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J/AJ/127/2838   Faint high-latitude carbon stars SDSS photometry (Downes+, 2004)

Faint high-latitude carbon stars discovered by the Sloan Digital Sky Survey: an initial catalog. Downes R.A., Margon B., Anderson S.F., Harris H.C., Knapp G.R., Schroeder J., Schneider D.P., York D.G., Pier J.R., Brinkmann J. <Astron. J., 127, 2838-2849 (2004)> =2004AJ....127.2838D
ADC_Keywords: Stars, carbon ; Stars, faint ; Photometry, SDSS ; Photometry, infrared Keywords: astrometry - stars: carbon - stars: statistics - surveys Abstract: A search of more than 3000deg2 of high-latitude sky by the Sloan Digital Sky Survey has yielded 251 faint high-latitude carbon stars (FHLCs), the large majority previously uncatalogued. We present homogeneous spectroscopy, photometry, and astrometry for the sample. The objects lie in the 15.6<r<20.8 range and exhibit a wide variety of apparent photospheric temperatures, ranging from spectral types near M to as early as F. Proper-motion measurements for 222 of the objects show that at least 50%, and quite probably more than 60%, of these objects are actually low-luminosity dwarf carbon (dC) stars, in agreement with a variety of recent, more limited investigations that show that such objects are the numerically dominant type of star with C2 in the spectrum. This SDSS homogeneous sample of ∼110 dC stars now constitutes 90% of all known carbon dwarfs and will grow by another factor of 2-3 by the completion of the survey. As the spectra of the dC and the faint halo giant C stars are very similar (at least at spectral resolution of 103), despite a difference of 10mag in luminosity, it is imperative that simple luminosity discriminants other than proper motion be developed. We use our enlarged sample of FHLCs to examine a variety of possible luminosity criteria, including many previously suggested, and find that, with certain important caveats, JHK photometry may segregate dwarfs and giants. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 103 251 Faint High-Latitude Carbon Stars Discovered in SDSS
See also: : the SDSS Catalog Home Page J/AJ/126/2579 : SDSS quasar catalog. II. First data release (Schneider+, 2003) J/AJ/124/1651 : Faint high-latitude carbon stars SDSS photometry (Margon+ 2002) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS name (1) 26- 32 F7.2 --- Epoch ? Epoch of the observation (2) 34- 38 F5.2 mag rmag SDSS r-band magnitude (3) 39 A1 --- f_rmag [gh] Flag on rmag (4) 41- 44 F4.2 mag u-g ? SDSS (u-g) color 46- 49 F4.2 mag g-r ? SDSS (g-r) color 51- 54 F4.2 mag r-i ? SDSS (r-i) color 56- 60 F5.2 mag i-z ? SDSS (i-z) color 62- 66 F5.2 mag J-H ? The (J-H) color 68- 72 F5.2 mag H-K ? The (H-K) color 74- 77 F4.2 mag r-J ? The (r-J) color 79- 83 F5.1 mas/yr mu ? Proper motion 85- 88 F4.1 mas/yr e_mu ? The 1 σ error in mu 90- 94 F5.1 deg PA ? Position angle 96 A1 --- Class Object class (5) 98- 99 I2 --- f_Class ? Flag on Class (6)
Note (1): As per normal convention, coordinate names are truncated rather than rounded; precise astrometry is available in the SDSS archive. Note (2): Epochs provided for those objects with proper motions detected with 3 σ or greater significance. Note (3): An approximate transformation to the Cousins I magnitude, derived empirically from a comparison of SDSS observations of multiple standard stars with published broadband photometry (Grebel, 2004, Priv. Comm.), is Ic=-0.333(r-i) + i - 0.443. Note that this transformation is not optimized for the specific case of C stars. Note (4): Flag on rmag as follows: g = Poor photometry: gmag given for crude guidance; h = Poor photometry. Note (5): Object class takes the following values: D = Dwarf; G = Giant; U = Uncertain; NULL = No data. Note (6): Flags on Class take the following values: 1 = "F/G carbon star"; 2 = Possible "F/G carbon star"; 3 = Poorly calibrated spectrum; 4 = FASST 2; see Hendon & Stone, 1998, Cat. J/AJ/115/296 5 = RASS and FIRST source nearby; 6 = LP 587-45; 7 = Composite; 8 = Variable?; 9 = Candidate extragalactic object (see Paper I, Margon et al., Cat. J/AJ/124/1651); 10 = N-type; see Totten & Irwin (1998MNRAS.294....1T) and Hendon & Stone , 1998, Cat. J/AJ/115/296 11 = RASS source (QSO) nearby; 12 = In Draco dwarf galaxy (BASV 461); 13 = In Draco dwarf galaxy (Draco C-1); symbiotic variable; ROSAT source; 14 = In Draco dwarf galaxy (BASV 578); 15 = In Draco dwarf galaxy?
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 08-Jul-2004
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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