RECON: TNO occultation with 307261

Event between (307261) 02MS4 and star GA0840:16688397 with event index number of 2185194

Geocentric closest approach at 2025/05/19 09:05:18 UTC

J2000 position of star is 19:14:21.4 -05:03:16
Equinox of date position of star is 19:15:38.5 -05:00:41
Stellar brightness G=14.2, use SENSEUP=64 with the MallinCam and and exposure time of 1 seconds with the QHY174 camera.
Star is 32 degrees from the moon. Moon is 62% illuminated.
Apparent brightness V=20.3

[RECON map]
Object is 46.1 AU from the Sun and 45.5 AU from the Earth.
Apparent velocity is 15.8 km/sec on the sky relative to the star, or, 1.7 arcsec/hr.
The 1-sigma error in the time of the event is 285 seconds.
The 1-sigma cross-track error in the shadow position is 2349 km.
The sky-plane scale is 32984.7 km/arcsec.

The object has an absolute magnitude Hv=3.6
Diameter=1066.6 km assuming a 5% albedo -- 72.0 sec chord
Diameter=435.5 km assuming a 30% albedo -- 29.4 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 

Star training set for 307261, (2025/05/19 09:05UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:58.1 -26:29:10  0.9 44.77  65
Tarazed        19:47:28.0 +10:40:36  2.7 17.57  37
26 Aql         19:21:54.1 -05:21:59  5.0  1.58  31
PPM 202644     19:13:48.5 -05:22:14  8.3  0.59  33
PPM 202673     19:15:19.1 -04:47:57  9.4  0.23  33
307261         19:15:42.3 -05:00:33 14.2        32
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 3.2 sigma about the mid-time.
The median site spacing is 18.9 km RECON observability=1.0 and success probability=5.9%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Sleaford 09:08:29 -12.8 AT Up 30.4 156.6 Up 08:53:29 - 09:23:29 5078
Kamloops 09:09:21 -17.7 AT Up 27.0 140.9 Low 08:54:21 - 09:24:21 4649
Kelowna 09:09:20 -18.3 Dark Up 27.9 141.6 Low 08:54:20 - 09:24:20 4607
Peachland 09:09:22 -18.5 Dark Up 27.9 141.3 Low 08:54:22 - 09:24:22 4592
Summerland 09:09:21 -18.6 Dark Up 28.1 141.3 Low 08:54:21 - 09:24:21 4582
Penticton 09:09:20 -18.7 Dark Up 28.2 141.4 Low 08:54:20 - 09:24:20 4580
Oliver 09:09:21 -19.0 Dark Up 28.4 141.3 Low 08:54:21 - 09:24:21 4552
Anarchist Mountain Observatory 09:09:21 -19.1 Dark Up 28.7 141.4 Low 08:54:21 - 09:24:21 4544
Okanogan 09:09:22 -19.8 Dark Up 29.1 141.0 Low 08:54:22 - 09:24:22 4488
Brewster 09:09:22 -20.1 Dark Up 29.2 140.7 Low 08:54:22 - 09:24:22 4462
Manson/Chelan 09:09:25 -20.3 Dark Up 29.2 140.2 Low 08:54:25 - 09:24:25 4436
Victoria 09:09:34 -20.3 Dark Down 27.3 137.2 Low 08:54:34 - 09:24:34 4412
Wenatchee 09:09:26 -20.8 Dark Up 29.5 139.9 Low 08:54:26 - 09:24:26 4394
Ellensburg 09:09:27 -21.3 Dark Up 29.7 139.5 Low 08:54:27 - 09:24:27 4356
Yakima 09:09:28 -21.7 Dark Up 30.0 139.4 Up 08:54:28 - 09:24:28 4322
PNWRO 09:09:22 -21.8 Dark Up 31.2 140.8 Up 08:54:22 - 09:24:22 4315
Toppenish/White Swan 09:09:29 -21.8 Dark Up 30.3 139.4 Up 08:54:29 - 09:24:29 4309
The Dalles 09:09:32 -22.7 Dark Up 30.5 138.3 Up 08:54:32 - 09:24:32 4225
Dunrhomin 09:08:27 -22.6 Dark Up 41.3 153.9 Up 08:53:27 - 09:23:27 4209
Nikitin 09:08:27 -22.7 Dark Up 41.5 153.8 Up 08:53:27 - 09:23:27 4194
Maupin 09:09:31 -23.1 Dark Up 30.8 138.3 Up 08:54:31 - 09:24:31 4193
CU-SBO 09:08:27 -22.8 Dark Up 41.5 153.7 Up 08:53:27 - 09:23:27 4186
Sisters 09:09:34 -24.1 Dark Up 31.3 137.4 Up 08:54:34 - 09:24:34 4108
Bend 09:09:33 -24.2 Dark Up 31.6 137.6 Up 08:54:33 - 09:24:33 4094
Oregon Observatory 09:09:35 -24.4 Dark Up 31.6 137.4 Up 08:54:35 - 09:24:35 4076
Chiloquin 09:09:37 -25.8 Dark Up 32.4 136.4 Up 08:54:37 - 09:24:37 3953
Klamath Falls 09:09:37 -26.1 Dark Up 32.7 136.4 Up 08:54:37 - 09:24:37 3925
Cedarville 09:09:32 -26.4 Dark Up 34.0 137.7 Up 08:54:32 - 09:24:32 3906
Fall River/Burney 09:09:36 -27.1 Dark Up 33.7 136.2 Up 08:54:36 - 09:24:36 3832
Gimple 09:09:36 -27.8 Dark Up 34.7 136.3 Up 08:54:36 - 09:24:36 3766
Greenville 09:09:37 -27.9 Dark Up 34.6 136.2 Up 08:54:37 - 09:24:37 3764
Portola 09:09:35 -28.1 Dark Up 35.1 136.6 Up 08:54:35 - 09:24:35 3748
Quincy 09:09:37 -28.1 Dark Up 34.8 136.2 Up 08:54:37 - 09:24:37 3746
Reno 09:09:31 -28.1 Dark Up 35.6 137.1 Up 08:54:31 - 09:24:31 3742
Carson City 09:09:32 -28.5 Dark Up 35.9 137.0 Up 08:54:32 - 09:24:32 3711
Yerington 09:09:29 -28.5 Dark Up 36.4 137.5 Up 08:54:29 - 09:24:29 3710
Gardnerville 09:09:31 -28.7 Dark Up 36.1 136.9 Up 08:54:31 - 09:24:31 3690
Hawthorne 09:09:28 -28.8 Dark Up 37.0 137.8 Up 08:54:28 - 09:24:28 3684
Lee Vining 09:09:31 -29.4 Dark Up 37.2 137.0 Up 08:54:31 - 09:24:31 3620
Beatty 09:09:21 -29.7 Dark Up 39.2 139.0 Up 08:54:21 - 09:24:21 3590
Bishop 09:09:28 -29.8 Dark Up 38.0 137.5 Up 08:54:28 - 09:24:28 3586
Patrick 09:09:07 -30.1 Dark Up 41.8 141.3 Up 08:54:07 - 09:24:07 3539
Laughlin/Bullhead City 09:09:11 -30.6 Dark Up 41.6 140.4 Up 08:54:11 - 09:24:11 3496
George/Scottsdale 09:08:57 -30.9 Dark Up 44.1 142.7 Up 08:53:57 - 09:23:57 3445
Lake Havasu City 09:09:10 -31.1 Dark Up 42.3 140.3 Up 08:54:10 - 09:24:10 3442
Idyllwild 09:09:20 -32.6 Dark Up 41.6 137.2 Up 08:54:20 - 09:24:20 3302
Calipatria 09:09:15 -32.8 Dark Up 42.7 138.1 Up 08:54:15 - 09:24:15 3280
Wildwood 09:09:29 -32.9 Dark Up 40.3 135.4 Up 08:54:29 - 09:24:29 3280
Yuma 09:09:11 -32.8 Dark Up 43.5 138.9 Up 08:54:11 - 09:24:11 3267

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, (2025/05/19 09:05UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 44.77  65
Tarazed        19:46:15.6 +10:36:48  2.7 17.57  37
26 Aql         19:20:33.1 -05:24:56  5.0  1.58  31
PPM 202644     19:12:27.4 -05:24:54  8.3  0.59  33
PPM 202673     19:13:58.3 -04:50:39  9.4  0.23  33
307261         19:14:21.4 -05:03:16 14.2        32
Positions are for J2000

Event circumstances last updated at 2024/03/02 06:15:35 UT

Marc W. Buie, Southwest Research Institute

RECON