RECON: TNO occultation with 531683

Event between (531683) 12UC178 and star GA1100:00743224 with event index number of 2445120

Geocentric closest approach at 2025/10/16 04:46:46 UTC

J2000 position of star is 04:49:10.4 +20:01:26
Equinox of date position of star is 04:50:36.0 +20:03:52
Stellar brightness G=16.9, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 70 degrees from the moon. Moon is 25% illuminated.
Apparent brightness V=23.0

[RECON map]
Object is 40.4 AU from the Sun and 39.7 AU from the Earth.
Apparent velocity is 14.6 km/sec on the sky relative to the star, or, 1.8 arcsec/hr.
The 1-sigma error in the time of the event is 292 seconds.
The 1-sigma cross-track error in the shadow position is 1578 km.
The sky-plane scale is 28810.9 km/arcsec.

The object has an absolute magnitude Hv=6.8
Diameter=263.0 km assuming a 5% albedo -- 17.8 sec chord
Diameter=107.4 km assuming a 30% albedo -- 7.3 sec chord
Dynamical classification is 5:3EE
 
 
 
 
 
 

Star training set for 531683, (2025/10/16 04:47UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:37:24.2 +16:33:33  0.8  4.72  73
Alnath         05:27:55.5 +28:37:37  1.6 12.04  60
97 Tau         04:52:53.1 +18:52:53  5.1  1.29  69
PPM 093789     04:50:16.0 +21:21:33  7.3  1.30  70
PPM 120310     04:51:46.6 +19:57:57  9.6  0.27  69
531683         04:50:41.7 +20:04:01 16.9        69
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 3.1 sigma about the mid-time.
The median site spacing is 12.3 km RECON observability=0.1 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 04:50:14 -34.7 Dark Down 12.2 73.2 Really Low 04:35:14 - 05:05:14 -2792
Victoria 04:50:24 -34.1 Dark Down 9.7 70.7 Really Low 04:35:24 - 05:05:24 -2826
Peachland 04:50:20 -35.6 Dark Down 12.3 73.5 Really Low 04:35:20 - 05:05:20 -2850
Kelowna 04:50:20 -35.7 Dark Down 12.6 73.7 Really Low 04:35:20 - 05:05:20 -2851
Summerland 04:50:21 -35.7 Dark Down 12.4 73.5 Really Low 04:35:21 - 05:05:21 -2859
Penticton 04:50:22 -35.8 Dark Down 12.4 73.6 Really Low 04:35:22 - 05:05:22 -2865
Oliver 04:50:23 -36.0 Dark Down 12.3 73.5 Really Low 04:35:23 - 05:05:23 -2883
Anarchist Mountain Observatory 04:50:25 -36.2 Dark Down 12.4 73.6 Really Low 04:35:25 - 05:05:25 -2895
Okanogan 04:50:29 -36.4 Dark Down 12.1 73.4 Really Low 04:35:29 - 05:05:29 -2923
Brewster 04:50:31 -36.5 Dark Down 11.9 73.2 Really Low 04:35:31 - 05:05:31 -2932
Manson/Chelan 04:50:31 -36.4 Dark Down 11.6 72.9 Really Low 04:35:31 - 05:05:31 -2934
Wenatchee 04:50:35 -36.5 Dark Down 11.3 72.7 Really Low 04:35:35 - 05:05:35 -2955
Ellensburg 04:50:38 -36.6 Dark Down 11.1 72.4 Really Low 04:35:38 - 05:05:38 -2971
Yakima 04:50:40 -36.8 Dark Down 10.9 72.4 Really Low 04:35:40 - 05:05:40 -2992
Toppenish/White Swan 04:50:41 -37.0 Dark Down 11.0 72.4 Really Low 04:35:41 - 05:05:41 -3008
The Dalles 04:50:46 -36.9 Dark Down 10.2 71.8 Really Low 04:35:46 - 05:05:46 -3031
Maupin 04:50:49 -37.2 Dark Down 10.2 71.8 Really Low 04:35:49 - 05:05:49 -3056
PNWRO 04:50:45 -38.1 Dark Down 11.9 73.4 Really Low 04:35:45 - 05:05:45 -3065
Sleaford 04:50:07 -40.5 Dark Down 21.3 84.4 Low 04:35:07 - 05:05:07 -3066
Sisters 04:50:54 -37.4 Dark Down 9.6 71.3 Really Low 04:35:54 - 05:05:54 -3093
Bend 04:50:54 -37.6 Dark Down 9.7 71.5 Really Low 04:35:54 - 05:05:54 -3113
Oregon Observatory 04:50:56 -37.6 Dark Down 9.6 71.3 Really Low 04:35:56 - 05:05:56 -3119
Chiloquin 04:51:04 -38.0 Dark Down 8.9 70.9 Really Low 04:36:04 - 05:06:04 -3186
Klamath Falls 04:51:05 -38.2 Dark Down 8.8 70.9 Really Low 04:36:05 - 05:06:05 -3208
Fall River/Burney 04:51:12 -39.0 Dark Down 8.7 71.0 Really Low 04:36:12 - 05:06:12 -3290
Cedarville 04:51:11 -39.6 Dark Down 9.7 71.8 Really Low 04:36:11 - 05:06:11 -3293
Greenville 04:51:19 -39.7 Dark Down 8.8 71.2 Really Low 04:36:19 - 05:06:19 -3359
Gimple 04:51:18 -39.8 Dark Down 8.8 71.2 Really Low 04:36:18 - 05:06:18 -3361
Quincy 04:51:19 -39.8 Dark Down 8.7 71.1 Really Low 04:36:19 - 05:06:19 -3372
Portola 04:51:21 -40.2 Dark Down 9.0 71.4 Really Low 04:36:21 - 05:06:21 -3392
Reno 04:51:23 -40.8 Dark Down 9.4 71.8 Really Low 04:36:23 - 05:06:23 -3427
Carson City 04:51:25 -41.0 Dark Down 9.3 71.7 Really Low 04:36:25 - 05:06:25 -3451
Gardnerville 04:51:27 -41.1 Dark Down 9.3 71.7 Really Low 04:36:27 - 05:06:27 -3468
Yerington 04:51:26 -41.5 Dark Down 9.7 72.1 Really Low 04:36:26 - 05:06:26 -3482
Hawthorne 04:51:30 -42.1 Dark Down 10.0 72.3 Really Low 04:36:30 - 05:06:30 -3528
Lee Vining 04:51:31 -42.0 Dark Down 9.5 71.9 Really Low 04:36:31 - 05:06:31 -3551
Bishop 04:51:35 -42.8 Dark Down 9.8 72.3 Really Low 04:36:35 - 05:06:35 -3613
Beatty 04:51:39 -44.2 Dark Down 11.0 73.1 Really Low 04:36:39 - 05:06:39 -3693
Dunrhomin 04:51:19 -49.6 Dark Down 20.5 80.6 Low 04:36:19 - 05:06:19 -3812
Nikitin 04:51:21 -49.7 Dark Down 20.4 80.6 Low 04:36:21 - 05:06:21 -3824
CU-SBO 04:51:21 -49.7 Dark Down 20.4 80.5 Low 04:36:21 - 05:06:21 -3826
Wildwood 04:51:54 -44.0 Dark Down 8.7 71.7 Really Low 04:36:54 - 05:06:54 -3837
Laughlin/Bullhead City 04:51:50 -46.6 Dark Down 12.2 74.0 Really Low 04:36:50 - 05:06:50 -3883
Patrick 04:51:48 -46.9 Dark Down 12.8 74.4 Really Low 04:36:48 - 05:06:48 -3887
Idyllwild 04:51:57 -45.6 Dark Down 10.1 72.6 Really Low 04:36:57 - 05:06:57 -3921
Lake Havasu City 04:51:54 -47.1 Dark Down 12.2 74.0 Really Low 04:36:54 - 05:06:54 -3940
Calipatria 04:52:00 -46.8 Dark Down 10.9 73.1 Really Low 04:37:00 - 05:07:00 -4004
Yuma 04:52:03 -47.7 Dark Down 11.5 73.5 Really Low 04:37:03 - 05:07:03 -4065
George/Scottsdale 04:51:56 -49.2 Dark Down 14.0 75.1 Really Low 04:36:56 - 05:06:56 -4076

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, (2025/10/16 04:47UT)
Object            RA         Dec     mag  sep  mel
Aldebaran      04:35:55.3 +16:30:29  0.8  4.72  73
Alnath         05:26:17.6 +28:36:23  1.6 12.04  60
97 Tau         04:51:22.6 +18:50:23  5.1  1.29  69
PPM 093789     04:48:43.8 +21:18:56  7.3  1.30  70
PPM 120310     04:50:15.3 +19:55:24  9.6  0.27  69
531683         04:49:10.4 +20:01:26 16.9        70
Positions are for J2000

Event circumstances last updated at 2024/03/03 06:04:18 UT

Marc W. Buie, Southwest Research Institute

RECON