -- 18.4 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 

Star training set for 307261, (2026/07/11 05:13UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:02.3 -26:29:19  0.9 45.13 174
Tarazed        19:47:31.2 +10:40:47  2.7 17.20 115
26 Aql         19:21:57.8 -05:21:51  5.0  1.45 129
PPM 202728     19:18:21.5 -04:36:18  8.5  0.42 129
PPM 202706     19:17:07.2 -04:52:44  9.1  0.19 130
307261         19:16:44.4 -04:43:01 16.0       129
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 4.8 sigma about the mid-time.
The median site spacing is 22.1 km RECON observability=0.5 and success probability=9.6%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Sleaford 05:13:33 -11.6 NT Down 28.6 148.7 Low 04:58:33 - 05:28:33 -506
Kamloops 05:14:09 -7.9 NT Down 24.1 133.6 Low 04:59:09 - 05:29:09 -538
Kelowna 05:14:09 -8.9 NT Down 25.1 134.2 Low 04:59:09 - 05:29:09 -587
Peachland 05:14:10 -8.8 NT Down 25.0 133.9 Low 04:59:10 - 05:29:10 -593
Summerland 05:14:10 -9.0 NT Down 25.2 134.0 Low 04:59:10 - 05:29:10 -602
Penticton 05:14:10 -9.1 NT Down 25.3 134.0 Low 04:59:10 - 05:29:10 -607
Oliver 05:14:11 -9.4 NT Down 25.5 133.9 Low 04:59:11 - 05:29:11 -628
Anarchist Mountain Observatory 05:14:11 -9.6 NT Down 25.7 134.0 Low 04:59:11 - 05:29:11 -638
Victoria 05:14:21 -8.2 NT Down 24.1 130.0 Low 04:59:21 - 05:29:21 -660
Okanogan 05:14:13 -10.0 NT Down 26.1 133.6 Low 04:59:13 - 05:29:13 -678
Brewster 05:14:14 -10.1 NT Down 26.2 133.3 Low 04:59:14 - 05:29:14 -694
Manson/Chelan 05:14:15 -10.1 NT Down 26.1 132.9 Low 04:59:15 - 05:29:15 -706
Wenatchee 05:14:17 -10.4 NT Down 26.4 132.6 Low 04:59:17 - 05:29:17 -735
Ellensburg 05:14:18 -10.6 NT Down 26.5 132.2 Low 04:59:18 - 05:29:18 -761
Yakima 05:14:19 -10.9 NT Down 26.8 132.1 Low 04:59:19 - 05:29:19 -787
Toppenish/White Swan 05:14:19 -11.2 NT Down 27.0 132.1 Low 04:59:19 - 05:29:19 -802
PNWRO 05:14:17 -12.1 AT Down 28.1 133.4 Low 04:59:17 - 05:29:17 -829
The Dalles 05:14:23 -11.4 NT Down 27.2 131.1 Low 04:59:23 - 05:29:23 -851
Maupin 05:14:24 -11.8 NT Down 27.5 131.0 Low 04:59:24 - 05:29:24 -878
Sisters 05:14:27 -12.2 AT Down 27.8 130.2 Low 04:59:27 - 05:29:27 -936
Bend 05:14:27 -12.5 AT Down 28.1 130.4 Low 04:59:27 - 05:29:27 -953
Oregon Observatory 05:14:28 -12.6 AT Down 28.1 130.2 Low 04:59:28 - 05:29:28 -964
Chiloquin 05:14:32 -13.4 AT Down 28.8 129.3 Low 04:59:32 - 05:29:32 -1055
Klamath Falls 05:14:33 -13.7 AT Down 29.0 129.2 Low 04:59:33 - 05:29:33 -1079
Cedarville 05:14:30 -15.0 AT Down 30.4 130.4 Up 04:59:30 - 05:29:30 -1133
Fall River/Burney 05:14:34 -14.7 AT Down 30.0 129.0 Low 04:59:34 - 05:29:34 -1165
Greenville 05:14:35 -15.6 AT Down 30.8 129.0 Up 04:59:35 - 05:29:35 -1233
Gimple 05:14:35 -15.7 AT Down 30.9 129.1 Up 04:59:35 - 05:29:35 -1233
Quincy 05:14:35 -15.8 AT Down 31.0 129.0 Up 04:59:35 - 05:29:35 -1248
Portola 05:14:35 -16.1 AT Down 31.3 129.3 Up 04:59:35 - 05:29:35 -1258
Reno 05:14:34 -16.7 AT Down 31.9 129.8 Up 04:59:34 - 05:29:34 -1280
Dunrhomin 05:13:52 -22.4 Dark Down 38.9 145.3 Up 04:58:52 - 05:28:52 -1290
Nikitin 05:13:52 -22.5 Dark Down 39.0 145.2 Up 04:58:52 - 05:28:52 -1304
Carson City 05:14:35 -16.9 AT Down 32.1 129.7 Up 04:59:35 - 05:29:35 -1307
CU-SBO 05:13:53 -22.6 Dark Down 39.0 145.1 Up 04:58:53 - 05:28:53 -1308
Yerington 05:14:33 -17.4 AT Down 32.6 130.2 Up 04:59:33 - 05:29:33 -1324
Gardnerville 05:14:35 -17.2 AT Down 32.3 129.6 Up 04:59:35 - 05:29:35 -1326
Hawthorne 05:14:33 -18.0 Dark Down 33.2 130.5 Up 04:59:33 - 05:29:33 -1361
Lee Vining 05:14:35 -18.2 Dark Down 33.3 129.7 Up 04:59:35 - 05:29:35 -1402
Bishop 05:14:35 -19.1 Dark Down 34.1 130.1 Up 04:59:35 - 05:29:35 -1452
Beatty 05:14:31 -20.2 Dark Down 35.4 131.4 Up 04:59:31 - 05:29:31 -1494
Patrick 05:14:26 -22.8 Dark Down 38.1 133.5 Up 04:59:26 - 05:29:26 -1624
Laughlin/Bullhead City 05:14:29 -22.7 Dark Down 37.9 132.6 Up 04:59:29 - 05:29:29 -1641
Lake Havasu City 05:14:29 -23.3 Dark Down 38.5 132.5 Up 04:59:29 - 05:29:29 -1697
Wildwood 05:14:35 -21.4 Dark Down 36.1 128.1 Up 04:59:35 - 05:29:35 -1723
Idyllwild 05:14:35 -22.7 Dark Down 37.5 129.7 Up 04:59:35 - 05:29:35 -1751
George/Scottsdale 05:14:23 -25.2 Dark Down 40.5 134.5 Up 04:59:23 - 05:29:23 -1773
Calipatria 05:14:35 -23.8 Dark Down 38.7 130.5 Up 04:59:35 - 05:29:35 -1806
Yuma 05:14:33 -24.6 Dark Down 39.5 131.1 Up 04:59:33 - 05:29:33 -1846

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 307261, (2026/07/11 05:13UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 45.13 174
Tarazed        19:46:15.6 +10:36:48  2.7 17.20 115
26 Aql         19:20:33.1 -05:24:56  5.0  1.45 129
PPM 202728     19:16:57.2 -04:39:15  8.5  0.42 129
PPM 202706     19:15:42.7 -04:55:38  9.1  0.19 130
307261         19:15:20.1 -04:45:54 16.0       130
Positions are for J2000

Event circumstances last updated at 2024/03/05 04:30:14 UT

Marc W. Buie, Southwest Research Institute

RECON