The 3 columns in color are computed by VizieR, and are not part of the original data.

Note: USNO-A2.0 contains 526,280,881 sources, and is based on a re-reduction of the Precision Measuring Machine (PMM) scans from POSS-I O and E plates (>=-18°) and SRC-J and ESO-R plates (<=-20°). USNO-A2.0 was created by Dave Monet () and collaborators at Flagstaff Station, U.S. Naval Observatory.
The major difference between USNO-A2.0 and its previous version USNO-A1.0 is that A1.0 used the Guide Star Catalog as its reference frame whereas A2.0 uses the ICRF as realized by the USNO ACT catalog (Urban et al. 1997). The VizieR search engine uses an on-line compressed version (3.6Gbytes) which was generated at CDS.

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	USNO-A2.0	RAJ2000 deg	DEJ2000 deg	ACTflag	Mflag	Bmag mag	Rmag mag	Epoch yr
1	1.050	18 10 16.55016	+50 10 48.3816	1350-09530408	272.568959	+50.180106			16.8	15.4	1950.383
2	28.213	18 10 19.55472	+50 10 43.8312	1350-09530833	272.581478	+50.178842			20.0	18.6	1950.383

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Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	APM-ID	RAJ2000 deg	DEJ2000 deg	rmag mag	l_	rClass	rStel	rDiam arcsec	rEll	bmag mag	l_	bClass	bStel	bDiam arcsec	b-r mag	Mflag [****ClosingBrace(s)Inserted****]
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Mflag

%22> 1 0.84618 10 16.57944+50 10 48.4500EO0130-0066616272.569081+50.18012515.31   1 8.60 13.6 0.2416.83   1 11.20 14.9 1.52   228.32118 10 19.56288+50 10 43.6224EO0130-0066699272.581512+50.17878418.71  -1 0.33 5.8 0.2221.60  -1 -1.45 3.6 2.89   %0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20construction%20of%20the%20%0a%3cB%3eGSC-II%20%0ais%20still%20in%20progress:%20this%0aversion%20has%20no%20proper%20motions,%20and%20the%20magnitude%20limits%20are%2018.5%20in%20F%20%28red%29%0aand%2019.5%20in%20J%20%28blue%29.%20The%20data%20are%20%3cB%3e%3cFONT%20COLOR=%27#0000CD%27>copyrighted,%20check%20%0athe%20%3cB%3edata%20use%20Policy.%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC2.2	RA(ICRS) deg	DE(ICRS) deg	Epoch yr	Rmag mag	e_ mag	Bjmag mag	e_ mag	Class	a pix	e
1	0.929	18 10 16.57200	+50 10 48.4932	N011002215778	272.569050	+50.180137	1993.623	15.29	0.41	16.33	0.42	3	5.02	0.31

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20%3cB%3eUSNO-B%20Catalog%20presents%20positions,%20proper%20motions,%20%0amagnitudes%20un%20blue,%20red%20and%20infrared,%20as%20well%20as%20star/galaxy%20estimators%0afor%201,045,175,762%20objects%20derived%20from%203,648,832,040%20separate%20observations.%0aThe%20data%20were%20taken%20from%20scans%20of%207,435%20Schmidt%20plates%0ataken%20from%20various%20sky%20surveys%20during%20the%20last%2050%20years.%3cBR%3e%0aUSNO-B1.0%20catalog%20was%20created%20by%20Dave%20Monet%20and%20collaborators%0aat%20http://www.nofs.navy.mil/data/fchpix/%20%3cBR%3e%0a%3cB%3e%3cFONT%20COLOR=%27#EE0000%27>%20Note%20that%20the%20star/galaxy%20estimators%20may%20be%20mixed%20up%0a%20in%20dense%20regions.%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	USNO-B1.0	RAJ2000 deg	DEJ2000 deg	e_RAJ2000 mas	e_DEJ2000 mas	Epoch yr	pmRA mas/yr	pmDE mas/yr	Ndet	B1mag mag	R1mag mag	B2mag mag	R2mag mag	Imag mag
1	0.845	18 10 16.58736	+50 10 48.5328	1401-0302421	272.569114	+50.180148	65	156	1976.8	8	2	5	17.15	15.73	15.93	15.10	14.68
2	28.009	18 10 19.53480	+50 10 43.9320	1401-0302433	272.581395	+50.178870	186	117	1976.8	0	0	5	20.82	18.92	20.67	19.30	18.53
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%3cEM%3e2&%3cFONT%20COLOR=%27#CD5B45%27>28.009&%3cFONT%20COLOR=%27#CD5B45%27>18%2010%2019.53480&%3cFONT%20COLOR=%27#CD5B45%27>%2b50%2010%2043.9320&1401-0302433&272.581395&%2b50.178870&186&117&1976.8&%20%20%20%20%200&%20%20%20%20%200&5&20.82&18.92&20.67&19.30&18.53%3cBR%3e">\Ahref='VizieR-5?-ref=VIZ662a44971d3ecd&-out.add=.&-source=I/284/out&USNO-B1.0===1401-0302434&-out.orig=o' class='full'329.62018 10 19.55400+50 10 38.00281401-0302434272.581475+50.1772239999991972.0 0 0219.82    20.65   %0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20The%20Naval%20Observatory%20Merged%20Astrometric%20Dataset%20%28NOMAD%29%20contains%0aastrometric%20and%20photometric%20data%20for%20over%201%20billion%20stars%20derived%20from%0athe%20Hipparcos%20%28I/239%29,%20Tycho-2%20%28I/259%29,%20UCAC2%20%28I/289%29,%20and%20USNO-B1.0%0a%28I/284%29%20catalogs%20for%20astrometry%20and%20optical%20photometry,%20supplemented%0aby%202MASS%20%28II/246%29%20near-infrared%20photometry.%3cBR%3e%0a%3cFONT%20SIZE=%27-1%27%3eAn%20efficient%20remote%20query%20program%20%3cB%3efindnomad1%20is%0aavailable%20in%20the%20cdsclient%20%0apackage,%20for%20Unix/Linux%20platforms%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	NOMAD1	YM	RAJ2000 deg	DEJ2000 deg	r	pmRA mas/yr	e_ (...)	pmDE mas/yr	e_ (...)	Bmag mag	r_	Vmag mag	r_	Rmag mag	r_	Jmag mag	Hmag mag	Kmag mag	R
1	0.843	18 10 16.587336	+50 10 48.52992	1401-0306155	YM	272.5691139	+50.1801472	B	8.0	2.0	2.0	4.0	17.200	Y	16.680	Y	15.100	B	15.557	14.865	14.782
2	28.008	18 10 19.534656	+50 10 43.92984	1401-0306167	..	272.5813944	+50.1788694	B	0.0	0.0	0.0	0.0	20.670	B			19.300	B
3	29.621	18 10 19.554000	+50 10 37.99992	1401-0306168	..	272.5814750	+50.1772222	B	0.0	0.0	0.0	0.0	19.820	o			20.650	B

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20Zone%20-30/%2b50deg%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	CMC14 [****ClosingBrace(s)Inserted****]
">

CMC14

%20

%22>f_

RAICRS
deg

DEICRS
deg

r'mag
mag

Nt

Jmag
mag

Hmag
mag

Ksmag
mag

1 1.10918 10 16.54128+50 10 48.3312181016.5+501048  272.568922+50.18009216.827 115.55714.865   %0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20This%20version%20of%20the%20%0a%3cB%3eGSC-II%0ahas%20no%20proper%20motions,%20but%20the%20limits%20on%20brightness%20which%20existed%20on%0a%20%28F<18.5,%20B_j<19.5%29%20were%20removed.%0a%25The%20data%20are%20%3cB%3e%3cFONT%20COLOR=%27#0000CD%27>copyrighted,%20check%0a%25the%20%3cB%3edata%20use%20Policy.%0a%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC2.3	RAJ2000 deg	DEJ2000 deg	Epoch yr	Fmag mag	jmag mag	Vmag mag	Nmag mag	Class	a pix	e
1	0.928	18 10 16.57224	+50 10 48.4932	N0ZU015778	272.569051	+50.180137	1993.623	15.29	16.33	16.43	15.02	3	5.02	0.31
2	22.191	18 10 15.03984	+50 10 32.0052	N0ZU027159	272.562666	+50.175557	1993.623	20.40				3	1.47	0.18
3	28.191	18 10 19.55256	+50 10 43.8384	N0ZU015763	272.581469	+50.178844	1993.623	19.20	21.13	19.37	18.59	0	2.14	0.09

%0a%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	RAJ2000 deg	DEJ2000 deg	pmRA mas/yr	pmDE mas/yr	Jmag mag	Kmag mag	b1mag mag	b2mag mag	r1mag mag	r2mag mag	imag mag	[****ClosingBrace(s)Inserted****]
">

mag&%">\BegDIVclass='sort-down ' </A>decNo

fl

1 1.03118 10 16.55064+50 10 48.3456272.568961+50.180096 -0.2 -1.915.55714.78317.1515.9315.7315.1014.68 6 0 227.09818 10 19.35960+50 10 40.4292272.580665+50.177897 -38.1 52.1    19.82    20.65   2 0 327.88818 10 19.52112+50 10 43.8672272.581338+50.178852 0.5 1.8    20.8220.6718.9219.3018.53 5 0 %0a%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	ID	RAICRS deg	DEICRS deg	pmRAp mas/yr	pmDEp mas/yr	pmRAx mas/yr	pmDEx mas/yr	Fmag mag	Bjmag mag	Vmag mag	Nmag mag	Jmag mag	e_ mag	Hmag mag	e_ mag	Kmag mag	e_ mag	2Mkey	Bmag mag	Rmag mag	Fld	dT yr	fg	fs	M
1	1.166	18 10 16.53648	+50 10 48.3706	XPM 280-0421641	272.568902	+50.180103	0.75	3.14	0.96	3.65	15.286	16.334	16.433	15.017	15.557	0.090	14.865	0.107	14.783	0.115	1119475719	16.8	15.4	182	49.939865	0	0	M

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Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	[****ClosingBrace(s)Inserted****]
">

%22d:m:s%22&%">\BegDIVclass='sort-down ' </A>decRAJ2000
degDEJ2000
deg

e_RAJ2000
(...)

e_DEJ2000
arcsec

magBJ
mag

e_
mag

magRF
mag

e_
mag

magG
mag

e_
mag

magGrvs
mag

e_
mag

alphaEpoch
yr

deltaEpoch
yr

pmRA
mas/yr

e_
(...)

pmDE
mas/yr

e_
(...)

1 1.03118 10 16.55067+50 10 48.3461272.568961+50.180096 0.070 0.07016.334 0.30015.286 0.30015.503 0.40014.642 0.5001989.47001989.4700 -0.2 3.7 -1.9 3.7 227.09818 10 19.35963+50 10 40.4287272.580665+50.177897 0.163 0.16319.820 0.40020.650 0.40020.386 0.40020.951 0.5001972.00001972.0000 -38.1 7.5 52.1 7.5 327.88918 10 19.52116+50 10 43.8666272.581338+50.178852 0.103 0.10321.129 0.30019.197 0.30019.397 0.40017.970 0.5001976.88001976.8800 0.5 4.8 1.8 4.8 %0a%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20Zone%20-40/%2b50deg%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	CMC15	RA_ICRS deg	DE_ICRS deg	r'mag mag	pflag	Nt	Jmag mag	Hmag mag	Ksmag mag
1	1.110	18 10 16.54129	+50 10 48.3350	181016.5+501048	272.568922	+50.180093	16.827		1	15.557	14.865

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20%3cP%3e%0a