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	0.347	17 12 30.91008	+26 01 06.8808	1125-08077078	258.128792	+26.018578			18.2	18.5	1951.506

%0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20%3cB%3e%3cFONT%20COLOR=%27#CD5B45%27>%20The%20current%20version%20includes%20only%20the%20North%20%28POSS-I%20plates%29%3cP%3e%0a

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
1	0.410	17 12 30.92616	+26 01 06.6108	EO1377-0049503	258.128859	+26.018503	18.33		1	5.37	7.5	0.07	19.17		1	9.43	8.0	0.84
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%3cEM%3e1&%3cFONT%20COLOR=%27#CD5B45%27>%200.410&%3cFONT%20COLOR=%27#CD5B45%27>17%2012%2030.92616&%3cFONT%20COLOR=%27#CD5B45%27>%2b26%2001%2006.6108&EO1377-0049503&258.128859&%2b26.018503&18.33&%20&%201&%20%20%205.37&%20%20%207.5&%200.07&19.17&%20&%201&%20%20%209.43&%20%20%208.0&%20%200.84&%20%3cBR%3e">\Ahref='VizieR-5?-ref=VIZ6639817aa6206&-out.add=.&-source=I/267/out&APM-ID===EO0263-0051015&-out.orig=o' class='full'2 0.51717 12 30.96552+26 01 06.7116EO0263-0051015258.129023+26.01853119.78   1 5.95 5.6 0.4219.93   1 9.29 9.0 0.16   %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	0.323	17 12 30.93120	+26 01 06.6864	N101300312460	258.128880	+26.018524	1996.239	17.83	0.42	18.88	0.41	3	3.80	0.11

%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	0.237	17 12 30.95136	+26 01 07.0500	1160-0256655	258.128964	+26.018625	75	234	1974.2	0	0	4	18.96	18.75	17.77	17.55
2	3.783	17 12 30.66288	+26 01 07.9824	1160-0256652	258.127762	+26.018884	187	999	1973.4	-72	26	4	19.00	17.83	20.69		18.00
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%3cEM%3e2&%3cFONT%20COLOR=%27#CD5B45%27>%203.783&%3cFONT%20COLOR=%27#CD5B45%27>17%2012%2030.66288&%3cFONT%20COLOR=%27#CD5B45%27>%2b26%2001%2007.9824&1160-0256652&258.127762&%2b26.018884&187&999&1973.4&%20%20%20-72&%20%20%20%2026&4&19.00&17.83&20.69&%20&18.00%3cBR%3e">\EndTABLESORT

Note: The Naval Observatory Merged Astrometric Dataset (NOMAD) contains astrometric and photometric data for over 1 billion stars derived from the Hipparcos (I/239), Tycho-2 (I/259), UCAC2 (I/289), and USNO-B1.0 (I/284) catalogs for astrometry and optical photometry, supplemented by 2MASS (II/246) near-infrared photometry.
An efficient remote query program findnomad1 is available in the cdsclient package, for Unix/Linux platforms

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	0.237	17 12 30.951336	+26 01 07.05000	1160-0261686	..	258.1289639	+26.0186250	B	0.0	0.0	0.0	0.0	17.770	B			17.550	B
2	3.785	17 12 30.662664	+26 01 07.97988	1160-0261683	..	258.1277611	+26.0188833	B	-72.0	5.0	26.0	57.0	20.690	B			17.830	e

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Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC2.3	RAJ2000 deg	DEJ2000 deg	Epoch yr	[****ClosingBrace(s)Inserted****]
">

yr&%">\BegDIVclass='sort-down ' </A>decFmag
magjmag
mag

Vmag
magNmag
magClass

a
pixe

1 0.31917 12 30.93144+26 01 06.6900N3IB012460258.128881+26.0185251996.23917.8318.88  18.503 3.80 0.11 %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	No	fl
1	0.205	17 12 30.94224	+26 01 06.8340	258.128926	+26.018565	-8.7	-10.3			18.96	17.77	18.75	17.55		4	0
2	4.091	17 12 30.65832	+26 01 08.7168	258.127743	+26.019088	-77.6	39.5			19.00	20.69	17.83		18.00	4	1

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Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	RAJ2000 deg	DEJ2000 deg	e_RAJ2000 (...)	e_DEJ2000 arcsec	magBJ mag	e_ mag	magRF mag	e_ mag	magG [****ClosingBrace(s)Inserted****]
">

magG

%20

%22>%5cFONT SIZE=-1mage_
mag

magGrvs
mag

e_
mag

alphaEpoch
yr

deltaEpoch
yr

pmRA
mas/yr

e_
(...)

pmDE
mas/yr

e_
(...)

1 0.16917 12 30.93487+26 01 06.8389258.128895+26.018566 0.035 0.03918.878 0.30017.833 0.30018.465 0.08417.664 0.1132002.43002002.4300 -8.7 6.0 -10.3 6.0 2 4.09117 12 30.65832+26 01 08.7173258.127743+26.019088 0.115 0.13320.690 0.40017.830 0.40017.660 0.40015.784 0.5001973.42001973.4200 -77.6 5.7 39.5 6.3 %0a%0a%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	GSC2	RA_ICRS deg	DE_ICRS deg	objID	Epoch yr	Class	Gmag mag	OMag mag	Bjmag mag	Fpgmag mag	Epgmag mag	Npgmag mag	Umag mag	Bmag mag	Vmag mag	umag mag	gmag mag	rmag mag	imag mag	zmag mag	ymag mag	Jmag mag	Hmag mag	Ksmag mag	Zmag mag	Ymag mag	W1mag mag	W2mag mag	W3mag mag	W4mag mag	FUVmag mag	NUVmag mag	a pix	e pix	PA pix
1	0.164	17 12 30.9334144478	+26 01 08.146462605	N3IB012460	258.12889681000	+26.01856772000	1101300312460	2011.994	3			18.878100	17.833300		18.500800				19.923	20.507	20.205	19.805	19.760	19.3769												3.799	0.108	131.1
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1	0.164	17 12 30.9334144478	+26 01 08.146462605	N3IB012460	258.12889681000	+26.01856772000	1101300312460	2011.994	3			18.878100	17.833300		18.500800				19.923	20.507	20.205	19.805	19.760	19.3769												3.799	0.108	131.1

%22>\EndTABLESORT

Note: SDSS is also available from http://www.sdss.org/