RECON: TNO occultation with 04HX78

Event between 04HX78 and star GA0780:10946460 with event index number of 1449424

Geocentric closest approach at 2026/05/21 09:01:27 UTC

J2000 position of star is 18:24:28.2 -11:07:40
Equinox of date position of star is 18:25:35.8 -11:06:56
Stellar brightness G=14.4, use SENSEUP=128
Star is 149 degrees from the moon. Moon is 28% illuminated.
TNO apparent brightness V=25.4

[RECON map]
TNO is 33.9 AU from the Sun and 33.1 AU from the Earth.
The TNO is moving 18.8 km/sec on the sky relative to the star, or, 2.8 arcsec/hr.
The 1-sigma error in the time of the event is 541 seconds.
The 1-sigma cross-track error in the shadow position is 3170 km.
The sky-plane scale is 24010.7 km/arcsec.

The TNO has an absolute magnitude Hv=10.0
Diameter=140.0 km assuming a 5% albedo -- 3.2 sec chord
Diameter=57.1 km assuming a 30% albedo -- 1.3 sec chord
Dynamical classification is 3:2E
 
 
 
 
 
 

Star training set for 04HX78, (2026/05/21 09:01UT)
Object            RA         Dec     mag  sep  mel
Antares        16:31:01.8 -26:29:17  0.9 31.12 126
Nunki          18:56:54.0 -26:15:41  2.0 16.82 159
PPM 234462     18:24:40.8 -11:59:58  6.3  0.94 149
PPM 234491     18:25:57.2 -10:23:55  8.1  0.71 149
PPM 234486     18:25:42.6 -11:13:34  9.1  0.13 149
04HX78         18:25:56.2 -11:06:42 14.4       149
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 1.7 sigma about the mid-time.
The median site spacing is 15.6 km RECON observability=1.0 and success probability=4.1%
Site Site mid-time
(UT)
Sun alt
(deg)
Sky Moon Star alt
(deg)
Star az
(deg)
Target Observing Time
(UT)
X-track
(km)
Clarence Fulton 09:03:43 -17.9 AT Down 26.1 157.5 Low 08:48:43 - 09:18:43 6632
Kelowna 09:03:43 -18.3 Dark Down 26.4 157.3 Low 08:48:43 - 09:18:43 6606
Peachland 09:03:44 -18.4 Dark Down 26.4 157.0 Low 08:48:44 - 09:18:44 6594
Summerland 09:03:44 -18.5 Dark Down 26.6 157.0 Low 08:48:44 - 09:18:44 6586
Penticton 09:03:43 -18.6 Dark Down 26.7 157.1 Low 08:48:43 - 09:18:43 6584
Oliver 09:03:45 -18.9 Dark Down 27.0 157.1 Low 08:48:45 - 09:18:45 6563
Anarchist Mountain Observatory 09:03:44 -19.0 Dark Down 27.2 157.2 Low 08:48:44 - 09:18:44 6557
Tonasket 09:03:43 -19.4 Dark Down 27.5 157.1 Low 08:48:43 - 09:18:43 6536
Okanogan 09:03:45 -19.7 Dark Down 27.7 156.9 Low 08:48:45 - 09:18:45 6512
Brewster 09:03:46 -20.0 Dark Down 27.9 156.6 Low 08:48:46 - 09:18:46 6491
Manson/Chelan 09:03:47 -20.3 Dark Down 28.0 156.2 Low 08:48:47 - 09:18:47 6471
Entiat 09:03:47 -20.5 Dark Down 28.2 156.1 Low 08:48:47 - 09:18:47 6455
Victoria 09:03:58 -20.2 Dark Down 26.5 152.9 Low 08:48:58 - 09:18:58 6448
Wenatchee 09:03:48 -20.8 Dark Down 28.4 155.9 Low 08:48:48 - 09:18:48 6437
Ellensburg 09:03:49 -21.2 Dark Down 28.7 155.6 Low 08:48:49 - 09:18:49 6406
Pasco 09:03:45 -21.6 Dark Down 29.8 156.9 Low 08:48:45 - 09:18:45 6386
Yakima 09:03:50 -21.6 Dark Down 29.1 155.5 Low 08:48:50 - 09:18:50 6379
PNWRO 09:03:44 -21.8 Dark Down 30.1 157.1 Up 08:48:44 - 09:18:44 6374
Toppenish/White Swan 09:03:50 -21.8 Dark Down 29.3 155.6 Low 08:48:50 - 09:18:50 6369
Goldendale 09:03:51 -22.4 Dark Down 29.7 155.0 Low 08:48:51 - 09:18:51 6323
The Dalles 09:03:53 -22.7 Dark Down 29.8 154.6 Low 08:48:53 - 09:18:53 6301
Maupin 09:03:54 -23.0 Dark Down 30.2 154.6 Up 08:48:54 - 09:18:54 6275
Niwot 09:02:51 -23.0 Dark Down 38.4 171.8 Up 08:47:51 - 09:17:51 6246
SwRI 09:02:51 -23.1 Dark Down 38.5 171.7 Up 08:47:51 - 09:17:51 6236
Redmond 09:03:54 -23.9 Dark Down 31.0 154.3 Up 08:48:54 - 09:18:54 6212
Sisters 09:03:55 -24.0 Dark Down 30.9 153.8 Up 08:48:55 - 09:18:55 6205
Bend 09:03:55 -24.2 Dark Down 31.2 154.1 Up 08:48:55 - 09:18:55 6194
Oregon Observatory 09:03:55 -24.4 Dark Down 31.3 153.9 Up 08:48:55 - 09:18:55 6179
La Pine/Gilchrist 09:03:56 -24.6 Dark Down 31.4 153.7 Up 08:48:56 - 09:18:56 6164
North Lake 09:03:53 -24.9 Dark Down 32.0 154.3 Up 08:48:53 - 09:18:53 6146
Paisley 09:03:53 -25.3 Dark Down 32.6 154.5 Up 08:48:53 - 09:18:53 6115
Lakeview 09:03:52 -25.8 Dark Down 33.2 154.6 Up 08:48:52 - 09:18:52 6083
Klamath Falls 09:03:58 -26.0 Dark Down 32.7 153.0 Up 08:48:58 - 09:18:58 6054
Cedarville 09:03:53 -26.4 Dark Down 33.8 154.6 Up 08:48:53 - 09:18:53 6039
Fall River/Burney 09:03:57 -27.1 Dark Down 33.8 153.1 Up 08:48:57 - 09:18:57 5977
Susanville 09:03:54 -27.5 Dark Down 34.7 153.7 Up 08:48:54 - 09:18:54 5947
Gimple 09:03:56 -27.8 Dark Down 34.8 153.4 Up 08:48:56 - 09:18:56 5921
Greenville 09:03:56 -27.8 Dark Down 34.8 153.3 Up 08:48:56 - 09:18:56 5920
Portola 09:03:54 -28.1 Dark Down 35.3 153.8 Up 08:48:54 - 09:18:54 5906
Quincy 09:03:56 -28.0 Dark Down 35.0 153.3 Up 08:48:56 - 09:18:56 5904
Reno 09:03:52 -28.2 Dark Down 35.7 154.4 Up 08:48:52 - 09:18:52 5900
Carson City 09:03:52 -28.5 Dark Down 36.0 154.3 Up 08:48:52 - 09:18:52 5874
Yerington 09:03:49 -28.5 Dark Down 36.4 155.0 Up 08:48:49 - 09:18:49 5873
Gardnerville 09:03:52 -28.7 Dark Down 36.3 154.3 Up 08:48:52 - 09:18:52 5856
Hawthorne 09:03:48 -28.8 Dark Down 37.0 155.4 Up 08:48:48 - 09:18:48 5850
Tonopah 09:03:42 -28.9 Dark Down 37.9 156.9 Up 08:48:42 - 09:18:42 5846
Lee Vining 09:03:49 -29.5 Dark Down 37.4 154.7 Up 08:48:49 - 09:18:49 5796
Beatty 09:03:40 -29.8 Dark Down 39.1 157.1 Up 08:48:40 - 09:18:40 5766
Bishop 09:03:47 -29.9 Dark Down 38.2 155.3 Up 08:48:47 - 09:18:47 5766
Indian Springs 09:03:36 -29.8 Dark Down 39.7 158.3 Up 08:48:36 - 09:18:36 5765
Henderson 09:03:33 -30.1 Dark Down 40.4 158.9 Up 08:48:33 - 09:18:33 5739
Patrick 09:03:28 -30.3 Dark Down 41.3 160.1 Up 08:48:28 - 09:18:28 5715
DCO 09:03:25 -30.3 Dark Down 41.8 160.9 Up 08:48:25 - 09:18:25 5707
Searchlight/Boulder City 09:03:32 -30.6 Dark Down 41.0 158.8 Up 08:48:32 - 09:18:32 5696
Kingman/Dolan Springs 09:03:29 -30.6 Dark Down 41.5 159.8 Up 08:48:29 - 09:18:29 5693
Laughlin/Bullhead City 09:03:31 -30.8 Dark Down 41.4 159.2 Up 08:48:31 - 09:18:31 5679
Mohave Valley 09:03:31 -31.0 Dark Down 41.6 159.1 Up 08:48:31 - 09:18:31 5658
Lake Havasu City 09:03:30 -31.3 Dark Down 42.1 159.3 Up 08:48:30 - 09:18:30 5631
George/Scottsdale 09:03:19 -31.1 Dark Down 43.5 162.1 Up 08:48:19 - 09:18:19 5625
Parker 09:03:30 -31.6 Dark Down 42.4 159.2 Up 08:48:30 - 09:18:30 5604
Blythe 09:03:31 -32.2 Dark Down 42.8 158.6 Up 08:48:31 - 09:18:31 5555
CPSLO 09:03:58 -32.4 Dark Down 39.2 152.0 Up 08:48:58 - 09:18:58 5550
Idyllwild 09:03:41 -32.8 Dark Down 42.0 156.1 Up 08:48:41 - 09:18:41 5516
Wildwood 09:03:49 -33.0 Dark Down 41.0 153.9 Up 08:48:49 - 09:18:49 5500
Calipatria 09:03:36 -32.9 Dark Down 43.0 157.3 Up 08:48:36 - 09:18:36 5493
Yuma 09:03:31 -33.0 Dark Down 43.6 158.3 Up 08:48:31 - 09:18:31 5478

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 04HX78, (2026/05/21 09:01UT)
Object            RA         Dec     mag  sep  mel
Antares        16:29:24.4 -26:25:56  0.9 31.12 126
Nunki          18:55:15.9 -26:17:49  2.0 16.82 159
PPM 234462     18:23:12.2 -12:00:54  6.3  0.94 149
PPM 234491     18:24:29.6 -10:24:54  8.1  0.71 149
PPM 234486     18:24:14.5 -11:14:32  9.1  0.13 149
04HX78         18:24:28.2 -11:07:40 14.4       149
Positions are for J2000

Event circumstances last updated at 2020/03/31 22:10:10 UT

Marc W. Buie, Southwest Research Institute

RECON