RECON: TNO occultation with 54598

Event between (54598) Bienor and star GA1240:03239738 with event index number of 1477821

Geocentric closest approach at 2025/11/19 11:07:01 UTC

J2000 position of star is 08:18:19.5 +35:03:24
Equinox of date position of star is 08:19:52.4 +34:58:48
Stellar brightness G=15.0, use SENSEUP=128 with the MallinCam and and exposure time of 2 seconds with the QHY174 camera.
Star is 110 degrees from the moon. Moon is 1% illuminated.
Apparent brightness V=18.9

[RECON map]
Object is 13.3 AU from the Sun and 12.8 AU from the Earth.
Apparent velocity is 7.4 km/sec on the sky relative to the star, or, 2.9 arcsec/hr.
The 1-sigma error in the time of the event is 77 seconds.
The 1-sigma cross-track error in the shadow position is 560 km.
The sky-plane scale is 9291.7 km/arcsec.

The object has an absolute magnitude Hv=7.4
Diameter=195.0 km assuming a 5% albedo -- 26.3 sec chord
Diameter=79.6 km assuming a 30% albedo -- 10.7 sec chord
Dynamical classification is CENTAURR
 
 
 
 
 
 

Star training set for 54598, (2025/11/19 11:07UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:46:54.0 +27:57:42  1.1  9.94 116
32 Lyn         08:35:01.0 +36:20:48  6.5  3.35 108
PPM 073603     08:21:11.1 +34:57:46  7.6  0.25 110
54598          08:19:59.0 +34:58:28 15.0       110
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 15.9 km RECON observability=1.0 and success probability=4.7%

Site	Site mid-time (UT)	Sun alt (deg)	Sky	Moon	Star alt (deg)	Star az (deg)	Target	Observing Time (UT)	X-track (km)
Sleaford	11:10:28	-30.4	Dark	Down	72.7	168.5	Up	11:03:31 - 11:17:24	2908
Kamloops	11:11:54	-39.3	Dark	Down	69.6	132.8	Up	11:04:58 - 11:18:51	2134
Kelowna	11:11:41	-39.0	Dark	Down	70.5	132.8	Up	11:04:44 - 11:18:37	2099
Peachland	11:11:43	-39.2	Dark	Down	70.4	132.0	Up	11:04:46 - 11:18:39	2077
Summerland	11:11:40	-39.2	Dark	Down	70.6	131.9	Up	11:04:44 - 11:18:37	2067
Penticton	11:11:39	-39.1	Dark	Down	70.7	132.0	Up	11:04:43 - 11:18:36	2066
Dunrhomin	11:08:21	-30.9	Dark	Down	83.9	147.9	Up	11:01:25 - 11:15:18	2035
Oliver	11:11:37	-39.3	Dark	Down	70.9	131.2	Up	11:04:40 - 11:18:33	2035
Anarchist Mountain Observatory	11:11:33	-39.2	Dark	Down	71.1	131.2	Up	11:04:37 - 11:18:30	2028
Nikitin	11:08:20	-30.9	Dark	Down	84.1	146.8	Up	11:01:23 - 11:15:16	2019
CU-SBO	11:08:20	-31.0	Dark	Down	84.1	145.9	Up	11:01:23 - 11:15:16	2009
Okanogan	11:11:30	-39.5	Dark	Down	71.4	129.3	Up	11:04:34 - 11:18:27	1961
Brewster	11:11:29	-39.7	Dark	Down	71.5	128.2	Up	11:04:33 - 11:18:26	1927
Manson/Chelan	11:11:30	-40.0	Dark	Down	71.4	127.0	Up	11:04:33 - 11:18:26	1892
Wenatchee	11:11:27	-40.3	Dark	Down	71.6	125.5	Up	11:04:31 - 11:18:24	1842
Victoria	11:12:00	-41.8	Dark	Down	69.3	122.8	Up	11:05:04 - 11:18:57	1812
Ellensburg	11:11:26	-40.5	Dark	Down	71.7	124.1	Up	11:04:30 - 11:18:23	1795
PNWRO	11:11:06	-39.7	Dark	Down	73.1	124.5	Up	11:04:09 - 11:18:02	1781
Yakima	11:11:22	-40.7	Dark	Down	71.9	123.0	Up	11:04:25 - 11:18:18	1757
Toppenish/White Swan	11:11:20	-40.6	Dark	Down	72.1	122.7	Up	11:04:23 - 11:18:16	1746
The Dalles	11:11:20	-41.3	Dark	Down	72.0	119.2	Up	11:04:23 - 11:18:16	1640
Maupin	11:11:15	-41.4	Dark	Down	72.3	118.2	Up	11:04:18 - 11:18:11	1606
Sisters	11:11:12	-42.0	Dark	Down	72.4	114.9	Up	11:04:16 - 11:18:09	1504
Bend	11:11:08	-41.9	Dark	Down	72.6	114.6	Up	11:04:11 - 11:18:04	1494
Oregon Observatory	11:11:07	-42.0	Dark	Down	72.6	113.9	Up	11:04:10 - 11:18:03	1472
Chiloquin	11:11:00	-42.6	Dark	Down	72.8	109.2	Up	11:04:03 - 11:17:56	1333
Cedarville	11:10:36	-41.7	Dark	Down	74.2	108.3	Up	11:03:39 - 11:17:32	1320
Klamath Falls	11:10:57	-42.6	Dark	Down	72.9	108.3	Up	11:04:00 - 11:17:53	1306
Fall River/Burney	11:10:43	-42.6	Dark	Down	73.5	105.0	Up	11:03:47 - 11:17:40	1217
Gimple	11:10:31	-42.5	Dark	Down	74.1	102.5	Up	11:03:34 - 11:17:27	1161
Reno	11:10:18	-41.8	Dark	Down	75.0	101.7	Up	11:03:22 - 11:17:15	1160
Greenville	11:10:31	-42.5	Dark	Down	74.0	102.5	Up	11:03:35 - 11:17:28	1157
Portola	11:10:24	-42.2	Dark	Down	74.4	101.9	Up	11:03:28 - 11:17:21	1151
Yerington	11:10:06	-41.4	Dark	Down	75.5	100.3	Up	11:03:10 - 11:17:03	1144
Quincy	11:10:30	-42.6	Dark	Down	74.1	101.8	Up	11:03:33 - 11:17:26	1139
Hawthorne	11:09:58	-41.1	Dark	Down	76.0	99.1	Up	11:03:01 - 11:16:54	1130
Carson City	11:10:13	-41.9	Dark	Down	75.0	100.4	Up	11:03:17 - 11:17:10	1129
Patrick	11:08:47	-37.8	Dark	Down	79.8	88.4	Up	11:01:51 - 11:15:44	1124
Gardnerville	11:10:11	-41.9	Dark	Down	75.1	99.5	Up	11:03:14 - 11:17:07	1110
George/Scottsdale	11:08:13	-36.3	Dark	Down	81.1	78.3	Up	11:01:17 - 11:15:10	1101
Beatty	11:09:26	-39.9	Dark	Down	77.5	94.0	Up	11:02:30 - 11:16:23	1088
Laughlin/Bullhead City	11:08:51	-38.4	Dark	Down	79.2	86.8	Up	11:01:55 - 11:15:48	1062
Lee Vining	11:09:57	-41.6	Dark	Down	75.7	96.4	Up	11:03:01 - 11:16:54	1055
Bishop	11:09:45	-41.1	Dark	Down	76.3	94.6	Up	11:02:48 - 11:16:41	1040
Lake Havasu City	11:08:42	-38.2	Dark	Down	79.3	83.3	Up	11:01:46 - 11:15:39	1020
Yuma	11:08:29	-38.5	Dark	Down	78.7	74.3	Up	11:01:32 - 11:15:25	850
Calipatria	11:08:41	-39.2	Dark	Down	78.1	76.7	Up	11:01:44 - 11:15:37	834
Idyllwild	11:08:57	-40.1	Dark	Down	77.3	79.7	Up	11:02:01 - 11:15:54	817
Wildwood	11:09:18	-41.6	Dark	Down	75.9	81.2	Up	11:02:21 - 11:16:14	743

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 54598, (2025/11/19 11:07UT)
Object            RA         Dec     mag  sep  mel
Pollux         07:45:17.9 +28:01:33  1.1  9.94 116
32 Lyn         08:33:21.5 +36:26:11  6.5  3.35 108
PPM 073603     08:19:31.6 +35:02:44  7.6  0.25 110
54598          08:18:19.5 +35:03:24 15.0       110
Positions are for J2000

Event circumstances last updated at 2024/03/05 04:24:45 UT

RECON