J/A+A/444/941 Effective temperature of B stars (Paunzen+, 2005)
An empirical temperature calibration for the Δa photometric system.
I. The B-type stars.
Paunzen E., Schnell A., Maitzen H.M.
<Astron. Astrophys., 444, 941-946 (2005)>
=2005A&A...444..941P 2005A&A...444..941P
ADC_Keywords: Stars, B-type ; Effective temperatures ; Photometry
Keywords: stars: chemically peculiar - stars: early-type -
techniques: photometric
Abstract:
We establish an empirical effective temperature calibration of main
sequence, luminosity class V to III B-type stars for the Delta a
photometric system which was originally developed to detect magnetic
chemically peculiar objects of the upper main sequence (early B-type
to early F-type) at 5200A. However, this system provides the index
g1-y which shows an excellent correlation with B-V as well as b-y and
can be used as an indicator of the effective temperature. This is
supplemented by a very accurate color-magnitude diagram, y or V versus
g1-y, which can be used, for example, to determine the reddening,
distance and age of an open cluster. This makes the Delta a
photometric system an excellent tool to investigate the HR diagram
in more detail. Using the reddening-free parameters and already
established calibrations within the Stromgren uvbybeta, Geneva 7-color
and Johnson UBV systems, a polynomial fit of third degree for the
averaged effective temperatures to the individual (g1-y)0 values was
derived. For this purpose, data from the literature as well as new
observations were taken resulting in 225 suitable bright normal B-type
objects. The statistical mean of the error for this sample is 238K
which is sufficient to investigate the HRD of distant galactic open
clusters as well as extragalactic aggregates in the future.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 76 225 *List of 225 normal type stars used for the
calibration
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Note on table2.dat: see Geneva GCPD/75 for a short description of the
Maitzen photometric system (1976A&A....51..223M 1976A&A....51..223M)
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See also:
J/A+A/391/1039 : Teff of metal-poor A-type stars (Kinman+, 2002)
J/A+A/411/559 : Teff for 181 F-K dwarfs (Kovtyukh+, 2003)
J/A+A/429/235 : Teff of 119 C-rich giants (Bergeat+, 2005)
J/A+A/442/281 : Late-type giants BVRIJHKL and Teff calibration
(Kucinskas+, 2005)
J/A+AS/117/227 : Dwarf effective temperatures (Alonso+ 1996)
J/A+AS/122/131 : Delta Scuti rotational velocities and Teff (Solano+ 1997)
J/ApJ/626/446 : Teff scale of FGK stars (Ramirez+, 2005)
J/other/BSAO/38.152 : Teff of CP stars (Glagolevskij 1994)
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- 11 I4 --- HR HR number
13- 19 F7.3 mag Vmag V magnitude
20- 26 F7.3 mag u-b Stroemgren u-b colour index
27- 33 F7.3 mag X Geneva reddenning-free parameter X
34- 40 F7.3 mag (B-V)0 (B-V)0 colour index
41- 47 F7.3 mag (g1-y)0 (g1-y)0 colour index
48- 53 I6 K Teff Adopted effective temperature
55- 58 I4 K e_Teff Error of the adopted Teff
60- 71 A12 --- SpType MK spectral type
72- 76 I5 km/s vsini ?=-99 vsini (1)
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Note (1): Magic number -99 mean no available data
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Acknowledgements: Ernst Paunzen, ernst.paunzen(at)univie.ac.at
History:
* 17-Dec-2005: Original version
* 13-Sep-2006: V magnitude of HD 62578 corrected into 5.572
(email from author)
(End) E. Paunzen (IfA, Vienna), Patricia Vannier [CDS] 17-Dec-2005