Low-frequency photospheric and wind variability in the early-B supergiant HD 2905

Abstract

Despite the important advances in space asteroseismology during the last decade, the early phases of evolution of stars with masses above $\sim$15 M${}_{\odot }$ have been only vaguely explored up to now. Our goal is to detect, analyze and interpret variability in the early-B type supergiant HD\,2905 using long-term, ground based, high resolution spectroscopy. We gather a total of 1141 high-resolution spectra covering some 2900 days. We complement these observations with the $Hipparcos$ light curve, which includes 160 data points obtained during a time span of $\sim$1200 days. We investigate spectroscopic variability of up to 12 diagnostic lines by using the zero and first moments of the line profiles. We perform a frequency analysis of both the spectroscopic and photometric dataset. HD\,2905 is a spectroscopic variable with peak-to-peak amplitudes in the zero and first moments of the photospheric lines of up to 15\% and 30 \kms, respectively. The amplitude of the line-profile variability is correlated with the line formation depth in the photosphere and wind. All investigated lines present complex temporal behavior indicative of multi-periodic variability with timescales of a few days to several weeks. The Scargle periodograms of the {\it Hipparcos\} light curve and the first moment of purely photospheric lines reveal a low-frequency amplitude excess and a clear dominant frequency at $\sim$0.37 d${}^{-1}$. In the spectroscopy, several additional frequencies are present in the range 0.1 - 0.4 d${}^{-1}$. These may be associated with heat-driven gravity modes, convectively-driven gravity waves, or sub-surface convective motions. Additional frequencies are detected below 0.1 d${}^{-1}$. In the particular case of H$\alpha$, these are produced by rotational modulation of a non-spherically symmetric stellar wind.

Accepted for publication in A&A. 13 figures, 2 tables

References in corpus (10)

• Quantitative studies of the optical and UV spectra of Galactic early B supergiants I. Fundamental parameters
• Statistical properties of a sample of periodically variable B-type supergiants - Evidence for opacity-driven gravity-mode oscillations
• Most Detects G- and P-Modes in the B Supergiant HD 163899 (B2Ib/II)
• First Results From The Hertzsprung Song Telescope: Asteroseismology Of The G5 Subgiant Star {\Mu}Her
• On the use of the Fourier Transform to determine the projected rotational velocity of line-profile variable B stars
• The Most Massive Heartbeat: An In-depth Analysis of ι Orionis
• LMC Blue Supergiant Stars and the Calibration of the Flux-weighted Gravity--Luminosity Relationship
• Discovery of the new slowly pulsating B star HD 163830 (B5II/III) from MOST spacebased photometry
• Radial dependence of line profile variability in seven O9--B0.5 stars
• Wind structure of late B supergiants I. Multi-line analyses of near-surface and wind structure in HD 199 478 (B8 Iae)

Cited by in corpus (26)

• Low-frequency gravity waves in blue supergiants revealed by high-precision space photometry
• Variability of OB stars from TESS southern Sectors 1-13 and high-resolution IACOB and OWN spectroscopy
• Photometric detection of internal gravity waves in upper main-sequence stars. II. Combined TESS photometry and high-resolution spectroscopy
• On the photometric detection of Internal Gravity Waves in upper main-sequence stars I. Methodology and application to CoRoT targets
• Diverse Variability of O and B Stars Revealed from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection of an Asteroseismic Sample
• K2 space photometry reveals rotational modulation and stellar pulsations in chemically peculiar A and B stars
• Stochastic Low Frequency Variability in 3-Dimensional Radiation Hydrodynamical Models of Massive Star Envelopes
• The CubeSpec space mission. I. Asteroseismology of massive stars from time series optical spectroscopy: science requirements and target list prioritisation
• The VLT-FLAMES Tarantula Survey: XXVIII. Nitrogen abundances for apparently single dwarf and giant B-type stars with small projected rotational velocities
• Stochastic light variations in hot stars from wind instability: Finding photometric signatures and testing against the TESS data
• Light variations due to the line-driven wind instability and wind blanketing in O stars
• MONOS.II. Orbit review and analysis for 35 single-lined spectroscopic binary systems and candidates
• High-resolution spectroscopic study of massive blue and red supergiants in Per OB1
• On The Impact Of 22Ne On The Pulsation Periods Of Carbon-Oxygen White Dwarfs With Helium Dominated Atmospheres
• Characterization of the variability in the O+B eclipsing binary HD 165246
• A modern guide to quantitative spectroscopy of massive OB stars
• Three Dimensional Natures of Massive Star Envelopes
• Synthesizing Spectra from 3D Radiation Hydrodynamic Models of Massive Stars Using Monte Carlo Radiation Transport
• Variability of massive stars in M31 from the Palomar Transient Factory
• The ESO UVES/FEROS Large Programs of TESS OB pulsators. I. Global stellar parameters from high-resolution spectroscopy
• Similar but different: the varied landscape of Onfp/Oef stars variability
• Magnetic characterization and variability study of the magnetic SPB star o Lup
• Fast time optical variability in Be/X-ray binaries. Pulsation and rotation
• The nature of the Cygnus extreme B-supergiant 2MASS J20395358+4222505
• Variability of Galactic blue supergiants observed with TESS
• Fast optical variability in Supergiant X-ray binaries