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	2.074	15 38 03.23088	+51 21 36.3600	1350-08671081	234.513462	+51.360100			18.0	17.5	1955.320

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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
1	2.529	15 38 03.26136	+51 21 35.9424	EO1413-0342704	234.513589	+51.359984	17.76		1	9.53	9.7	0.28	18.21		1	13.88	11.4	0.45
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%3cEM%3e1&%3cFONT%20COLOR=%27#CD5B45%27>%202.529&%3cFONT%20COLOR=%27#CD5B45%27>15%2038%2003.26136&%3cFONT%20COLOR=%27#CD5B45%27>%2b51%2021%2035.9424&EO1413-0342704&234.513589&%2b51.359984&17.76&%20&%201&%20%20%209.53&%20%20%209.7&%200.28&18.21&%20&%201&%20%2013.88&%20%2011.4&%20%200.45&%20%3cBR%3e">\Ahref='VizieR-5?-ref=VIZ661e5f1127f762&-out.add=.&-source=I%2f267%2fout&APM-ID===EO1413-0342497&-out.orig=o' class='full'2 9.35615 38 02.73000+51 21 46.2132EO1413-0342497234.511375+51.36283719.52  -1 -3.28 3.5 0.0721.88L 0     2.36   %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	1.864	15 38 03.21456	+51 21 36.5256	N132102211259	234.513394	+51.360146	1991.281	17.66	0.43	18.45	0.42	3	4.50	0.35

%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%2fgalaxy%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:%2f%2fwww.nofs.navy.mil%2fdata%2ffchpix%2f%20%3cBR%3e%0a%3cB%3e%3cFONT%20COLOR=%27#EE0000%27>%20Note%20that%20the%20star%2fgalaxy%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	1.660	15 38 03.19008	+51 21 36.5220	1413-0259122	234.513292	+51.360145	117	79	1977.9	0	0	5	17.87	17.96	18.75	17.41	17.27
2	4.740	15 38 02.52816	+51 21 37.0404	1413-0259119	234.510534	+51.360289	999	27	1966.9	-212	18	3	19.85	20.15	20.86
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%3cEM%3e2&%3cFONT%20COLOR=%27#CD5B45%27>%204.740&%3cFONT%20COLOR=%27#CD5B45%27>15%2038%2002.52816&%3cFONT%20COLOR=%27#CD5B45%27>%2b51%2021%2037.0404&1413-0259119&234.510534&%2b51.360289&999&%2027&1966.9&%20%20-212&%20%20%20%2018&3&19.85&20.15&20.86&%20&%20%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	1.661	15 38 03.190008	+51 21 36.51984	1413-0263415	Y.	234.5132917	+51.3601444	B	0.0	0.0	0.0	0.0	18.350	Y			17.410	B
2	4.741	15 38 02.527992	+51 21 37.04004	1413-0263412	..	234.5105333	+51.3602889	B	-212.0	37.0	18.0	0.0	20.860	B			20.150	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 1.86615 38 03.21480+51 21 36.5256N5ZE011259234.513395+51.3601461991.28117.6618.4517.9617.653 4.50 0.35 2 9.89615 38 03.23328+51 21 47.0160N5ZE011271234.513472+51.3630601991.28120.45      3 2.15 0.39 %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	1.677	15 38 03.18072	+51 21 36.3456	234.513253	+51.360096	-2.6	0.3			17.87	18.75	17.96	17.41	17.27	5	0
2	4.738	15 38 02.53032	+51 21 36.8064	234.510543	+51.360224	-206.7	17.7			19.85	20.86	20.15			3	0

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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****]
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magG

%20

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

magGrvs
mag

e_
mag

alphaEpoch
yr

deltaEpoch
yr

pmRA
mas/yr

e_
(...)

pmDE
mas/yr

e_
(...)

1 2.10915 38 03.24686+51 21 36.6258234.513529+51.360174 0.025 0.02518.453 0.30017.660 0.30018.195 0.08217.357 0.1112001.39002001.3900 -2.6 5.5 0.3 5.5 2 4.73815 38 02.53035+51 21 36.8060234.510543+51.360224 0.133 0.13320.860 0.40020.150 0.40020.312 0.40019.694 0.5001966.98001966.9800 -206.7 8.1 17.7 8.1 %0a%0a%3cP%3e%0a%3cFONT%20SIZE=%27-1%27%3e%3cEM%3e%3cFONT%20COLOR=%27#0000FF%27>%3cB%3eNote:%20%3cP%3e%0a

Full	_r arcsec	_RAJ2000 "h:m:s"	_DEJ2000 "d:m:s"	RAICRS deg	e_ mas	DEICRS deg	e_ mas	ID	Type	pmRA mas/yr	e_ (...)	pmDE mas/yr	e_ (...)	Nobs	Dt yr	Rmag mag	Bmag mag	Nmag mag	Vmag mag	Jmag mag	Hmag mag	Kmag mag
1	1.788	15 38 03.194332	+51 21 36.33694	234.5133097	170.00	+51.3600936	95.00	56906+0011259	4	-3.8	6.2	1.6	3.5	6	42.036	17.660	18.453	17.653	17.963

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