Rotational modulation of the photospheric and chromospheric activity in the young, single K2-dwarf PW And

J. López-Santiago, D. Montes, M. J. Fernández-Figueroa, Lawrence William Ramsey

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

High resolution echelle spectra of PW And (HD 1405) have been taken during eight observing runs from 1999 to 2002. The detailed analysis of the spectra allow us to determine its spectral type (K2V), mean heliocentric radial velocity (Vhel = -11.15 km s-1) rotational velocity (v sin i = 22.6 km s-1), and equivalent width of the lithium line λ6707.8 Å (EW(Li I) = 273 mÅ). The kinematic (Galactic Velocity (U,V,W)) confirms its membership in the Local Association moving group, in agreement with the age (30 to 80 Myrs) inferred from the color magnitude diagram and the lithium equivalent width. Photospheric activity (presence of cool spots that disturb the profiles of the photospheric lines) has been detected as changes in the bisectors of the cross correlation function (CCF) resulting of cross-correlate the spectra of PW And with the spectrum of a non-active star of similar spectral type. These variations of the CCF bisectors are related to the variations in the measured radial velocities and are modulated with a period similar to the photometric period of the star. At the same time, chromospheric activity has been analyzed, using the spectral subtraction technique and simultaneous spectroscopic observations of the Hα, Hβ, Na I D1 and D2, He I D3, Mg I b triplet, Ca II H&K, and Ca II infrared triplet lines. A flare was observed during the last observing run of 2001, showing an enhancement in the observed chromospheric lines. A less powerful flare was observed on 2002 August 23. The variations of the chromospheric activity indicators seem to be related to the photospheric activity. A correlation between radial velocity, changes in the CCF bisectors and equivalent width of different chromospheric lines is observed with a different behaviour between epochs 1999, 2001 and 2002.

Original languageEnglish (US)
Pages (from-to)489-502
Number of pages14
JournalAstronomy and Astrophysics
Volume411
Issue number3
DOIs
StatePublished - Dec 1 2003

Fingerprint

radial velocity
cross correlation
modulation
flares
lithium
stars
color-magnitude diagram
subtraction
kinematics
time measurement
diagram
young
augmentation
high resolution
profiles

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

López-Santiago, J. ; Montes, D. ; Fernández-Figueroa, M. J. ; Ramsey, Lawrence William. / Rotational modulation of the photospheric and chromospheric activity in the young, single K2-dwarf PW And. In: Astronomy and Astrophysics. 2003 ; Vol. 411, No. 3. pp. 489-502.
@article{9f214e3fb7f148118904c8b52dee489f,
title = "Rotational modulation of the photospheric and chromospheric activity in the young, single K2-dwarf PW And",
abstract = "High resolution echelle spectra of PW And (HD 1405) have been taken during eight observing runs from 1999 to 2002. The detailed analysis of the spectra allow us to determine its spectral type (K2V), mean heliocentric radial velocity (Vhel = -11.15 km s-1) rotational velocity (v sin i = 22.6 km s-1), and equivalent width of the lithium line λ6707.8 {\AA} (EW(Li I) = 273 m{\AA}). The kinematic (Galactic Velocity (U,V,W)) confirms its membership in the Local Association moving group, in agreement with the age (30 to 80 Myrs) inferred from the color magnitude diagram and the lithium equivalent width. Photospheric activity (presence of cool spots that disturb the profiles of the photospheric lines) has been detected as changes in the bisectors of the cross correlation function (CCF) resulting of cross-correlate the spectra of PW And with the spectrum of a non-active star of similar spectral type. These variations of the CCF bisectors are related to the variations in the measured radial velocities and are modulated with a period similar to the photometric period of the star. At the same time, chromospheric activity has been analyzed, using the spectral subtraction technique and simultaneous spectroscopic observations of the Hα, Hβ, Na I D1 and D2, He I D3, Mg I b triplet, Ca II H&K, and Ca II infrared triplet lines. A flare was observed during the last observing run of 2001, showing an enhancement in the observed chromospheric lines. A less powerful flare was observed on 2002 August 23. The variations of the chromospheric activity indicators seem to be related to the photospheric activity. A correlation between radial velocity, changes in the CCF bisectors and equivalent width of different chromospheric lines is observed with a different behaviour between epochs 1999, 2001 and 2002.",
author = "J. L{\'o}pez-Santiago and D. Montes and Fern{\'a}ndez-Figueroa, {M. J.} and Ramsey, {Lawrence William}",
year = "2003",
month = "12",
day = "1",
doi = "10.1051/0004-6361:20031377",
language = "English (US)",
volume = "411",
pages = "489--502",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
number = "3",

}

Rotational modulation of the photospheric and chromospheric activity in the young, single K2-dwarf PW And. / López-Santiago, J.; Montes, D.; Fernández-Figueroa, M. J.; Ramsey, Lawrence William.

In: Astronomy and Astrophysics, Vol. 411, No. 3, 01.12.2003, p. 489-502.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Rotational modulation of the photospheric and chromospheric activity in the young, single K2-dwarf PW And

AU - López-Santiago, J.

AU - Montes, D.

AU - Fernández-Figueroa, M. J.

AU - Ramsey, Lawrence William

PY - 2003/12/1

Y1 - 2003/12/1

N2 - High resolution echelle spectra of PW And (HD 1405) have been taken during eight observing runs from 1999 to 2002. The detailed analysis of the spectra allow us to determine its spectral type (K2V), mean heliocentric radial velocity (Vhel = -11.15 km s-1) rotational velocity (v sin i = 22.6 km s-1), and equivalent width of the lithium line λ6707.8 Å (EW(Li I) = 273 mÅ). The kinematic (Galactic Velocity (U,V,W)) confirms its membership in the Local Association moving group, in agreement with the age (30 to 80 Myrs) inferred from the color magnitude diagram and the lithium equivalent width. Photospheric activity (presence of cool spots that disturb the profiles of the photospheric lines) has been detected as changes in the bisectors of the cross correlation function (CCF) resulting of cross-correlate the spectra of PW And with the spectrum of a non-active star of similar spectral type. These variations of the CCF bisectors are related to the variations in the measured radial velocities and are modulated with a period similar to the photometric period of the star. At the same time, chromospheric activity has been analyzed, using the spectral subtraction technique and simultaneous spectroscopic observations of the Hα, Hβ, Na I D1 and D2, He I D3, Mg I b triplet, Ca II H&K, and Ca II infrared triplet lines. A flare was observed during the last observing run of 2001, showing an enhancement in the observed chromospheric lines. A less powerful flare was observed on 2002 August 23. The variations of the chromospheric activity indicators seem to be related to the photospheric activity. A correlation between radial velocity, changes in the CCF bisectors and equivalent width of different chromospheric lines is observed with a different behaviour between epochs 1999, 2001 and 2002.

AB - High resolution echelle spectra of PW And (HD 1405) have been taken during eight observing runs from 1999 to 2002. The detailed analysis of the spectra allow us to determine its spectral type (K2V), mean heliocentric radial velocity (Vhel = -11.15 km s-1) rotational velocity (v sin i = 22.6 km s-1), and equivalent width of the lithium line λ6707.8 Å (EW(Li I) = 273 mÅ). The kinematic (Galactic Velocity (U,V,W)) confirms its membership in the Local Association moving group, in agreement with the age (30 to 80 Myrs) inferred from the color magnitude diagram and the lithium equivalent width. Photospheric activity (presence of cool spots that disturb the profiles of the photospheric lines) has been detected as changes in the bisectors of the cross correlation function (CCF) resulting of cross-correlate the spectra of PW And with the spectrum of a non-active star of similar spectral type. These variations of the CCF bisectors are related to the variations in the measured radial velocities and are modulated with a period similar to the photometric period of the star. At the same time, chromospheric activity has been analyzed, using the spectral subtraction technique and simultaneous spectroscopic observations of the Hα, Hβ, Na I D1 and D2, He I D3, Mg I b triplet, Ca II H&K, and Ca II infrared triplet lines. A flare was observed during the last observing run of 2001, showing an enhancement in the observed chromospheric lines. A less powerful flare was observed on 2002 August 23. The variations of the chromospheric activity indicators seem to be related to the photospheric activity. A correlation between radial velocity, changes in the CCF bisectors and equivalent width of different chromospheric lines is observed with a different behaviour between epochs 1999, 2001 and 2002.

UR - http://www.scopus.com/inward/record.url?scp=10744219741&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=10744219741&partnerID=8YFLogxK

U2 - 10.1051/0004-6361:20031377

DO - 10.1051/0004-6361:20031377

M3 - Article

VL - 411

SP - 489

EP - 502

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

IS - 3

ER -