J/ApJ/634/451 Interstellar Ca II line equivalent widths (Megier+, 2005)
Interstellar Ca II line intensities and the distances of the OB stars.
Megier A., Strobel A., Bondar A., Musaev F.A., Han I., Krelowski J.,
Galazutdinov G.A.
<Astrophys. J., 634, 451-458 (2005)>
=2005ApJ...634..451M 2005ApJ...634..451M (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Equivalent widths ; Stars, distances ;
Stars, early-type
Keywords: ISM: lines and bands - stars: distances - stars: early-type
Abstract:
We show that the equivalent widths of the well-known interstellar CaII
H and K lines can be used to determine the distances to OB stars in
our Galaxy. The equivalent widths, measured in the spectra of 147
early-type stars, are strongly related to the Hipparcos parallaxes of
those objects. The lines fitted to the parallax-equivalent width data
are given by the formulae π=1/[2.78EW(K)+95] and
π=1/[4.58EW(H)+102], where π is in arcseconds and EW is in
milliangstroms.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 75 147 Target Data
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD number
8- 15 A8 --- SpType MK spectral type and luminosity class
17- 20 F4.2 mag E(B-V) Reddening
22- 26 F5.2 arcsec plx Parallax
28- 31 F4.2 arcsec e_plx Error in plx
33- 37 F5.1 0.1pm EW(CaIIK) ? CaII K line equivalent width
38 A1 --- u_EW(CaIIK) [:!] Uncertainty flag on EW(CaIIK)
40- 43 F4.1 0.1pm e_EW(CaIIK) ? Error in EW(CaIIK)
45- 49 F5.1 0.1pm EW(CaIIH) ? CaII H line equivalent width
51- 54 F4.1 0.1pm e_EW(CaIIH) ? Error in EW(CaIIH)
56- 60 F5.1 0.1pm EW(KI) ? KI line equivalent width
62- 65 F4.1 0.1pm e_EW(KI) ? Error in EW(KI)
67- 70 F4.1 0.1pm EW(CH) ? CH line equivalent width
72- 75 F4.1 0.1pm e_EW(CH) ? Error in EW(CH)
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History:
From electronic version of the journal
(End) Marianne Brouty [CDS] 03-Aug-2006