RECON: TNO occultation with 98WS31

Event between 98WS31 and star GA1180:01984179 with event index number of 1238742

Geocentric closest approach at 2023/04/10 05:17:02 UTC

J2000 position of star is 05:57:14.6 +29:53:17
Equinox of date position of star is 05:58:43.1 +29:53:21
Stellar brightness G=16.7, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 160 degrees from the moon. Moon is 83% illuminated.
Apparent brightness V=23.7

[RECON map]
Object is 33.2 AU from the Sun and 33.5 AU from the Earth.
Apparent velocity is 15.7 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 408 seconds.
The 1-sigma cross-track error in the shadow position is 2578 km.
The sky-plane scale is 24331.0 km/arcsec.

The object has an absolute magnitude Hv=8.3
Diameter=134.3 km assuming a 5% albedo -- 8.6 sec chord
Diameter=54.8 km assuming a 30% albedo -- 3.5 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 

Star training set for 98WS31, (2023/04/10 04:57UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:56:25.9 +07:24:34  0.4 22.49 153
Alnath         05:27:45.9 +28:37:30  1.6  6.87 166
PPM 095117     05:58:02.5 +28:56:38  6.5  0.96 160
PPM 095161     05:59:53.3 +29:37:39  8.2  0.36 159
PPM 095148     05:59:20.1 +29:48:49 10.0  0.15 159
98WS31         05:58:44.0 +29:53:21 16.7       159
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 2.2 sigma about the mid-time.
The median site spacing is 11.4 km RECON observability=1.0 and success probability=1.3%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Sleaford 05:20:12 -26.0 Dark Down 27.3 284.5 Low 05:05:12 - 05:35:12 9277
Kamloops 05:20:08 -21.7 Dark Down 35.9 275.0 Up 05:05:08 - 05:35:08 8677
Dunrhomin 05:21:20 -36.6 Dark Down 23.0 290.5 Low 05:06:20 - 05:36:20 8664
Kelowna 05:20:16 -22.7 Dark Down 35.2 276.2 Up 05:05:16 - 05:35:16 8662
Nikitin 05:21:21 -36.7 Dark Down 22.9 290.6 Low 05:06:21 - 05:36:21 8652
CU-SBO 05:21:22 -36.8 Dark Down 23.0 290.5 Low 05:06:22 - 05:36:22 8645
Peachland 05:20:15 -22.7 Dark Down 35.4 276.1 Up 05:05:15 - 05:35:15 8644
Penticton 05:20:17 -22.9 Dark Down 35.2 276.4 Up 05:05:17 - 05:35:17 8639
Summerland 05:20:18 -22.8 Dark Down 35.3 276.3 Up 05:05:18 - 05:35:18 8639
Oliver 05:20:20 -23.2 Dark Down 35.2 276.7 Up 05:05:20 - 05:35:20 8618
Anarchist Mountain Observatory 05:20:21 -23.4 Dark Down 35.1 276.9 Up 05:05:21 - 05:35:21 8615
Okanogan 05:20:25 -23.8 Dark Down 35.1 277.2 Up 05:05:25 - 05:35:25 8566
Brewster 05:20:27 -23.9 Dark Down 35.2 277.3 Up 05:05:27 - 05:35:27 8542
Manson/Chelan 05:20:25 -23.9 Dark Down 35.4 277.2 Up 05:05:25 - 05:35:25 8514
Wenatchee 05:20:29 -24.1 Dark Down 35.5 277.4 Up 05:05:29 - 05:35:29 8477
PNWRO 05:20:39 -25.8 Dark Down 34.3 279.4 Up 05:05:39 - 05:35:39 8445
Ellensburg 05:20:31 -24.3 Dark Down 35.6 277.6 Up 05:05:31 - 05:35:31 8442
Victoria 05:20:18 -21.8 Dark Down 37.7 274.4 Up 05:05:18 - 05:35:18 8427
Yakima 05:20:34 -24.6 Dark Down 35.5 277.8 Up 05:05:34 - 05:35:34 8415
Toppenish/White Swan 05:20:34 -24.8 Dark Down 35.4 278.1 Up 05:05:34 - 05:35:34 8408
The Dalles 05:20:38 -25.0 Dark Down 35.8 278.2 Up 05:05:38 - 05:35:38 8324
Maupin 05:20:40 -25.3 Dark Down 35.6 278.5 Up 05:05:40 - 05:35:40 8301
Sisters 05:20:43 -25.7 Dark Down 35.8 278.9 Up 05:05:43 - 05:35:43 8221
Bend 05:20:45 -26.0 Dark Down 35.6 279.2 Up 05:05:45 - 05:35:45 8216
Oregon Observatory 05:20:48 -26.1 Dark Down 35.7 279.2 Up 05:05:48 - 05:35:48 8198
Cedarville 05:21:02 -28.4 Dark Down 34.3 281.6 Up 05:06:02 - 05:36:02 8090
Chiloquin 05:20:53 -26.7 Dark Down 35.7 279.9 Up 05:05:53 - 05:35:53 8089
Klamath Falls 05:20:55 -27.0 Dark Down 35.6 280.2 Up 05:05:55 - 05:35:55 8069
Fall River/Burney 05:21:03 -28.0 Dark Down 35.1 281.3 Up 05:06:03 - 05:36:03 8002
Reno 05:21:12 -30.0 Dark Down 33.6 283.2 Up 05:06:12 - 05:36:12 7965
Gimple 05:21:08 -28.9 Dark Down 34.5 282.2 Up 05:06:08 - 05:36:08 7960
Greenville 05:21:06 -28.9 Dark Down 34.6 282.2 Up 05:06:06 - 05:36:06 7956
Yerington 05:21:16 -30.7 Dark Down 32.9 283.9 Up 05:06:16 - 05:36:16 7955
Portola 05:21:10 -29.4 Dark Down 34.1 282.6 Up 05:06:10 - 05:36:10 7955
Hawthorne 05:21:20 -31.3 Dark Down 32.4 284.4 Up 05:06:20 - 05:36:20 7946
Patrick 05:21:40 -36.3 Dark Down 27.8 288.4 Low 05:06:40 - 05:36:40 7943
Quincy 05:21:08 -29.0 Dark Down 34.5 282.3 Up 05:06:08 - 05:36:08 7942
Carson City 05:21:14 -30.2 Dark Down 33.5 283.4 Up 05:06:14 - 05:36:14 7940
Gardnerville 05:21:15 -30.4 Dark Down 33.4 283.6 Up 05:06:15 - 05:36:15 7924
George/Scottsdale 05:21:50 -38.7 Dark Down 25.6 290.1 Low 05:06:50 - 05:36:50 7916
Beatty 05:21:30 -33.6 Dark Down 30.5 286.3 Up 05:06:30 - 05:36:30 7914
Laughlin/Bullhead City 05:21:40 -36.1 Dark Down 28.3 288.2 Low 05:06:40 - 05:36:40 7891
Lee Vining 05:21:22 -31.5 Dark Down 32.6 284.5 Up 05:06:22 - 05:36:22 7882
Bishop 05:21:26 -32.3 Dark Down 31.9 285.3 Up 05:06:26 - 05:36:26 7872
Lake Havasu City 05:21:44 -36.7 Dark Down 27.9 288.7 Low 05:06:44 - 05:36:44 7854
Yuma 05:21:53 -37.8 Dark Down 27.5 289.5 Low 05:06:53 - 05:36:53 7704
Calipatria 05:21:50 -37.0 Dark Down 28.3 288.9 Low 05:06:50 - 05:36:50 7693
Idyllwild 05:21:45 -35.8 Dark Down 29.5 288.1 Low 05:06:45 - 05:36:45 7682
Wildwood 05:21:40 -34.4 Dark Down 31.1 287.1 Up 05:06:40 - 05:36:40 7616

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 98WS31, (2023/04/10 04:57UT)
Object            RA         Dec     mag  sep  mel
Betelgeuse     05:55:10.3 +07:24:26  0.4 22.49 153
Alnath         05:26:17.5 +28:36:23  1.6  6.87 166
PPM 095117     05:56:33.8 +28:56:32  6.5  0.96 160
PPM 095161     05:58:24.1 +29:37:37  8.2  0.36 159
PPM 095148     05:57:50.7 +29:48:46 10.0  0.15 159
98WS31         05:57:14.6 +29:53:17 16.7       159
Positions are for J2000

Event circumstances last updated at 2023/01/10 03:23:00 UT

Marc W. Buie, Southwest Research Institute

RECON