RECON: TNO occultation with 523790

Event between (523790) 15HP9 and star GA0680:23474407 with event index number of 2605098

Geocentric closest approach at 2026/07/31 05:54:56 UTC

J2000 position of star is 18:14:59.0 -21:05:37
Equinox of date position of star is 18:16:26.8 -21:05:03
Stellar brightness G=16.5, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 53 degrees from the moon. Moon is 97% illuminated.
Apparent brightness V=23.0

[RECON map]
Object is 17.6 AU from the Sun and 16.7 AU from the Earth.
Apparent velocity is 17.2 km/sec on the sky relative to the star, or, 5.1 arcsec/hr.
The 1-sigma error in the time of the event is 352 seconds.
The 1-sigma cross-track error in the shadow position is 753 km.
The sky-plane scale is 12120.7 km/arcsec.

The object has an absolute magnitude Hv=10.5
Diameter=50.1 km assuming a 5% albedo -- 2.8 sec chord
Diameter=20.5 km assuming a 30% albedo -- 1.1 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 

Star training set for 523790, (2026/07/31 05:55UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:02.5 -26:29:19  0.9 24.69  77
Nunki          18:56:54.7 -26:15:40  2.0 10.58  44
13Mu Sgr       18:15:21.2 -21:02:58  3.9  0.29  54
PPM 268119     18:16:37.4 -20:51:40  8.3  0.22  53
523790         18:16:34.4 -21:05:00 16.5        53
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 2.6 sigma about the mid-time.
The median site spacing is 18.1 km RECON observability=0.8 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 05:54:16 -15.1 AT Up 18.2 183.3 Really Low 05:39:16 - 06:09:16 5783
Kelowna 05:54:12 -16.1 AT Up 18.9 184.2 Really Low 05:39:12 - 06:09:12 5747
Peachland 05:54:13 -16.1 AT Up 19.1 183.9 Really Low 05:39:13 - 06:09:13 5746
Summerland 05:54:13 -16.2 AT Up 19.2 184.0 Really Low 05:39:13 - 06:09:13 5739
Penticton 05:54:12 -16.3 AT Up 19.3 184.1 Really Low 05:39:12 - 06:09:12 5736
Victoria 05:54:28 -15.8 AT Up 20.4 180.3 Low 05:39:28 - 06:09:28 5723
Oliver 05:54:12 -16.6 AT Up 19.6 184.1 Really Low 05:39:12 - 06:09:12 5723
Anarchist Mountain Observatory 05:54:11 -16.8 AT Up 19.8 184.3 Really Low 05:39:11 - 06:09:11 5715
Sleaford 05:53:21 -17.7 AT Up 15.2 196.9 Really Low 05:38:21 - 06:08:21 5691
Okanogan 05:54:12 -17.3 AT Up 20.4 184.1 Low 05:39:12 - 06:09:12 5691
Brewster 05:54:13 -17.5 AT Up 20.7 183.9 Low 05:39:13 - 06:09:13 5682
Manson/Chelan 05:54:15 -17.5 AT Up 20.9 183.5 Low 05:39:15 - 06:09:15 5676
Wenatchee 05:54:15 -17.8 AT Up 21.4 183.4 Low 05:39:15 - 06:09:15 5658
Ellensburg 05:54:16 -18.1 Dark Up 21.9 183.2 Low 05:39:16 - 06:09:16 5643
Yakima 05:54:17 -18.4 Dark Up 22.3 183.2 Low 05:39:17 - 06:09:17 5626
Toppenish/White Swan 05:54:16 -18.7 Dark Up 22.5 183.3 Low 05:39:16 - 06:09:16 5615
PNWRO 05:54:09 -19.5 Dark Up 22.8 184.8 Low 05:39:09 - 06:09:09 5588
The Dalles 05:54:19 -19.0 Dark Up 23.3 182.6 Low 05:39:19 - 06:09:19 5587
Maupin 05:54:19 -19.4 Dark Up 23.7 182.7 Low 05:39:19 - 06:09:19 5568
Sisters 05:54:21 -19.9 Dark Up 24.6 182.2 Low 05:39:21 - 06:09:21 5532
Bend 05:54:20 -20.2 Dark Up 24.8 182.5 Low 05:39:20 - 06:09:20 5519
Oregon Observatory 05:54:20 -20.3 Dark Up 25.0 182.3 Low 05:39:20 - 06:09:20 5512
Chiloquin 05:54:23 -21.2 Dark Up 26.3 181.9 Low 05:39:23 - 06:09:23 5452
Klamath Falls 05:54:22 -21.5 Dark Up 26.7 182.0 Low 05:39:22 - 06:09:22 5434
Cedarville 05:54:15 -22.8 Dark Up 27.3 183.7 Low 05:39:15 - 06:09:15 5387
Fall River/Burney 05:54:20 -22.7 Dark Up 27.8 182.4 Low 05:39:20 - 06:09:20 5371
Greenville 05:54:18 -23.6 Dark Up 28.7 182.9 Low 05:39:18 - 06:09:18 5320
Gimple 05:54:18 -23.6 Dark Up 28.7 183.0 Low 05:39:18 - 06:09:18 5319
Quincy 05:54:18 -23.8 Dark Up 28.9 182.9 Low 05:39:18 - 06:09:18 5309
Portola 05:54:16 -24.1 Dark Up 29.0 183.4 Low 05:39:16 - 06:09:16 5299
Reno 05:54:13 -24.6 Dark Up 29.3 184.1 Low 05:39:13 - 06:09:13 5278
Carson City 05:54:13 -24.9 Dark Up 29.6 184.2 Low 05:39:13 - 06:09:13 5258
Gardnerville 05:54:13 -25.1 Dark Up 29.9 184.2 Low 05:39:13 - 06:09:13 5245
Yerington 05:54:10 -25.3 Dark Up 29.8 184.8 Low 05:39:10 - 06:09:10 5242
Hawthorne 05:54:07 -25.9 Dark Up 30.2 185.4 Up 05:39:07 - 06:09:07 5211
Lee Vining 05:54:09 -26.2 Dark Up 30.8 184.9 Up 05:39:09 - 06:09:09 5184
Bishop 05:54:06 -27.0 Dark Up 31.3 185.7 Up 05:39:06 - 06:09:06 5142
Dunrhomin 05:53:04 -29.0 Dark Up 26.3 199.0 Low 05:38:04 - 06:08:04 5137
Nikitin 05:53:04 -29.2 Dark Up 26.5 199.0 Low 05:38:04 - 06:08:04 5127
CU-SBO 05:53:04 -29.2 Dark Up 26.6 199.0 Low 05:38:04 - 06:08:04 5125
Beatty 05:53:58 -28.1 Dark Up 31.6 187.5 Up 05:38:58 - 06:08:58 5098
Patrick 05:53:43 -30.5 Dark Up 32.8 190.8 Up 05:38:43 - 06:08:43 4974
Laughlin/Bullhead City 05:53:46 -30.4 Dark Up 33.1 190.0 Up 05:38:46 - 06:08:46 4966
Wildwood 05:54:07 -29.6 Dark Up 34.6 185.7 Up 05:39:07 - 06:09:07 4944
Lake Havasu City 05:53:45 -31.1 Dark Up 33.7 190.4 Up 05:38:45 - 06:08:45 4921
Idyllwild 05:53:57 -30.7 Dark Up 34.8 187.8 Up 05:38:57 - 06:08:57 4901
Calipatria 05:53:51 -31.8 Dark Up 35.2 189.2 Up 05:38:51 - 06:08:51 4847
George/Scottsdale 05:53:32 -32.8 Dark Up 34.1 193.2 Up 05:38:32 - 06:08:32 4839
Yuma 05:53:46 -32.5 Dark Up 35.5 190.3 Up 05:38:46 - 06:08:46 4808

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 523790, (2026/07/31 05:55UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 24.69  77
Nunki          18:55:15.9 -26:17:49  2.0 10.58  44
13Mu Sgr       18:13:45.8 -21:03:32  3.9  0.29  54
PPM 268119     18:15:02.2 -20:52:16  8.3  0.22  53
523790         18:14:59.0 -21:05:37 16.5        53
Positions are for J2000

Event circumstances last updated at 2024/06/19 21:32:15 UT

Marc W. Buie, Southwest Research Institute

RECON