RECON: TNO occultation with 531683

Event between (531683) 12UC178 and star GA1080:00656659 with event index number of 2445130

Geocentric closest approach at 2025/12/26 05:17:53 UTC

J2000 position of star is 04:43:29.8 +19:50:05
Equinox of date position of star is 04:44:55.2 +19:52:43
Stellar brightness G=16.7, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 87 degrees from the moon. Moon is 33% illuminated.
Apparent brightness V=22.9

[RECON map]
Object is 40.4 AU from the Sun and 39.5 AU from the Earth.
Apparent velocity is 23.2 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 174 seconds.
The 1-sigma cross-track error in the shadow position is 1637 km.
The sky-plane scale is 28636.4 km/arcsec.

The object has an absolute magnitude Hv=6.8
Diameter=263.0 km assuming a 5% albedo -- 11.2 sec chord
Diameter=107.4 km assuming a 30% albedo -- 4.6 sec chord
Dynamical classification is 5:3EE
 
 
 
 
 
 

Star training set for 531683, (2025/12/26 05:18UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:24.9 +16:33:34  0.8  3.78  85
Alnath         05:27:56.2 +28:37:37  1.6 13.11  97
PPM 093646     04:39:48.0 +20:44:05  5.9  1.49  86
PPM 120231     04:47:48.0 +18:46:46  7.1  1.28  87
PPM 120171     04:44:24.3 +19:47:44  9.9  0.17  87
531683         04:45:01.6 +19:52:54 16.7        87
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 5.2 sigma about the mid-time.
The median site spacing is 32.7 km RECON observability=1.0 and success probability=0.0%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Kamloops 05:18:28 -48.3 Dark Up 56.5 150.8 Up 05:03:28 - 05:33:28 5732
Sleaford 05:17:45 -54.8 Dark Up 57.7 175.8 Up 05:02:45 - 05:32:45 5698
Kelowna 05:18:28 -49.2 Dark Up 57.5 151.6 Up 05:03:28 - 05:33:28 5645
Peachland 05:18:28 -49.0 Dark Up 57.5 151.1 Up 05:03:28 - 05:33:28 5639
Summerland 05:18:29 -49.2 Dark Up 57.6 151.1 Up 05:03:29 - 05:33:29 5624
Penticton 05:18:28 -49.2 Dark Up 57.7 151.2 Up 05:03:28 - 05:33:28 5616
Oliver 05:18:29 -49.4 Dark Up 58.0 151.0 Up 05:03:29 - 05:33:29 5583
Victoria 05:18:41 -47.3 Dark Up 57.2 144.2 Up 05:03:41 - 05:33:41 5580
Anarchist Mountain Observatory 05:18:28 -49.6 Dark Up 58.2 151.2 Up 05:03:28 - 05:33:28 5565
Okanogan 05:18:30 -49.7 Dark Up 58.7 150.3 Up 05:03:30 - 05:33:30 5507
Brewster 05:18:32 -49.7 Dark Up 58.9 149.7 Up 05:03:32 - 05:33:32 5485
Manson/Chelan 05:18:32 -49.6 Dark Up 59.0 148.9 Up 05:03:32 - 05:33:32 5471
Wenatchee 05:18:34 -49.6 Dark Up 59.3 148.2 Up 05:03:34 - 05:33:34 5429
Ellensburg 05:18:35 -49.7 Dark Up 59.6 147.5 Up 05:03:35 - 05:33:35 5393
Yakima 05:18:36 -49.8 Dark Up 59.9 147.1 Up 05:03:36 - 05:33:36 5355
Toppenish/White Swan 05:18:35 -50.0 Dark Up 60.2 147.2 Up 05:03:35 - 05:33:35 5332
PNWRO 05:18:32 -51.1 Dark Up 61.0 149.5 Up 05:03:32 - 05:33:32 5274
The Dalles 05:18:39 -49.7 Dark Up 60.5 145.1 Up 05:03:39 - 05:33:39 5270
Maupin 05:18:40 -50.0 Dark Up 60.9 144.8 Up 05:03:40 - 05:33:40 5228
Sisters 05:18:42 -49.9 Dark Up 61.4 143.1 Up 05:03:42 - 05:33:42 5152
Bend 05:18:42 -50.1 Dark Up 61.7 143.2 Up 05:03:42 - 05:33:42 5124
Oregon Observatory 05:18:42 -50.1 Dark Up 61.8 142.8 Up 05:03:42 - 05:33:42 5110
Chiloquin 05:18:45 -50.2 Dark Up 62.6 140.6 Up 05:03:45 - 05:33:45 4988
Klamath Falls 05:18:46 -50.3 Dark Up 62.9 140.3 Up 05:03:46 - 05:33:46 4953
Cedarville 05:18:41 -51.7 Dark Up 64.2 142.3 Up 05:03:41 - 05:33:41 4857
Fall River/Burney 05:18:46 -50.9 Dark Up 64.0 139.5 Up 05:03:46 - 05:33:46 4830
Greenville 05:18:46 -51.5 Dark Up 64.9 139.1 Up 05:03:46 - 05:33:46 4732
Gimple 05:18:46 -51.5 Dark Up 65.0 139.2 Up 05:03:46 - 05:33:46 4730
Quincy 05:18:46 -51.5 Dark Up 65.1 138.8 Up 05:03:46 - 05:33:46 4711
Portola 05:18:44 -51.9 Dark Up 65.4 139.5 Up 05:03:44 - 05:33:44 4690
Reno 05:18:43 -52.4 Dark Up 65.9 140.4 Up 05:03:43 - 05:33:43 4652
Carson City 05:18:43 -52.5 Dark Up 66.2 139.9 Up 05:03:43 - 05:33:43 4616
Gardnerville 05:18:44 -52.6 Dark Up 66.4 139.6 Up 05:03:44 - 05:33:44 4590
Yerington 05:18:42 -53.0 Dark Up 66.7 140.9 Up 05:03:42 - 05:33:42 4585
Hawthorne 05:18:40 -53.5 Dark Up 67.3 141.3 Up 05:03:40 - 05:33:40 4529
Dunrhomin 05:17:50 -62.5 Dark Up 69.5 175.7 Up 05:02:50 - 05:32:50 4525
Nikitin 05:17:50 -62.5 Dark Up 69.7 175.6 Up 05:02:50 - 05:32:50 4506
CU-SBO 05:17:51 -62.5 Dark Up 69.8 175.3 Up 05:02:51 - 05:32:51 4500
Lee Vining 05:18:43 -53.3 Dark Up 67.5 139.4 Up 05:03:43 - 05:33:43 4480
Bishop 05:18:41 -54.0 Dark Up 68.3 139.9 Up 05:03:41 - 05:33:41 4406
Beatty 05:18:36 -55.3 Dark Up 69.5 142.8 Up 05:03:36 - 05:33:36 4331
Patrick 05:18:26 -57.9 Dark Up 72.0 147.4 Up 05:03:26 - 05:33:26 4131
Laughlin/Bullhead City 05:18:29 -57.4 Dark Up 71.9 145.2 Up 05:03:29 - 05:33:29 4116
Wildwood 05:18:46 -54.4 Dark Up 70.6 133.6 Up 05:03:46 - 05:33:46 4071
Lake Havasu City 05:18:29 -57.7 Dark Up 72.6 144.6 Up 05:03:29 - 05:33:29 4042
Idyllwild 05:18:38 -55.9 Dark Up 72.0 137.1 Up 05:03:38 - 05:33:38 4001
George/Scottsdale 05:18:20 -59.9 Dark Up 74.3 150.3 Up 05:03:20 - 05:33:20 3923
Calipatria 05:18:35 -57.0 Dark Up 73.1 138.7 Up 05:03:35 - 05:33:35 3917
Yuma 05:18:32 -57.8 Dark Up 73.9 140.2 Up 05:03:32 - 05:33:32 3856

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 531683, (2025/12/26 05:18UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8  3.78  85
Alnath         05:26:17.6 +28:36:23  1.6 13.11  97
PPM 093646     04:38:15.8 +20:41:05  5.9  1.49  86
PPM 120231     04:46:16.9 +18:44:03  7.1  1.28  87
PPM 120171     04:42:52.7 +19:44:54  9.9  0.17  87
531683         04:43:29.8 +19:50:05 16.7        87
Positions are for J2000

Event circumstances last updated at 2024/03/04 05:37:46 UT

Marc W. Buie, Southwest Research Institute

RECON