Accurate Fundamental Parameters or A, F, and G-type Supergiants in the Solar Neighbourhood

Abstract

The following parameters are determined for 63 Galactic supergiants in the solar neighbourhood: effective temperature Teff, surface gravity log g, iron abundance log e(Fe), microturbulent parameter Vt, mass M/Msun, age t and distance d. A significant improvement in the accuracy of the determination of log g and, all parameters dependent on it, is obtained through application of van Leeuwens (2007) re-reduction of the Hipparcos parallaxes. The typical error in the log g values is now +-0.06 dex for supergiants with distances d < 300 pc and +-0.12 dex for supergiants with d between 300 and 700 pc; the mean error in Teff for these stars is +-120 K. For supergiants with d > 700 pc parallaxes are uncertain or unmeasurable, so typical errors in their log g values are 0.2-0.3 dex. A new Teff scale for A5-G5 stars of luminosity classes Ib-II is presented. Spectral subtypes and luminosity classes of several stars are corrected. Combining the Teff and log g with evolutionary tracks, stellar masses and ages are determined; a majority of the sample has masses between 4 Msun and 15 Msun and, hence, their progenitors were early to middle B-type main sequence stars. Using Fe ii lines, which are insensitive to departures from LTE, the microturbulent parameter Vt and the iron abundance log e(Fe) are determined from high-resolution spectra. The parameter Vt is correlated with gravity: Vt increases with decreasing log g. The mean iron abundance for the 48 supergiants with distances d < 700 pc is log e(Fe)=7.48+-0.09, a value close to the solar value of 7.45+-0.05, and thus the local supergiants and the Sun have the same metallicity.

12 pages, 9 figures. Will be published at MNRAS

References in corpus (7)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• Both accurate and precise gf-values for FeII lines
• Reddenings of FGK supergiants and classical Cepheids from spectroscopic data
• Effects of Galactic fountains and delayed mixing in the chemical evolution of the Milky Way
• Supergiant Temperatures and Linear Radii from Near-Infrared Interferometry
• Quantitative spectroscopy of Deneb
• Sulfur Abundances in the Orion Association B Stars

Cited by in corpus (36)

• Stellar population models in the UV: I. Characterisation of the New Generation Stellar Library
• Spectral and spatial imaging of the Be+sdO binary phi Persei
• Systematic detection of magnetic fields in massive, late-type supergiants
• Fluctuations and Flares in the Ultraviolet Line Emission of Cool Stars: Implications for Exoplanet Transit Observations
• Resolved photometry of extragalactic young massive star clusters
• Stellar population synthesis models between 2.5 and 5 μm based on the empirical IRTF stellar library
• Quantitative spectroscopy of Galactic BA-type supergiants. I. Atmospheric parameters
• The Infrared Telescope Facility (IRTF) spectral library: spectral diagnostics for cool stars
• APOGEE Net: An expanded spectral model of both low mass and high mass stars
• Carbon abundance and the N/C ratio in atmospheres of A-, F- and G-type supergiants and bright giants
• On the neutron-capture elements across the Galactic thin disk using Cepheids
• CRIRES-POP: A library of high resolution spectra in the near-infrared
• First results from the LIFE project: discovery of two magnetic hot evolved stars
• Lithium abundance in atmospheres of F- and G-type supergiants and bright giants
• Accurate luminosities from the oxygen 7771-4 A triplet and the fundamental parameters of F-G supergiants
• The Abundance of Fluorine in Normal G and K Stars of the Galactic Thin Disk
• Carbon, Nitrogen and Oxygen Abundances in Atmospheres of the 5-11 M B-type Main Sequence Stars
• Spatially resolving the outer atmosphere of the M giant BK Vir in the CO first overtone lines with VLTI/AMBER
• Stellar atmospheric parameters of FGK-type stars from high-resolution optical and near-infrared CARMENES spectra
• Oxygen abundance and the N/C vs N/O relation for AFG supergiants and bright giants
• Detection of the 128 day radial velocity variations in the supergiant α Persei. Rotational modulations, pulsations, or a planet?
• Effective Temperature Estimations from Line Depth Ratios in the \H\ and \K-band Spectra of IGRINS
• Nitrogen Enrichment in Atmospheres of A- and F- Type Supergiants
• Possible Overionization of C II, N II, and O II Ions in the Atmospheres of Early B- and Late O-Type Stars
• A catalogue of Paschen-line profiles in standard stars
• Determining the effective temperatures of G- and K-type giants and supergiants based on observed photometric indices
• Influence of departures from LTE on determinations of the sulfur abundances in A-K type stars
• The Cool Giant HD 77361 - A Super Li-Rich Star
• Three nearby K-giants with planets: Accurate determination of basic parameters, including an analysis of metallicity based on Fe I lines
• One of Everything: The Breakthrough Listen Exotica Catalog
• The evolution of magnetic fields in hot stars
• Analysis of the non-LTE lithium abundance for a large sample of F-, G-, and K-giants and supergiants
• Micro-turbulence across the Hertzsprung-Russell diagram. Observational constrains for stars in the MW
• CoronaGraph Instrument Reference stars for Exoplanets (CorGI-REx) I. Preliminary Vetting and Implications for the Roman Coronagraph and Habitable Worlds Observatory
• Better Alternative to "Astronomical Silicate": Laboratory-Based Optical Functions of Chondritic/Solar Abundance Glass With Application to HD161796
• Eighteen Exoplanet Host Stars from the NPOI Data Archive