The Wilson-Bappu effect of the MgII k line - dependence on stellar temperature, activity and metallicity

O. Elgaroy, O. Engvold, Niels Lund

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The Wilson-Bappu effect is investigated using accurate absolute magnitudes of 65 stars obtained through early release of data from the Hipparcos satellite together with MgII k fine widths determined from high resolution spectra observed with the International Ultraviolet Explorer (IUE) observatory. Stars of spectral classes F, G, K and M and luminosity classes I-V are represented in the sample. Wilson-Bappu relations for the Mg II k line for stars of different temperatures i.e. spectral classes are determined. The relation varies with spectral class and there is a significant scatter of the line widths around the regression lines. The sample contains slowly rotating stars of different activity levels and is suitable for investigations of a possible relation between line width and stellar activity. A difference in behavior between dwarfs and giants (and supergiants) of spectral class K seems to be present. Magnetic activity affects the width of the Mg II k line in dwarfs. Metallicity is found to influence the Mg II k line width in giants and supergiants. Possible interpretations of the new results are briefly discussed.
Original languageEnglish
JournalAstronomy and Astrophysics
Volume343
Issue number1
Pages (from-to)222-228
ISSN0004-6361
Publication statusPublished - 1999

Keywords

  • stars : activity
  • stars : chromospheres

Cite this

@article{53088f26acc444539402e9ac02056749,
title = "The Wilson-Bappu effect of the MgII k line - dependence on stellar temperature, activity and metallicity",
abstract = "The Wilson-Bappu effect is investigated using accurate absolute magnitudes of 65 stars obtained through early release of data from the Hipparcos satellite together with MgII k fine widths determined from high resolution spectra observed with the International Ultraviolet Explorer (IUE) observatory. Stars of spectral classes F, G, K and M and luminosity classes I-V are represented in the sample. Wilson-Bappu relations for the Mg II k line for stars of different temperatures i.e. spectral classes are determined. The relation varies with spectral class and there is a significant scatter of the line widths around the regression lines. The sample contains slowly rotating stars of different activity levels and is suitable for investigations of a possible relation between line width and stellar activity. A difference in behavior between dwarfs and giants (and supergiants) of spectral class K seems to be present. Magnetic activity affects the width of the Mg II k line in dwarfs. Metallicity is found to influence the Mg II k line width in giants and supergiants. Possible interpretations of the new results are briefly discussed.",
keywords = "stars : activity, stars : chromospheres",
author = "O. Elgaroy and O. Engvold and Niels Lund",
year = "1999",
language = "English",
volume = "343",
pages = "222--228",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",
publisher = "E D P Sciences",
number = "1",

}

The Wilson-Bappu effect of the MgII k line - dependence on stellar temperature, activity and metallicity. / Elgaroy, O.; Engvold, O.; Lund, Niels.

In: Astronomy and Astrophysics, Vol. 343, No. 1, 1999, p. 222-228.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - The Wilson-Bappu effect of the MgII k line - dependence on stellar temperature, activity and metallicity

AU - Elgaroy, O.

AU - Engvold, O.

AU - Lund, Niels

PY - 1999

Y1 - 1999

N2 - The Wilson-Bappu effect is investigated using accurate absolute magnitudes of 65 stars obtained through early release of data from the Hipparcos satellite together with MgII k fine widths determined from high resolution spectra observed with the International Ultraviolet Explorer (IUE) observatory. Stars of spectral classes F, G, K and M and luminosity classes I-V are represented in the sample. Wilson-Bappu relations for the Mg II k line for stars of different temperatures i.e. spectral classes are determined. The relation varies with spectral class and there is a significant scatter of the line widths around the regression lines. The sample contains slowly rotating stars of different activity levels and is suitable for investigations of a possible relation between line width and stellar activity. A difference in behavior between dwarfs and giants (and supergiants) of spectral class K seems to be present. Magnetic activity affects the width of the Mg II k line in dwarfs. Metallicity is found to influence the Mg II k line width in giants and supergiants. Possible interpretations of the new results are briefly discussed.

AB - The Wilson-Bappu effect is investigated using accurate absolute magnitudes of 65 stars obtained through early release of data from the Hipparcos satellite together with MgII k fine widths determined from high resolution spectra observed with the International Ultraviolet Explorer (IUE) observatory. Stars of spectral classes F, G, K and M and luminosity classes I-V are represented in the sample. Wilson-Bappu relations for the Mg II k line for stars of different temperatures i.e. spectral classes are determined. The relation varies with spectral class and there is a significant scatter of the line widths around the regression lines. The sample contains slowly rotating stars of different activity levels and is suitable for investigations of a possible relation between line width and stellar activity. A difference in behavior between dwarfs and giants (and supergiants) of spectral class K seems to be present. Magnetic activity affects the width of the Mg II k line in dwarfs. Metallicity is found to influence the Mg II k line width in giants and supergiants. Possible interpretations of the new results are briefly discussed.

KW - stars : activity

KW - stars : chromospheres

M3 - Journal article

VL - 343

SP - 222

EP - 228

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

IS - 1

ER -