J/A+A/428/149 Hipparcos parallaxes of O stars (Schroeder+, 2004)
On the Hipparcos parallaxes of O stars.
Schroeder S.E., Kaper L., Lamers H.J.G.L.M., Brown A.G.A.
<Astron. Astrophys., 428, 149-157 (2004)>
=2004A&A...428..149S 2004A&A...428..149S
ADC_Keywords: Stars, O ; Parallaxes, trigonometric ; Magnitudes, absolute ;
MK spectral classification
Keywords: astrometry - stars: early-type - stars: fundamental parameters -
stars: statistics
Abstract:
We compare the absolute visual magnitude of the majority of bright
O stars in the sky as predicted from their spectral type with the
absolute magnitude calculated from their apparent magnitude and the
Hipparcos parallax. We find that many stars appear to be much fainter
than expected, up to five magnitudes.
We find no evidence for a correlation between magnitude differences
and the stellar rotational velocity as suggested for OB stars by
Lamers et al. (1997A&A...325L..25L 1997A&A...325L..25L), whose small sample of stars is
partly included in ours.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 54 154 Characteristics of the O star sample.
table2.dat 45 8 Characteristics of the B stars in the sample of Lamers
et al., 1997A&A...325L..25L 1997A&A...325L..25L depicted in Fig. 5.
refs.dat 43 14 References
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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- 25 A18 --- SpType MK spectral type
27 I1 --- r_SpType Reference for SpType, when not
Mason et al., 1998AJ....115..821M 1998AJ....115..821M
29- 33 F5.2 mas plx Hipparcos parallax, corrected for
interstellar extinction (AV)
35- 38 F4.2 mas e_plx rms uncertainty on plx
40- 43 F4.2 mag AV Interstellar extinction
45- 49 F5.1 mag VMAGH ? Hipparcos absolute magnitude
51- 54 F4.1 mag VMAGSK Predicted absolute magnitude, derived from the
spectral type according to the calibration of
Schmidt-Kaler et al. (G1)
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Byte-by-byte Description of file: table2.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
19- 23 F5.2 mas plx Hipparcos parallax, corrected for
interstellar extinction (AV) and the presence
of spectroscopic companions.
25- 28 F4.2 mas e_plx rms uncertainty on plx
30- 33 F4.1 mag VMAGH ? Hipparcos absolute magnitude
35- 38 F4.1 mag VMAGSK Predicted absolute magnitude, derived from the
spectral type according to the calibration of
Schmidt-Kaler et al. (G1) (1)
40- 42 I3 km/s vsini Rotation velocity
44- 45 I2 --- r_SpType ? Reference for SpType and vsini
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Note (1): If necessary through interpolation (note that they have a special
section for Be stars).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode BibCode
24- 43 A20 --- Aut Author's name
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Global notes:
Note (G1): Schmidt-Kaler et al., 1982, Landolt-Boernstein: Numerical Data
and Functional Relationships in Science and Technology - New Series,
Group VI: Astronomy and Astrophysics, Volume 2b, Schaifers/Voigt,
Astronomy and Astrophysics, Stars and Star Clusters
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Sep-2005