RECON: TNO occultation with 278361

Event between (278361) 07JJ43 and star GA0640:16279575 with event index number of 2182145

Geocentric closest approach at 2025/06/06 09:49:35 UTC

J2000 position of star is 17:29:54.7 -25:20:11
Equinox of date position of star is 17:31:24.2 -25:21:13
Stellar brightness G=15.6, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 61 degrees from the moon. Moon is 79% illuminated.
Apparent brightness V=20.6

[RECON map]
Object is 40.6 AU from the Sun and 39.6 AU from the Earth.
Apparent velocity is 24.2 km/sec on the sky relative to the star, or, 3.0 arcsec/hr.
The 1-sigma error in the time of the event is 305 seconds.
The 1-sigma cross-track error in the shadow position is 1855 km.
The sky-plane scale is 28709.1 km/arcsec.

The object has an absolute magnitude Hv=4.5
Diameter=758.6 km assuming a 5% albedo -- 31.5 sec chord
Diameter=309.7 km assuming a 30% albedo -- 12.9 sec chord
Dynamical classification is SCATNEAR
 
 
 
 
 
 

Star training set for 278361, (2025/06/06 09:50UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:58.2 -26:29:10  0.9 13.64  48
35Eta Oph      17:11:50.3 -15:45:16  2.6 10.64  57
PPM 266967     17:33:19.2 -26:17:12  6.3  1.02  62
PPM 266914     17:30:13.1 -25:31:47  7.4  0.33  61
278361         17:31:28.8 -25:21:16 15.6        62
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 3.0 sigma about the mid-time.
The median site spacing is 16.9 km RECON observability=0.5 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 09:49:02 -12.8 AT Down 12.1 198.0 Really Low 09:34:02 - 10:04:02 12670
Kelowna 09:48:58 -13.3 AT Down 12.7 198.8 Really Low 09:33:58 - 10:03:58 12644
Peachland 09:48:58 -13.5 AT Down 12.8 198.5 Really Low 09:33:58 - 10:03:58 12642
Summerland 09:48:59 -13.6 AT Down 12.9 198.6 Really Low 09:33:59 - 10:03:59 12638
Penticton 09:48:58 -13.6 AT Down 13.0 198.7 Really Low 09:33:58 - 10:03:58 12635
Oliver 09:48:58 -13.9 AT Down 13.3 198.8 Really Low 09:33:58 - 10:03:58 12625
Anarchist Mountain Observatory 09:48:57 -14.0 AT Down 13.4 199.0 Really Low 09:33:57 - 10:03:57 12620
Victoria 09:49:08 -15.6 AT Down 14.7 195.3 Really Low 09:34:08 - 10:04:08 12619
Okanogan 09:48:57 -14.7 AT Down 14.1 198.8 Really Low 09:33:57 - 10:03:57 12601
Sleaford 09:48:28 -6.9 NT Down 7.1 210.4 Really Low 09:33:28 - 10:03:28 12596
Brewster 09:48:57 -15.0 AT Down 14.4 198.6 Really Low 09:33:57 - 10:03:57 12593
Manson/Chelan 09:48:58 -15.2 AT Down 14.7 198.3 Really Low 09:33:58 - 10:03:58 12588
Wenatchee 09:48:58 -15.7 AT Down 15.2 198.2 Really Low 09:33:58 - 10:03:58 12574
Ellensburg 09:48:58 -16.2 AT Down 15.6 198.0 Really Low 09:33:58 - 10:03:58 12561
Yakima 09:48:57 -16.5 AT Down 16.0 198.1 Really Low 09:33:57 - 10:03:57 12548
Toppenish/White Swan 09:48:56 -16.7 AT Down 16.2 198.2 Really Low 09:33:56 - 10:03:56 12539
PNWRO 09:48:51 -16.5 AT Down 16.2 199.6 Really Low 09:33:51 - 10:03:51 12520
The Dalles 09:48:58 -17.6 AT Down 17.1 197.6 Really Low 09:33:58 - 10:03:58 12515
Maupin 09:48:58 -18.0 AT Down 17.4 197.7 Really Low 09:33:58 - 10:03:58 12500
Sisters 09:48:58 -18.9 Dark Down 18.4 197.4 Really Low 09:33:58 - 10:03:58 12470
Bend 09:48:57 -19.0 Dark Down 18.6 197.6 Really Low 09:33:57 - 10:03:57 12460
Oregon Observatory 09:48:57 -19.2 Dark Down 18.8 197.5 Really Low 09:33:57 - 10:03:57 12454
Chiloquin 09:48:56 -20.6 Dark Down 20.1 197.3 Low 09:33:56 - 10:03:56 12403
Klamath Falls 09:48:57 -20.8 Dark Down 20.4 197.4 Low 09:33:57 - 10:03:57 12388
Cedarville 09:48:50 -21.0 Dark Down 20.7 198.9 Low 09:33:50 - 10:03:50 12352
Fall River/Burney 09:48:54 -21.8 Dark Down 21.5 197.9 Low 09:33:54 - 10:03:54 12336
Greenville 09:48:51 -22.5 Dark Down 22.2 198.4 Low 09:33:51 - 10:03:51 12294
Gimple 09:48:51 -22.4 Dark Down 22.2 198.5 Low 09:33:51 - 10:03:51 12293
Quincy 09:48:51 -22.6 Dark Down 22.4 198.4 Low 09:33:51 - 10:03:51 12284
Portola 09:48:50 -22.6 Dark Down 22.4 198.9 Low 09:33:50 - 10:03:50 12277
Reno 09:48:46 -22.6 Dark Down 22.5 199.5 Low 09:33:46 - 10:03:46 12261
Carson City 09:48:46 -22.9 Dark Down 22.8 199.6 Low 09:33:46 - 10:03:46 12244
Gardnerville 09:48:47 -23.1 Dark Down 23.0 199.7 Low 09:33:47 - 10:03:47 12232
Yerington 09:48:44 -22.8 Dark Down 22.8 200.2 Low 09:33:44 - 10:03:44 12231
Hawthorne 09:48:42 -23.1 Dark Down 23.1 200.8 Low 09:33:42 - 10:03:42 12206
Lee Vining 09:48:43 -23.7 Dark Down 23.8 200.4 Low 09:33:43 - 10:03:43 12182
Dunrhomin 09:48:02 -15.8 AT Down 17.0 212.3 Really Low 09:33:02 - 10:03:02 12152
Bishop 09:48:40 -24.0 Dark Down 24.2 201.1 Low 09:33:40 - 10:03:40 12147
Nikitin 09:48:02 -16.0 AT Down 17.2 212.3 Really Low 09:33:02 - 10:03:02 12143
CU-SBO 09:48:02 -16.1 AT Down 17.3 212.3 Really Low 09:33:02 - 10:03:02 12141
Beatty 09:48:33 -23.7 Dark Down 24.1 202.7 Low 09:33:33 - 10:03:33 12112
Patrick 09:48:22 -23.8 Dark Down 24.5 205.6 Low 09:33:22 - 10:03:22 12009
Laughlin/Bullhead City 09:48:24 -24.3 Dark Down 25.0 205.0 Low 09:33:24 - 10:03:24 12001
Wildwood 09:48:36 -26.9 Dark Down 27.3 201.5 Low 09:33:36 - 10:03:36 11973
Lake Havasu City 09:48:22 -24.7 Dark Down 25.5 205.4 Low 09:33:22 - 10:03:22 11962
Idyllwild 09:48:29 -26.4 Dark Down 27.0 203.4 Low 09:33:29 - 10:03:29 11941
Calipatria 09:48:25 -26.4 Dark Down 27.2 204.6 Low 09:33:25 - 10:03:25 11895
George/Scottsdale 09:48:14 -24.2 Dark Down 25.3 207.8 Low 09:33:14 - 10:03:14 11893
Yuma 09:48:21 -26.4 Dark Down 27.3 205.5 Low 09:33:21 - 10:03:21 11862

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 278361, (2025/06/06 09:50UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 13.64  48
35Eta Oph      17:10:22.8 -15:43:28  2.6 10.64  57
PPM 266967     17:31:44.4 -26:16:12  6.3  1.02  62
PPM 266914     17:28:38.8 -25:30:39  7.4  0.33  61
278361         17:29:54.7 -25:20:11 15.6        61
Positions are for J2000

Event circumstances last updated at 2024/03/02 06:16:10 UT

Marc W. Buie, Southwest Research Institute

RECON