RECON: TNO occultation with 5145

Event between (5145) Pholus and star GA0740:20726623 with event index number of 1492880

Geocentric closest approach at 2025/08/01 05:02:07 UTC

J2000 position of star is 18:36:15.5 -14:10:48
Equinox of date position of star is 18:37:38.9 -14:09:29
Stellar brightness G=16.2, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 64 degrees from the moon. Moon is 47% illuminated.
Apparent brightness V=22.0

[RECON map]
Object is 30.4 AU from the Sun and 29.5 AU from the Earth.
Apparent velocity is 22.3 km/sec on the sky relative to the star, or, 3.7 arcsec/hr.
The 1-sigma error in the time of the event is 124 seconds.
The 1-sigma cross-track error in the shadow position is 1660 km.
The sky-plane scale is 21386.8 km/arcsec.

The object has an absolute magnitude Hv=7.1
Diameter=229.1 km assuming a 5% albedo -- 10.4 sec chord
Diameter=93.5 km assuming a 30% albedo -- 4.3 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 

Star training set for 5145, (2025/08/01 05:02UT)
Object            RA         Dec     mag  sep  mel
Antares        16:30:58.8 -26:29:11  0.9 32.05  34
Nunki          18:56:51.0 -26:15:45  2.0 12.91  66
PPM 234707     18:35:06.7 -14:49:57  6.1  0.92  63
PPM 234768     18:37:39.3 -13:48:39  8.3  0.35  64
5145           18:37:42.7 -14:09:26 16.2        65
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 5.0 sigma about the mid-time.
The median site spacing is 22.1 km RECON observability=0.6 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 05:01:51 -10.2 NT Up 24.0 165.2 Low 04:51:01 - 05:12:41 10260
Kelowna 05:01:49 -11.2 NT Up 24.9 166.1 Low 04:50:59 - 05:12:39 10214
Peachland 05:01:49 -11.1 NT Up 25.0 165.7 Low 04:50:59 - 05:12:39 10213
Summerland 05:01:49 -11.3 NT Up 25.2 165.8 Low 04:50:59 - 05:12:39 10206
Penticton 05:01:49 -11.3 NT Up 25.2 165.9 Low 04:50:59 - 05:12:39 10201
Victoria 05:02:03 -10.3 NT Up 25.5 161.8 Low 04:51:13 - 05:12:53 10201
Oliver 05:01:49 -11.6 NT Up 25.6 165.9 Low 04:50:59 - 05:12:39 10186
Anarchist Mountain Observatory 05:01:50 -11.8 NT Up 25.8 166.1 Low 04:51:00 - 05:12:40 10176
Okanogan 05:01:51 -12.2 AT Up 26.4 165.8 Low 04:51:01 - 05:12:41 10149
Brewster 05:01:52 -12.3 AT Up 26.6 165.5 Low 04:51:02 - 05:12:42 10139
Manson/Chelan 05:01:54 -12.3 AT Up 26.7 165.1 Low 04:51:04 - 05:12:44 10134
Sleaford 05:01:07 -14.6 AT Down 23.7 180.4 Low 04:50:17 - 05:11:57 10121
Wenatchee 05:01:55 -12.5 AT Up 27.2 164.9 Low 04:51:05 - 05:12:45 10114
Ellensburg 05:01:57 -12.7 AT Up 27.5 164.6 Low 04:51:07 - 05:12:47 10097
Yakima 05:01:57 -13.0 AT Up 27.9 164.5 Low 04:51:07 - 05:12:47 10077
Toppenish/White Swan 05:01:56 -13.2 AT Up 28.2 164.7 Low 04:51:06 - 05:12:46 10064
The Dalles 05:02:00 -13.4 AT Up 28.8 163.7 Low 04:51:10 - 05:12:50 10035
PNWRO 05:01:52 -14.2 AT Up 28.8 166.2 Low 04:51:02 - 05:12:42 10027
Maupin 05:02:00 -13.7 AT Up 29.2 163.8 Low 04:51:10 - 05:12:50 10013
Sisters 05:02:04 -14.1 AT Up 29.9 163.1 Low 04:51:14 - 05:12:54 9974
Bend 05:02:03 -14.4 AT Up 30.2 163.3 Up 04:51:13 - 05:12:53 9958
Oregon Observatory 05:02:03 -14.4 AT Up 30.4 163.2 Up 04:51:13 - 05:12:53 9951
Chiloquin 05:02:07 -15.1 AT Up 31.5 162.5 Up 04:51:17 - 05:12:57 9885
Klamath Falls 05:02:07 -15.4 AT Up 31.9 162.5 Up 04:51:17 - 05:12:57 9865
Cedarville 05:02:02 -16.7 AT Up 32.9 164.2 Up 04:51:12 - 05:12:52 9804
Fall River/Burney 05:02:08 -16.4 AT Up 33.1 162.7 Up 04:51:18 - 05:12:58 9793
Greenville 05:02:07 -17.3 AT Up 34.0 163.1 Up 04:51:17 - 05:12:57 9733
Gimple 05:02:07 -17.3 AT Up 34.1 163.2 Up 04:51:17 - 05:12:57 9732
Quincy 05:02:08 -17.4 AT Up 34.2 163.0 Up 04:51:18 - 05:12:58 9721
Portola 05:02:06 -17.8 AT Up 34.5 163.5 Up 04:51:16 - 05:12:56 9707
Reno 05:02:04 -18.3 Dark Up 34.9 164.2 Up 04:51:14 - 05:12:54 9682
Carson City 05:02:05 -18.6 Dark Up 35.2 164.2 Up 04:51:15 - 05:12:55 9660
Gardnerville 05:02:05 -18.8 Dark Up 35.5 164.2 Up 04:51:15 - 05:12:55 9644
Yerington 05:02:02 -19.1 Dark Up 35.5 164.9 Up 04:51:12 - 05:12:52 9638
Hawthorne 05:02:01 -19.7 Dark Up 36.1 165.4 Up 04:51:11 - 05:12:51 9602
Lee Vining 05:02:04 -19.8 Dark Up 36.5 164.7 Up 04:51:14 - 05:12:54 9574
Bishop 05:02:03 -20.6 Dark Up 37.3 165.5 Up 04:51:13 - 05:12:53 9524
Dunrhomin 05:01:10 -24.8 Dark Up 35.6 181.3 Up 04:50:20 - 05:12:00 9474
Beatty 05:01:57 -21.9 Dark Up 38.0 167.3 Up 04:51:07 - 05:12:47 9468
Nikitin 05:01:11 -25.0 Dark Up 35.7 181.3 Up 04:50:21 - 05:12:01 9463
CU-SBO 05:01:11 -25.0 Dark Up 35.8 181.2 Up 04:50:21 - 05:12:01 9460
Patrick 05:01:48 -24.5 Dark Up 39.9 170.6 Up 04:50:58 - 05:12:38 9320
Laughlin/Bullhead City 05:01:50 -24.3 Dark Up 40.1 169.7 Up 04:51:00 - 05:12:40 9315
Wildwood 05:02:07 -22.8 Dark Up 40.4 164.6 Up 04:51:17 - 05:12:57 9309
Lake Havasu City 05:01:49 -25.0 Dark Up 40.8 169.9 Up 04:50:59 - 05:12:39 9264
Idyllwild 05:02:00 -24.2 Dark Up 41.1 166.8 Up 04:51:10 - 05:12:50 9254
Calipatria 05:01:57 -25.3 Dark Up 41.9 168.2 Up 04:51:07 - 05:12:47 9189
George/Scottsdale 05:01:41 -26.9 Dark Up 41.8 172.9 Up 04:50:51 - 05:12:31 9165
Yuma 05:01:54 -26.1 Dark Up 42.5 169.3 Up 04:51:04 - 05:12:44 9142

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, (2025/08/01 05:02UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 32.05  34
Nunki          18:55:15.9 -26:17:49  2.0 12.91  66
PPM 234707     18:33:39.1 -14:51:14  6.1  0.92  63
PPM 234768     18:36:12.4 -13:50:02  8.3  0.35  64
5145           18:36:15.5 -14:10:48 16.2        64
Positions are for J2000

Event circumstances last updated at 2024/06/18 02:51:50 UT

Marc W. Buie, Southwest Research Institute

RECON