The stellar temperature scale for stars of spectral types from O8 to F6 and the standard deviation of the MK spectral classification

1991 ◽  
Vol 183 (1) ◽  
pp. 91-115 ◽  
Author(s):  
E. Theodossiou ◽  
E. Danezis
Keyword(s):  
Standard Deviation ◽  
Temperature Scale ◽  
Spectral Classification ◽  
Stellar Temperature

scholarly journals The properties of early-type stars in the Magellanic Clouds

2008 ◽  
Vol 4 (S256) ◽  
pp. 325-336
Author(s):  
Christopher J. Evans
Keyword(s):  
Physical Properties ◽  
Mass Loss ◽  
Temperature Scale ◽  
Massive Stars ◽  
Magellanic Clouds ◽  
Early Type ◽  
The Past ◽  
The Galaxy ◽  
Stellar Temperature ◽  
Early Type Stars

AbstractThe past decade has witnessed impressive progress in our understanding of the physical properties of massive stars in the Magellanic Clouds, and how they compare to their cousins in the Galaxy. I summarise new results in this field, including evidence for reduced mass-loss rates and faster stellar rotational velocities in the Clouds, and their present-day compositions. I also discuss the stellar temperature scale, emphasizing its dependence on metallicity across the entire upper-part of the Hertzsprung-Russell diagram.

ACCURACY OF OPTICAL PYROMETRY IN THE RANGE 800 °C TO 4000 °C

1958 ◽  
Vol 36 (10) ◽  
pp. 1397-1408 ◽  
Author(s):  
D. R. Lovejoy
Keyword(s):  
Standard Deviation ◽  
Temperature Scale ◽  
Primary Standard ◽  
Secondary Standard ◽  
Optical Pyrometer ◽  
Optical Pyrometry ◽  
International Temperature Scale ◽  
International Temperature ◽  
Carbon Arc ◽  
Temperature Standard

A pair of secondary standard tungsten strip lamps have had a luminance temperature – current calibration, in the range 800 °C to 2200 °C, at a number of national laboratories. An analysis of the calibration results confirms estimates of the accuracy of optical pyrometry in the range 800 °C to 2200 °C and supports the extension of these estimates to 4000 °C. The standard deviation uncertainty of optical pyrometry is shown to be about 1 °C at 800 °C rising to 2 °C at 2200 °C and 10 °C at 4000 °C, being about double this for the calibration of commercial pyrometers unless certain described precautions are taken.The reliability of the secondary standard lamps, when used under well-defined conditions, is confirmed and it is shown that they have a standard deviation calibration uncertainty of about 1 °C for the vacuum-type lamps in the range 800 °C to 1500 °C and 2 °C for the gas-filled lamps in the range 1500 °C to 2200 °C. Most of this uncertainty is due to primary standard optical pyrometer calibration errors. Attention is drawn to the fact that a carbon arc fulfills the requirements of a secondary luminance temperature standard at about 3514 °C.Recent determinations of the gold point and the second radiation constant indicate that the 1948 International Temperature Scale is lower than the thermodynamic scale by an amount varying from 0.8 °C at 800 °C to 12 °C at 4000 °C. This is already greater than the calibration errors of optical pyrometry and, in view of the still greater accuracies presaged by photomultipliers, a revision of the International Temperature Scale is suggested.

scholarly journals The stellar temperature scale from O5 to A0

1970 ◽  
Vol 36 ◽  
pp. 83-89 ◽  
Author(s):  
D.S. Hayes
Keyword(s):  
Wavelength Range ◽  
Temperature Scale ◽  
B Stars ◽  
Stellar Temperature ◽  
The Continuum

An absolute spectrophotometric calibration of Vega and eleven other standard stars was completed by the author in 1967. This calibration extends from 3200 to 10870 Å, and therefore gives a useful calibration of the Paschen discontinuity as well as the Balmer discontinuity, for which calibrations have been available for some time.The measured values of the ratio of the size of the Paschen discontinuity to the size of the Balmer discontinuity have been compared with corresponding values predicted by model atmospheres. The comparison shows that LTE models satisfactorily predict the continuum in the wavelength range given above.A stellar temperature scale has been determined by fitting the measured sizes of the Balmer discontinuity of 43 stars to blanketed model atmospheres. This temperature scale agrees very well with Morton's modified form of the Morton-Adams temperature scale for all except the latest B-stars, for which higher temperatures are predicted.

Narrow-band photometric classification of eclipsing binaries

1966 ◽  
Vol 24 ◽  
pp. 190-210
Author(s):  
D. H. McNamara
Keyword(s):  
Temperature Scale ◽  
Narrow Band ◽  
Eclipsing Binaries ◽  
Spectral Classification ◽  
Uniform System ◽  
Fundamental Properties ◽  
Eclipsing Stars ◽  
Accurate Knowledge ◽  
Observational Program

Although a great deal of work has been devoted in recent years to the problem of improving our knowledge of the spectroscopic and light elements of the eclipsing stars, little effort has been expended on the problem of two-dimensional spectral classification of the component stars on a uniform system. The only serious attempt in this direction appears to be the MK classification of a number of eclipsing stars by Miss Roman (i). Since the light- and velocity-curves of eclipsing systems provide us with fundamental properties such as radii, masses, and densities it is extremely important to have accurate knowledge of the luminosities and spectral types of these objects. In this paper we describe the results of an observational program designed specifically to improve our knowledge of the luminosities and colors of these important stars. The luminosities and colors are then utilized in a discussion of the mass-luminosity relation and effective-temperature scale of stars brigher than the Sun.

scholarly journals The stellar temperature scale from angular diameters and flux distributions

1997 ◽  
Vol 189 ◽  
pp. 147-152
Author(s):  
A.J. Booth
Keyword(s):  
Temperature Scale ◽  
Current Situation ◽  
Stellar Temperature ◽  
Uv Visible ◽  
Effective Temperatures ◽  
Angular Diameters

The current situation for the measurement of effective temperatures from interferometrically determined angular diameters and spectrophometry in the UV, visible and IR is considered. Accuracies and reliabilities of the resulting temperatures are assessed and coverage of stellar types is discussed.

scholarly journals Observations of Strong Stellar Lines with the OAO

1970 ◽  
Vol 36 ◽  
pp. 173-177
Author(s):  
A.D. Code ◽  
R. C. Bless
Keyword(s):  
Preliminary Analysis ◽  
Temperature Scale ◽  
Model Atmosphere ◽  
Astronomical Observatory ◽  
Qualitative Description ◽  
Spectral Interval ◽  
Early Type ◽  
Stellar Temperature ◽  
Early Type Stars

This paper reports on preliminary analysis of spectral scans of early-type stars obtained with the Orbiting Astronomical Observatory. The discussion is confined to the spectra of 50 stars observed with a resolution of approximately 10 Å over the spectral interval from 1050 Å to 2000 Å. Following a qualitative description of the spectra, observed equivalent widths of the Siiv (1400 Å) and Civ (1550 Å) lines are compared with model atmosphere calculations. The results suggest an upward revision of the stellar temperature scale for stars earlier than B3 V.

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