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I/297                     NOMAD Catalog                        (Zacharias+ 2005)

Naval Observatory Merged Astrometric Dataset (NOMAD) Zacharias N., Monet D.G., Levine S.E., Urban S.E., Gaume R., Wycoff G.L. <San Diego AAS Meeting, January (2005)> =2004AAS...205.4815Z
ADC_Keywords: Positional data ; Proper motions ; Surveys ; Photometry, photographic ; Photometry, infrared Description: 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. For each unique star the "best" astrometric and photometric data are chosen from the source catalogs and merged into a single dataset. A sequence of priorities is followed and NOMAD contains flags to identify the source catalogs and gives cross-reference identifications. This first release of NOMAD is not a compiled catalog; that is, if a star is identified in more than 1 of the above mentioned catalogs, only 1 catalog entry is chosen. Thus the local and global systematic errors of the various source catalogs will be present in this version of NOMAD. All source catalogs astrometric data are on the International Celestial Reference System within the limitations of the source catalogs. For more information, see A dedicated remote query program can be downloaded from File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file out.sam 167 1523 Example of the an output of NOMAD-1
See also: : NOMAD Home Page I/239 : The Hipparcos and Tycho Catalogues (ESA 1997) I/259 : The Tycho-2 Catalogue (Hog+ 2000) I/284 : The USNO-B1.0 Catalog (Monet+ 2003) I/289 : UCAC2 Catalogue (Zacharias+ 2004) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) Byte-by-byte Description of file: out.sam
Bytes Format Units Label Explanations
1- 12 A12 --- NOMAD1 NOMAD-identifier (1) 14- 25 A12 --- USNO-B1 Identifier in USNO-B1 (Cat. I/284) (1) 27- 34 I8 --- UCAC2 ? Number in UCAC2 (Cat. I/289) 36- 47 A12 --- Tycho-2 ? Identification in Tycho-2 or Hipparcos (2) 48 A1 --- f_Tycho-2 [*] when distance NOMAD1/Tycho-2 > 1arcsec 49- 50 A2 --- YM [YM.] Existence in YB6 or 2MASS (Cat. II/246) 52- 62 F11.7 deg RAdeg Right ascension in ICRS, Ep=J2000 63- 73 F11.7 deg DEdeg Declination in ICRS, Ep=J2000 75 A1 --- r [BCMYTH] Source of position (3) 77- 80 I4 mas e_RAdeg Mean error on RAdeg (at epRA) 82- 85 I4 mas e_DEdeg Mean error on DEdeg (at epDE) 87- 94 F8.1 mas/yr pmRA Proper motion in RA (*cos(Dec)) 96-103 F8.1 mas/yr pmDE Proper motion in Declination 105-109 F5.1 mas/yr e_pmRA Mean error on pmRA 111-115 F5.1 mas/yr e_pmDE Mean error on pmDE 117-122 F6.3 mag Bmag ?Blue magnitude 123 A1 --- r_Bmag [BCMYTHo] Origin of Bmag (3) 125-130 F6.3 mag Vmag ?Visual magnitude 131 A1 --- r_Vmag [BCMYTH] Origin of Vmag (3) 133-138 F6.3 mag Rmag ?Red magnitude 139 A1 --- r_Rmag [BCMYTHe] Origin of Rmag (3) 141-146 F6.3 mag Jmag ?Infrared J magnitude (from 2MASS) 148-153 F6.3 mag Hmag ?Infrared H magnitude (from 2MASS) 155-160 F6.3 mag Kmag ?Infrared K magnitude (from 2MASS) 162-166 A5 --- Xflags [0-9a-f] Hexadecimal flags (4) 167 A1 --- R [R*] Recommended (R) or Problematic (*) (4)
Note (1): NOMAD and USNO designations consist in 2 numbers separated by a dash of the form: zone-number where zone (0000-1799) indicates a declination strip from the South Pole (0.1deg wide), and number is a sequential number increasing with right ascension. Note (2): The Tycho-2 number (Cat. I/259) is made of 3 numbers separated by 2dashes, while Hipparcos (Cat. I/239) is a sequential number. Note (3): Sources of the values are defined as follows: B = USNO-B1.0 (Monet et al., Cat. I/284) C = UCAC2 (Zacharias et al., Cat. I/289) M = 2MASS catalog of point sources (Cutri et al., Cat. II/246) Y = YB6 Catalog (USNO, unpublished) T = Tycho-2 Catalog (Hog et al., 2000, Cat. I/259) H = Hipparcos catalog (Table I/239/hip_main) o = Palomar-I blue (O) plate (for Bmag) e = Palomar-I red (E) plate (for Rmag) Note (4): Flags are written in hexadecimal (symbols 0-f) with the following meaning: 00001 = UBBIT : Fails Blaise's test for USNO-B1.0 star 00002 = TMBIT : Fails Roc's test for clean 2MASS star 00004 = YB6 : Included in YB6 catalog (Y) 00008 = 2MASS : Included in 2MASS catalog (M) 00010 = TYBIT : Astrometry comes from Tycho2 catalog (T) 00020 = XRBIT : Alternative correlations for same (RA,Dec) 00040 = ITMBIT : Alternative correlations for same 2MASS ID 00080 = IUCBIT : Alternative correlations for same UCAC-2 ID 00100 = ITYBIT : Alternative correlations for same Tycho2 ID 00200 = OMAGBIT : Blue magnitude from O (not J) plate (o) 00400 = EMAGBIT : Red magnitude from E (not F) plate (e) 00800 = TMONLY : Object found only in 2MASS catalog (M) 01000 = HIPAST : Ast from Hipparcos catalog (H) 02000 = SPIKE : USNO-B1.0 diffraction spike bit set 04000 = TYCONF : Tycho2 confusion flag set 08000 = BSCONF : Bright star has nearby faint source 10000 = BSART : Faint source is bright star artifact 20000 = USEME : Recommended astrometric standard * = one of SPIKE|YCONF|BSCONF|BSART|XRBIT|ITMBIT|IUCBIT|ITYBIT set R = USEME (recommended astrometric standard)
History: Prepared by Dave Monet. Acknowledgements: It is a pleasure to thank Dave Monet who forwarded a copy of the NOMAD catalog to CDS.
(End) Francois Ochsenbein [CDS] 09-Nov-2005
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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