RECON: TNO occultation with 5145

Event between (5145) Pholus and star GA0740:21742945 with event index number of 1545804

Geocentric closest approach at 2026/08/28 06:25:04 UTC

J2000 position of star is 18:39:49.6 -14:49:56
Equinox of date position of star is 18:41:13.3 -14:48:30
Stellar brightness G=17.0, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 57 degrees from the moon. Moon is 100% illuminated.
Apparent brightness V=22.1

[RECON map]
Object is 30.6 AU from the Sun and 30.1 AU from the Earth.
Apparent velocity is 14.2 km/sec on the sky relative to the star, or, 2.3 arcsec/hr.
The 1-sigma error in the time of the event is 209 seconds.
The 1-sigma cross-track error in the shadow position is 1644 km.
The sky-plane scale is 21794.8 km/arcsec.

The object has an absolute magnitude Hv=7.1
Diameter=229.1 km assuming a 5% albedo -- 16.4 sec chord
Diameter=93.5 km assuming a 30% albedo -- 6.7 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 

Star training set for 5145, (2026/08/28 06:25UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:02.8 -26:29:20  0.9 32.52  86
Nunki          18:56:55.0 -26:15:40  2.0 12.02  54
PPM 234707     18:35:10.4 -14:49:54  6.1  1.49  58
PPM 234839     18:40:33.9 -15:00:49  7.4  0.28  57
PPM 234868     18:41:50.2 -14:43:56  9.3  0.14  56
5145           18:41:20.8 -14:48:22 17.0        56
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 4.3 sigma about the mid-time.
The median site spacing is 27.0 km RECON observability=0.9 and success probability=34.4%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Kamloops 06:20:06 -25.7 Dark Up 19.0 212.0 Really Low 06:05:06 - 06:35:06 564
Victoria 06:20:15 -26.5 Dark Up 21.9 209.5 Low 06:05:15 - 06:35:15 531
Peachland 06:20:03 -26.6 Dark Up 19.6 212.7 Really Low 06:05:03 - 06:35:03 485
Kelowna 06:20:02 -26.6 Dark Up 19.4 213.0 Really Low 06:05:02 - 06:35:02 482
Summerland 06:20:03 -26.8 Dark Up 19.7 212.8 Really Low 06:05:03 - 06:35:03 472
Penticton 06:20:03 -26.9 Dark Up 19.7 213.0 Really Low 06:05:03 - 06:35:03 464
Oliver 06:20:02 -27.2 Dark Up 20.0 213.0 Low 06:05:02 - 06:35:02 441
Anarchist Mountain Observatory 06:20:00 -27.4 Dark Up 20.1 213.2 Low 06:05:00 - 06:35:00 424
Okanogan 06:20:00 -27.9 Dark Up 20.7 213.2 Low 06:05:00 - 06:35:00 388
Brewster 06:20:01 -28.1 Dark Up 21.0 213.0 Low 06:05:01 - 06:35:01 377
Manson/Chelan 06:20:02 -28.2 Dark Up 21.3 212.7 Low 06:05:02 - 06:35:02 376
Wenatchee 06:20:02 -28.5 Dark Up 21.8 212.6 Low 06:05:02 - 06:35:02 350
Ellensburg 06:20:03 -28.8 Dark Up 22.2 212.5 Low 06:05:03 - 06:35:03 331
Yakima 06:20:02 -29.2 Dark Up 22.6 212.6 Low 06:05:02 - 06:35:02 304
Toppenish/White Swan 06:20:02 -29.4 Dark Up 22.7 212.8 Low 06:05:02 - 06:35:02 283
The Dalles 06:20:04 -29.8 Dark Up 23.6 212.2 Low 06:05:04 - 06:35:04 258
Maupin 06:20:03 -30.2 Dark Up 23.9 212.4 Low 06:05:03 - 06:35:03 225
PNWRO 06:19:55 -30.2 Dark Up 22.4 214.3 Low 06:04:55 - 06:34:55 203
Sleaford 06:19:23 -27.5 Dark Up 12.4 224.9 Really Low 06:04:23 - 06:34:23 194
Sisters 06:20:04 -30.8 Dark Up 24.9 212.2 Low 06:05:04 - 06:35:04 183
Bend 06:20:03 -31.1 Dark Up 25.0 212.5 Low 06:05:03 - 06:35:03 156
Oregon Observatory 06:20:04 -31.2 Dark Up 25.2 212.4 Low 06:05:04 - 06:35:04 149
Chiloquin 06:20:04 -32.1 Dark Up 26.4 212.3 Low 06:05:04 - 06:35:04 71
Klamath Falls 06:20:04 -32.5 Dark Up 26.7 212.5 Low 06:05:04 - 06:35:04 43
Fall River/Burney 06:20:01 -33.6 Dark Up 27.5 213.2 Low 06:05:01 - 06:35:01 -58
Cedarville 06:19:57 -33.7 Dark Up 26.6 214.2 Low 06:04:57 - 06:34:57 -70
Greenville 06:19:59 -34.6 Dark Up 28.1 213.9 Low 06:04:59 - 06:34:59 -143
Gimple 06:19:59 -34.6 Dark Up 28.1 214.0 Low 06:04:59 - 06:34:59 -147
Quincy 06:19:59 -34.7 Dark Up 28.3 214.0 Low 06:04:59 - 06:34:59 -159
Portola 06:19:57 -35.0 Dark Up 28.2 214.5 Low 06:04:57 - 06:34:57 -187
Reno 06:19:54 -35.5 Dark Up 28.1 215.2 Low 06:04:54 - 06:34:54 -233
Carson City 06:19:54 -35.8 Dark Up 28.4 215.3 Low 06:04:54 - 06:34:54 -262
Gardnerville 06:19:54 -36.1 Dark Up 28.6 215.4 Low 06:04:54 - 06:34:54 -282
Yerington 06:19:51 -36.2 Dark Up 28.3 216.0 Low 06:04:51 - 06:34:51 -302
Hawthorne 06:19:49 -36.8 Dark Up 28.4 216.6 Low 06:04:49 - 06:34:49 -360
Lee Vining 06:19:50 -37.1 Dark Up 29.1 216.3 Low 06:04:50 - 06:34:50 -384
Bishop 06:19:47 -37.9 Dark Up 29.2 217.2 Low 06:04:47 - 06:34:47 -461
Beatty 06:19:40 -39.0 Dark Up 28.8 218.9 Low 06:04:40 - 06:34:40 -566
Wildwood 06:19:47 -40.7 Dark Up 31.9 218.2 Up 06:04:47 - 06:34:47 -718
Dunrhomin 06:18:58 -39.1 Dark Up 20.2 227.9 Low 06:03:58 - 06:33:58 -753
Nikitin 06:18:58 -39.3 Dark Up 20.4 228.0 Low 06:03:58 - 06:33:58 -767
CU-SBO 06:18:58 -39.3 Dark Up 20.5 227.9 Low 06:03:58 - 06:33:58 -770
Laughlin/Bullhead City 06:19:29 -41.3 Dark Up 29.0 221.5 Low 06:04:29 - 06:34:29 -800
Patrick 06:19:27 -41.3 Dark Up 28.5 222.1 Low 06:04:27 - 06:34:27 -809
Idyllwild 06:19:40 -41.8 Dark Up 31.2 220.1 Up 06:04:40 - 06:34:40 -828
Lake Havasu City 06:19:28 -42.0 Dark Up 29.4 222.0 Low 06:04:28 - 06:34:28 -867
Calipatria 06:19:33 -42.8 Dark Up 31.1 221.4 Up 06:04:33 - 06:34:33 -931
Yuma 06:19:29 -43.5 Dark Up 30.9 222.4 Up 06:04:29 - 06:34:29 -1007
George/Scottsdale 06:19:18 -43.6 Dark Up 28.6 224.5 Low 06:04:18 - 06:34:18 -1038

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 5145, (2026/08/28 06:25UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 32.52  86
Nunki          18:55:15.9 -26:17:49  2.0 12.02  54
PPM 234707     18:33:39.1 -14:51:14  6.1  1.49  58
PPM 234839     18:39:02.5 -15:02:21  7.4  0.28  57
PPM 234868     18:40:19.0 -14:45:31  9.3  0.14  56
5145           18:39:49.6 -14:49:56 17.0        57
Positions are for J2000

Event circumstances last updated at 2024/06/19 21:32:40 UT

Marc W. Buie, Southwest Research Institute

RECON