RECON: TNO occultation with 503858

Event between (503858) 98HQ151 and star GA0780:20460032 with event index number of 2452911

Geocentric closest approach at 2026/06/24 11:12:32 UTC

J2000 position of star is 19:37:38.2 -10:14:06
Equinox of date position of star is 19:38:56.2 -10:10:49
Stellar brightness G=16.8, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 83 degrees from the moon. Moon is 74% illuminated.
Apparent brightness V=24.2

[RECON map]
Object is 34.4 AU from the Sun and 33.5 AU from the Earth.
Apparent velocity is 22.1 km/sec on the sky relative to the star, or, 3.3 arcsec/hr.
The 1-sigma error in the time of the event is 306 seconds.
The 1-sigma cross-track error in the shadow position is 2238 km.
The sky-plane scale is 24283.7 km/arcsec.

The object has an absolute magnitude Hv=8.8
Diameter=104.7 km assuming a 5% albedo -- 4.8 sec chord
Diameter=42.8 km assuming a 30% albedo -- 2.0 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 

Star training set for 503858, (2026/06/24 11:00UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:02.1 -26:29:18  0.9 47.20  37
Nunki          18:56:54.3 -26:15:41  2.0 18.93  70
37 Aql         19:36:34.7 -10:30:02  4.7  0.70  83
PPM 236244     19:38:17.9 -10:05:48  6.9  0.21  83
503858         19:39:05.4 -10:10:26 16.8        84
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 2.9 sigma about the mid-time.
The median site spacing is 0.0 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 11:11:01 -5.2 CT Down 25.1 208.0 Low 10:56:01 - 11:26:01 7927
Kelowna 11:10:58 -5.4 CT Down 25.6 209.1 Low 10:55:58 - 11:25:58 7872
Sleaford 11:10:26 2.3 Sun up Down 18.9 221.9 Really Low 10:55:26 - 11:25:26 7869
Peachland 11:10:58 -5.7 CT Down 25.8 208.8 Low 10:55:58 - 11:25:58 7868
Summerland 11:10:57 -5.7 CT Down 25.9 209.0 Low 10:55:57 - 11:25:57 7858
Penticton 11:10:57 -5.7 CT Down 25.9 209.1 Low 10:55:57 - 11:25:57 7853
Oliver 11:10:57 -6.0 CT Down 26.2 209.2 Low 10:55:57 - 11:25:57 7832
Victoria 11:11:07 -8.1 NT Down 28.0 205.3 Low 10:56:07 - 11:26:07 7826
Anarchist Mountain Observatory 11:10:56 -6.0 NT Down 26.3 209.4 Low 10:55:56 - 11:25:56 7820
Okanogan 11:10:56 -6.6 NT Down 26.9 209.3 Low 10:55:56 - 11:25:56 7783
Brewster 11:10:56 -6.9 NT Down 27.2 209.2 Low 10:55:56 - 11:25:56 7768
Manson/Chelan 11:10:57 -7.2 NT Down 27.5 208.9 Low 10:55:57 - 11:25:57 7758
Wenatchee 11:10:57 -7.6 NT Down 28.0 208.8 Low 10:55:57 - 11:25:57 7730
Ellensburg 11:10:57 -8.0 NT Down 28.4 208.7 Low 10:55:57 - 11:25:57 7706
Yakima 11:10:57 -8.3 NT Down 28.8 208.8 Low 10:55:57 - 11:25:57 7680
Toppenish/White Swan 11:10:55 -8.4 NT Down 28.9 209.0 Low 10:55:55 - 11:25:55 7665
PNWRO 11:10:50 -8.0 NT Down 28.8 210.7 Low 10:55:50 - 11:25:50 7627
The Dalles 11:10:57 -9.4 NT Down 29.9 208.4 Low 10:55:57 - 11:25:57 7622
Maupin 11:10:56 -9.6 NT Down 30.2 208.6 Up 10:55:56 - 11:25:56 7594
Sisters 11:10:56 -10.5 NT Down 31.2 208.3 Up 10:55:56 - 11:25:56 7540
Bend 11:10:55 -10.6 NT Down 31.3 208.7 Up 10:55:55 - 11:25:55 7521
Oregon Observatory 11:10:56 -10.8 NT Down 31.5 208.6 Up 10:55:56 - 11:25:56 7511
Chiloquin 11:10:55 -12.0 NT Down 32.8 208.5 Up 10:55:55 - 11:25:55 7424
Klamath Falls 11:10:55 -12.2 AT Down 33.1 208.7 Up 10:55:55 - 11:25:55 7399
Cedarville 11:10:48 -11.9 NT Down 33.1 210.7 Up 10:55:48 - 11:25:48 7334
Fall River/Burney 11:10:53 -12.9 AT Down 34.0 209.5 Up 10:55:53 - 11:25:53 7311
Greenville 11:10:49 -13.3 AT Down 34.6 210.3 Up 10:55:49 - 11:25:49 7241
Gimple 11:10:49 -13.3 AT Down 34.5 210.4 Up 10:55:49 - 11:25:49 7240
Quincy 11:10:49 -13.4 AT Down 34.7 210.4 Up 10:55:49 - 11:25:49 7226
Portola 11:10:47 -13.3 AT Down 34.7 210.9 Up 10:55:47 - 11:25:47 7212
Reno 11:10:45 -13.1 AT Down 34.6 211.7 Up 10:55:45 - 11:25:45 7185
Carson City 11:10:44 -13.4 AT Down 34.9 211.9 Up 10:55:44 - 11:25:44 7158
Gardnerville 11:10:44 -13.5 AT Down 35.1 212.0 Up 10:55:44 - 11:25:44 7139
Yerington 11:10:42 -13.2 AT Down 34.8 212.6 Up 10:55:42 - 11:25:42 7137
Hawthorne 11:10:39 -13.2 AT Down 35.0 213.4 Up 10:55:39 - 11:25:39 7096
Dunrhomin 11:09:59 -4.3 CT Down 27.1 226.0 Low 10:54:59 - 11:24:59 7064
Lee Vining 11:10:40 -13.9 AT Down 35.7 213.1 Up 10:55:40 - 11:25:40 7058
Nikitin 11:09:59 -4.4 CT Down 27.3 226.0 Low 10:54:59 - 11:24:59 7050
CU-SBO 11:09:59 -4.5 CT Down 27.4 226.0 Low 10:54:59 - 11:24:59 7046
Bishop 11:10:37 -13.9 AT Down 35.9 214.1 Up 10:55:37 - 11:25:37 7003
Beatty 11:10:31 -13.3 AT Down 35.5 216.0 Up 10:55:31 - 11:25:31 6948
Patrick 11:10:19 -12.6 AT Down 35.3 219.6 Up 10:55:19 - 11:25:19 6795
Laughlin/Bullhead City 11:10:22 -13.2 AT Down 35.8 219.0 Up 10:55:22 - 11:25:22 6783
Wildwood 11:10:35 -16.4 AT Down 38.7 215.3 Up 10:55:35 - 11:25:35 6744
Lake Havasu City 11:10:19 -13.5 AT Down 36.2 219.6 Up 10:55:19 - 11:25:19 6725
Idyllwild 11:10:27 -15.5 AT Down 38.0 217.4 Up 10:55:27 - 11:25:27 6693
George/Scottsdale 11:10:10 -12.5 AT Down 35.5 222.4 Up 10:55:10 - 11:25:10 6629
Calipatria 11:10:23 -15.2 AT Down 37.9 219.0 Up 10:55:23 - 11:25:23 6626
Yuma 11:10:18 -14.9 AT Down 37.8 220.1 Up 10:55:18 - 11:25:18 6579

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 503858, (2026/06/24 11:00UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 47.20  37
Nunki          18:55:15.9 -26:17:50  2.0 18.93  70
37 Aql         19:35:07.3 -10:33:37  4.7  0.70  83
PPM 236244     19:36:50.7 -10:09:27  6.9  0.21  83
503858         19:37:38.2 -10:14:06 16.8        83
Positions are for J2000

Event circumstances last updated at 2023/09/03 03:45:47 UT

Marc W. Buie, Southwest Research Institute

RECON