Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2009-06-30
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
11 pages, 9 figures ; accepted by Astronomy and Astrophysics
Scientific paper
We report the detection of an unusually high lithium content in HD 232862, a field giant classified as a G8II star, and hosting a magnetic field. With the spectropolarimeters ESPaDOnS at CFHT and NARVAL at TBL, we have collected high resolution and high signal-to-noise spectra of three giants : HD 232862, KU Peg and HD 21018. From spectral synthesis we have inferred stellar parameters and measured lithium abundances that we have compared to predictions from evolutionary models. We have also analysed Stokes V signatures, looking for a magnetic field on these giants. HD 232862, presents a very high abundance of lithium (ALi = 2.45 +/- 0.25 dex), far in excess of the theoretically value expected at this spectral type and for this luminosity class (i.e, G8II). The evolutionary stage of HD 232862 has been precised, and it suggests a mass in the lower part of the [1.0 Msun ; 3.5 Msun ] mass interval, likely 1.5 to 2.0 solar mass, at the bottom of the Red Giant Branch. Besides, a time variable Stokes V signature has been detected in the data of HD 232862 and KU Peg, pointing to the presence of a magnetic field at the surface of these two rapidly rotating active stars.
Auriere Michel
de Laverny Patrick
de Medeiros Jose Renan
Kolev D.
Konstantinova-Antova Renada
No associations
LandOfFree
Lithium and magnetic fields in giants. HD 232862 : a magnetic and lithium-rich giant star does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Lithium and magnetic fields in giants. HD 232862 : a magnetic and lithium-rich giant star, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lithium and magnetic fields in giants. HD 232862 : a magnetic and lithium-rich giant star will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-441055