RECON: TNO occultation with 181855

Event between (181855) 98WT31 and star GA1360:03585552 with event index number of 2664197

Geocentric closest approach at 2029/01/09 04:20:56 UTC

J2000 position of star is 06:03:15.9 +46:35:14
Equinox of date position of star is 06:05:05.5 +46:35:05
Stellar brightness G=14.5, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 128 degrees from the moon. Moon is 32% illuminated.
Apparent brightness V=23.5

[RECON map]
Object is 37.7 AU from the Sun and 36.9 AU from the Earth.
Apparent velocity is 23.9 km/sec on the sky relative to the star, or, 3.2 arcsec/hr.
The 1-sigma error in the time of the event is 675 seconds.
The 1-sigma cross-track error in the shadow position is 5615 km.
The sky-plane scale is 26729.1 km/arcsec.

The object has an absolute magnitude Hv=7.7
Diameter=173.8 km assuming a 5% albedo -- 7.3 sec chord
Diameter=70.9 km assuming a 30% albedo -- 3.0 sec chord
Dynamical classification is SCATEXTD
 
 
 
 
 
 

Star training set for 181855, (2029/01/09 04:21UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:47:05.6 +27:57:13  1.1 27.27 108
34Bet Aur      06:01:39.6 +44:56:49  1.9  1.76 129
35Pi Aur       06:02:05.4 +45:56:09  5.9  0.87 129
PPM 048675     06:04:39.2 +46:38:31  8.2  0.15 128
PPM 048691     06:05:22.6 +46:37:53  9.1  0.05 128
181855         06:05:26.1 +46:35:03 14.5       128
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 1.3 sigma about the mid-time.
The median site spacing is 33.2 km RECON observability=1.0 and success probability=9.3%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Kamloops 04:22:34 -37.9 Dark Down 65.8 85.4 Up 04:07:34 - 04:37:34 -2446
Victoria 04:22:47 -36.4 Dark Down 63.5 79.1 Up 04:07:47 - 04:37:47 -2537
Kelowna 04:22:34 -38.7 Dark Down 66.3 84.1 Up 04:07:34 - 04:37:34 -2555
Peachland 04:22:35 -38.5 Dark Down 66.1 83.7 Up 04:07:35 - 04:37:35 -2555
Summerland 04:22:35 -38.6 Dark Down 66.1 83.4 Up 04:07:35 - 04:37:35 -2572
Penticton 04:22:35 -38.7 Dark Down 66.2 83.3 Up 04:07:35 - 04:37:35 -2583
Oliver 04:22:36 -38.7 Dark Down 66.1 82.5 Up 04:07:36 - 04:37:36 -2616
Anarchist Mountain Observatory 04:22:36 -38.9 Dark Down 66.2 82.3 Up 04:07:36 - 04:37:36 -2639
Okanogan 04:22:38 -38.9 Dark Down 66.0 80.7 Up 04:07:38 - 04:37:38 -2693
Brewster 04:22:39 -38.8 Dark Down 65.8 80.0 Up 04:07:39 - 04:37:39 -2712
Manson/Chelan 04:22:41 -38.6 Dark Down 65.5 79.4 Up 04:07:41 - 04:37:41 -2719
Sleaford 04:21:57 -45.9 Dark Down 74.6 102.0 Up 04:06:57 - 04:36:57 -2730
Wenatchee 04:22:42 -38.6 Dark Down 65.3 78.3 Up 04:07:42 - 04:37:42 -2758
Ellensburg 04:22:44 -38.5 Dark Down 65.1 77.3 Up 04:07:44 - 04:37:44 -2789
Yakima 04:22:45 -38.5 Dark Down 65.0 76.5 Up 04:07:45 - 04:37:45 -2827
Toppenish/White Swan 04:22:44 -38.7 Dark Down 65.1 76.1 Up 04:07:44 - 04:37:44 -2854
The Dalles 04:22:49 -38.2 Dark Down 64.4 74.2 Up 04:07:49 - 04:37:49 -2898
Maupin 04:22:49 -38.4 Dark Down 64.3 73.4 Up 04:07:49 - 04:37:49 -2943
PNWRO 04:22:41 -39.8 Dark Down 66.0 75.8 Up 04:07:41 - 04:37:41 -2946
Sisters 04:22:52 -38.1 Dark Down 63.7 71.6 Up 04:07:52 - 04:37:52 -3007
Bend 04:22:52 -38.3 Dark Down 63.8 71.2 Up 04:07:52 - 04:37:52 -3040
Oregon Observatory 04:22:53 -38.3 Dark Down 63.7 70.8 Up 04:07:53 - 04:37:53 -3052
Chiloquin 04:22:57 -38.1 Dark Down 62.9 68.3 Up 04:07:57 - 04:37:57 -3161
Klamath Falls 04:22:57 -38.2 Dark Down 62.9 67.7 Up 04:07:57 - 04:37:57 -3197
Fall River/Burney 04:22:59 -38.5 Dark Down 62.7 65.6 Up 04:07:59 - 04:37:59 -3326
Cedarville 04:22:54 -39.4 Dark Down 63.7 66.5 Up 04:07:54 - 04:37:54 -3330
Greenville 04:23:00 -38.9 Dark Down 62.6 64.0 Up 04:08:00 - 04:38:00 -3432
Gimple 04:22:59 -39.0 Dark Down 62.6 64.0 Up 04:07:59 - 04:37:59 -3436
Quincy 04:23:00 -38.9 Dark Down 62.5 63.7 Up 04:08:00 - 04:38:00 -3452
Portola 04:22:59 -39.3 Dark Down 62.8 63.4 Up 04:07:59 - 04:37:59 -3484
Reno 04:22:58 -39.8 Dark Down 63.1 63.0 Up 04:07:58 - 04:37:58 -3537
Carson City 04:22:58 -39.9 Dark Down 63.0 62.3 Up 04:07:58 - 04:37:58 -3573
Gardnerville 04:22:59 -39.9 Dark Down 62.9 61.9 Up 04:07:59 - 04:37:59 -3598
Yerington 04:22:57 -40.3 Dark Down 63.3 61.9 Up 04:07:57 - 04:37:57 -3618
Hawthorne 04:22:56 -40.8 Dark Down 63.4 61.1 Up 04:07:56 - 04:37:56 -3685
Lee Vining 04:22:59 -40.4 Dark Down 62.8 60.2 Up 04:07:59 - 04:37:59 -3720
Bishop 04:22:58 -41.0 Dark Down 63.0 59.0 Up 04:07:58 - 04:37:58 -3809
Beatty 04:22:54 -42.3 Dark Down 63.9 57.9 Up 04:07:54 - 04:37:54 -3922
Dunrhomin 04:22:06 -50.6 Dark Down 73.2 60.7 Up 04:07:06 - 04:37:06 -3986
Nikitin 04:22:06 -50.7 Dark Down 73.1 60.2 Up 04:07:06 - 04:37:06 -4005
CU-SBO 04:22:06 -50.6 Dark Down 73.1 60.0 Up 04:07:06 - 04:37:06 -4010
Wildwood 04:23:04 -40.9 Dark Down 61.1 53.9 Up 04:08:04 - 04:38:04 -4119
Laughlin/Bullhead City 04:22:50 -44.2 Dark Down 64.4 54.1 Up 04:07:50 - 04:37:50 -4181
Patrick 04:22:48 -44.7 Dark Down 65.0 54.3 Up 04:07:48 - 04:37:48 -4185
Idyllwild 04:22:59 -42.5 Dark Down 62.1 52.7 Up 04:07:59 - 04:37:59 -4236
Lake Havasu City 04:22:51 -44.4 Dark Down 64.1 52.9 Up 04:07:51 - 04:37:51 -4258
Calipatria 04:22:57 -43.5 Dark Down 62.5 51.3 Up 04:07:57 - 04:37:57 -4345
Yuma 04:22:55 -44.2 Dark Down 62.8 50.2 Up 04:07:55 - 04:37:55 -4425
George/Scottsdale 04:22:44 -46.5 Dark Down 65.2 50.3 Up 04:07:44 - 04:37:44 -4432

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 181855, (2029/01/09 04:21UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:45:17.9 +28:01:33  1.1 27.27 108
34Bet Aur      05:59:31.6 +44:56:51  1.9  1.76 129
35Pi Aur       05:59:56.1 +45:56:12  5.9  0.87 129
PPM 048675     06:02:28.9 +46:38:40  8.2  0.15 128
PPM 048691     06:03:12.3 +46:38:03  9.1  0.05 128
181855         06:03:15.9 +46:35:14 14.5       128
Positions are for J2000

Event circumstances last updated at 2024/06/10 02:02:57 UT

Marc W. Buie, Southwest Research Institute

RECON