J/AJ/164/36 The USNO Bright Star Catalog (UBSC) version 1 (Zacharias+, 2022)
USNO Bright Star Catalog, Version 1.
Zacharias N., Makarov V.V., Finch C.T., Harris H.C., Munn J.A.,
Subasavage J.P.
<Astron. J., 164, 36 (2022)>
=2022AJ....164...36Z 2022AJ....164...36Z
ADC_Keywords: Stars, bright; Photometry, infrared; Proper motions;
Parallaxes, trigonometric
Keywords: Astrometry ; Catalogs ; Proper motions ; Trigonometric parallax
; Astrometric binary stars
Abstract:
The U.S. Naval Observatory (USNO) Bright Star Catalog (UBSC) is a new
astrometric catalog of the 1423 brightest stars covering the entire
sky, which is published online. It is nearly complete to V=3mag except
for three stellar systems. A combined astrometric solution of the
Hipparcos Intermediate Astrometry Data and two dedicated ground-based
campaigns in 2013-2020 is the basis for this catalog. The astrometric
parameters for each star include position coordinates, parallax, and
proper motion components, and their covariances on the Hipparcos mean
epoch 1991.25. 64% of the catalog are flagged as known or suspected
double or binary stars. UBSC lists 68 stars missing in Gaia EDR3 and
another 114 stars without Gaia parallaxes or proper motions. The
formal precision achieved for proper motions is comparable to that of
Gaia.
Description:
The U.S. Naval Observatory (USNO) Bright-Star Astrometric Database
(UBAD) provides accurate, current-epoch astrometry for bright
northern-hemisphere stars. Observations were obtained from 2016 to
2020 using a 2048x4092 e2v CCD on the USNO, Flagstaff Station, Kaj
Strand 61inch Astrometric Reflector. All observations were taken using
either an i or z filter, and mostly within a 1hr angle of the
meridian, so as to minimize the effects of differential chromatic
refraction. The exposure times vary between 15 and 1200s, with a modal
value around 250s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 202 1423 *The USNO Bright Star Catalog
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Note on table2.dat : All astrometric parameters and covariances are on
the ICRS, epoch J1991.25.
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/A+A/397/997 : Hipparcos red stars (Platais+, 2003)
J/A+A/399/1167 : Hipparcos Variability-Induced Movers (Pourbaix+, 2003)
J/AJ/129/2420 : Proper motion derivatives of binaries (Makarov+, 2005)
J/AJ/131/2967 : α Persei open cluster members (Makarov+, 2006)
J/A+A/623/A72 : Binarity of Hipparcos stars Gaia pm anomaly (Kervella+, 2019)
J/ApJS/254/42 : Hipparcos-Gaia (EDR3) Catalog of Accelerations (Brandt, 2021)
J/AJ/163/131 : USNO-UBAD catalog of bright stars (Munn+, 2022)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos identifier
8- 14 F7.4 mag Hpmag [-0.56/7.98] Hipparcos apparent magnitude
16- 21 F6.3 mag B-V [-0.27/3.34] The (B-V) color from Hipparcos
23 I1 --- Bin [0/7] Binarity/perturbed flag (1)
25 I1 --- Source [1/3] Source flag (2)
27- 29 I3 --- Num [23/628] Number of observational equations in
HUU
31- 39 F9.2 --- chi2 [22/910911] The χ2 of residuals
41- 45 F5.2 mas MAD [0.32/26.9] MAD of residuals * 1.5
47- 58 F12.8 deg RAdeg [0/360] Right Ascension in decimal degrees
(ICRS) at Epoch=1991.25
60- 71 F12.8 deg DEdeg [-85/78] Declination in decimal degrees
(ICRS) at Epoch=1991.25
73- 79 F7.2 mas plx [-329/311] Parallax
81- 88 F8.2 mas/yr pmRA [-1722/2221] Proper motion along RA
90- 97 F8.2 mas/yr pmDE [-2000/1165] Proper motion along DE
99-102 F4.2 mas e_RAdeg [0.2/2] Uncertainty in RAdeg
104-107 F4.2 mas e_DEdeg [0.2/0.8] Uncertainty in DEdeg
109-112 F4.2 mas e_plx [0.3/2] Uncertainty in plx
114-117 F4.2 mas/yr e_pmRA [0.03/0.9] Uncertainty in pmRA
119-122 F4.2 mas/yr e_pmDE [0.03/0.7] Uncertainty in pmDE
124-130 F7.4 mas2 c12 [-0.32/0.32] Covariance c12 value
132-138 F7.4 mas2 c13 [-0.55/0.53] Covariance c13 value
140-146 F7.4 mas2/yr c14 [-0.25/0.1] Covariance c14 value
148-154 F7.4 mas2/yr c15 [-0.14/0.12] Covariance c15 value
156-162 F7.4 mas2 c23 [-0.44/0.19] Covariance c23 value
164-170 F7.4 mas2/yr c24 [-0.1/0.07] Covariance c24 value
172-178 F7.4 mas2/yr c25 [-0.18/0.12] Covariance c25 value
180-186 F7.4 mas2/yr c34 [-0.11/0.14] Covariance c34 value
188-194 F7.4 mas2/yr c35 [-0.09/0.11] Covariance c35 value
196-202 F7.4 mas2/yr2 c45 [-0.08/0.14] Covariance c45 value
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Note (1): Flags as follows:
0 = star not know to be perturbed (518 occurrences)
1 = HIP Mult_flag C, resolved double or multiple star (164 occurrences)
2 = HIP Mult_flag X, stocahstic (or failed) solution (20 occurrences)
3 = HIP Mult_flag G, accelerating star (79 occurrences)
4 = HIP Mult_flag V, variability-induced motion (23 occurrences
5 = HIP Mult_flag O, physical binary with an orbital solution (59 occurrences)
6 = an astrometric binary, candidate unresolved binary with statistically
significant difference between the UBSC and Gaia EDR3 proper motions
and not in categories 1-5 (557 occurrences)
7 = an astrometric binary, from Makarov & Kaplan, 2005, J/AJ/129/2420
catalog (3 occurrences)
Note (2): Flags as follows:
1 = a star with a solution based on UBAD and HIAD only (212 occurrences)
2 = a star with a solution based on URAT and HIAD only (1058 occurrences)
3 = a star with a solution based on all 3 sources (153 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 24-Oct-2022