The connection between stellar granulation and oscillation as seen by the Kepler mission

  title={The connection between stellar granulation and oscillation as seen by the Kepler mission},
  author={Thomas Kallinger and Joris De Ridder and Saskia Hekker and Savita Mathur and Beno{\^i}t Mosser and Michael Gruberbauer and R. A. Garc{\'i}a and Christoffer Karoff and J{\'e}r{\^o}me Ballot},
  journal={Astronomy and Astrophysics},
Context. The long and almost continuous observations by Kepler show clear evidence of a granulation background signal in a large sample of stars, which is interpreted as the surface manifestation of convection. It has been shown that its characteristic timescale and rms intensity fluctuation scale with the peak frequency (νmax) of the solar-like oscillations. Various attempts have been made to quantify the observed signal, to determine scaling relations for its characteristic parameters, and to… 

Stellar masses from granulation and oscillations of 23 bright red giants observed by BRITE-Constellation

Context. The study of stellar structure and evolution depends crucially on accurate stellar parameters. The photometry from space telescopes has provided superb data that enabled the asteroseismic

Gaussian process modelling of granulation and oscillations in red giant stars

The analysis of photometric time series in the context of transiting planet surveys suffers from the presence of stellar signals, often dubbed ‘stellar noise’. These signals, caused by stellar

Precise stellar surface gravities from the time scales of convectively driven brightness variations

A novel way to measure surface gravities with accuracies of about 4%.

Metallicity effect on stellar granulation detected from oscillating red giants in open clusters

The effect of metallicity on the granulation activity in stars is still poorly understood. Available spectroscopic parameters from the updated APOGEE-\textit{Kepler} catalog, coupled with

Stellar magnetic activity and variability of oscillation parameters: An investigation of 24 solar-like stars observed by Kepler

Context. The Sun and solar-like stars undergo activity cycles for which the underlying mechanisms are not well understood. The oscillations of the Sun are known to vary with its activity cycle and

Hydrodynamical model atmospheres: Their impact on stellar spectroscopy and asteroseismology of late-type stars

Hydrodynamical, i.e. multi-dimensional and time-dependent, model atmospheres of late-type stars have reached a high level of realism. They are commonly applied in high-fidelity work on stellar

On the Granulation and Irregular Variation of Red Supergiants

The mechanism and characteristics of the irregular variations of red supergiants (RSGs) are studied based on the RSG samples in Small Magellanic Cloud (SMC), Large Magellanic Cloud (LMC) and M31.

The signature of granulation in a solar power spectrum as seen with co5bold

The granulation background seen in the power spectrum of a solar-like oscillator poses a serious challenge for extracting precise and detailed information about the stellar oscillations. Using a 3D

NGC 6819: testing the asteroseismic mass scale, mass loss, and evidence for products of non-standard evolution

We present an extensive peakbagging effort on Kepler data of $\sim$50 red giant stars in the open star cluster NGC 6819. By employing sophisticated pre-processing of the time series and Markov Chain



Stellar granulation as seen in disk-integrated intensity. II. Theoretical scaling relations compared with observations

Context. A large set of stars observed by CoRoT and Kepler shows clear evidence for the presence of a stellar background, which is interpreted to arise from surface convection, i.e., granulation.

Stellar granulation as seen in disk-integrated intensity I. Simplified theoretical modeling

Context. Solar granulation has been known for a long time to be a surface manifestation of convection. The space-borne missions CoRoT and Kepler enable us to observe the signature of this phenomena


Sun-like stars show intensity fluctuations on a number of timescales due to various physical phenomena on their surfaces. These phenomena can convincingly be studied in the frequency spectra of these


The granulation pattern that we observe on the surface of the Sun is due to hot plasma rising to the photosphere where it cools down and descends back into the interior at the edges of granules. This


Stars with spectral types earlier than about F0 on (or close) to the main sequence have long been believed to lack observable surface convection, although evolutionary models of A-type stars do

Mode lifetimes of stellar oscillations - Implications for asteroseismology

Context. Successful inference from asteroseismology relies on at least two factors: that the oscillations in the stars have amplitudes large enough to be clearly observable, and that the oscillations

Asteroseismology of red giants from the first four months of Kepler data: Fundamental stellar parameters

Context. Clear power excess in a frequency range typical for solar-type oscillations in red giants has been detected in more than 1000 stars, which have been observed during the first 138 days of the

Hydrodynamical simulations of convection-related stellar micro-variability. II. The enigmatic granul

We used a series of CO5BOLD hydrodynamical model atmospheres covering stellar objects from white dwarfs to red giants to derive theoretical estimates of the photometric and photocentric stellar

The nature of p-modes and granulation in HD 49933 observed by CoRoT

Context. Recent observations of HD 49933 by the space-photometric mission CoRoT provide photometric evidence of solar type oscillations in a star other than our Sun. The first published reduction,

The underlying physical meaning of the νmax νc relation

Asteroseismology of stars that exhibit solar-like oscillations are enjoying a growing interest with the wealth of observational results obtained with the CoRoT and Kepler missions. In this framework,