English
Related papers

Related papers: A search for solar-like oscillations and granulati…

200 papers

We have been using a new method to search for solar-like oscillations that involves measuring temperature changes via their effect on the equivalent widths of the Balmer hydrogen lines. We observed alpha Cen A over six nights in 1995 with…

Astrophysics · Physics 2007-05-23 Timothy R. Bedding , Hans Kjeldsen , S. Frandsen , T. H. Dall

We have observed evidence for $p$-mode oscillations in the G0 IV star etaBoo (V = 2.68). This represents the first clear evidence of solar-like oscillations in a star other than the Sun. We used a new technique which measures fluctuations…

Astrophysics · Physics 2009-10-22 Hans Kjeldsen , Timothy R. Bedding , Michael Viskum , Soeren Frandsen

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

Solar and Stellar Astrophysics · Physics 2015-06-15 C. Karoff , T. L. Campante , J. Ballot , T. Kallinger , M. Gruberbauer , R. A. Garcia , D. A. Caldwell , J. L. Christiansen , K. Kinemuchi

We have made a clear detection of p-mode oscillations in the nearest solar-like G2V star $\alpha$ Cen A with the CORALIE spectrograph on the 1.2-m Swiss telescope at the ESO La Silla Observatory. We report the 5 nights of observation on…

Astrophysics · Physics 2016-08-30 Francois Bouchy , Fabien Carrier

Solar-like oscillations are excited by near-surface convection and are being observed in growing numbers of stars using ground and space-based telescopes. We have previously suggested an empirical scaling relation to predict their…

Solar and Stellar Astrophysics · Physics 2015-05-27 Hans Kjeldsen , Timothy R. Bedding

We have made velocity observations of the star alpha Cen B from two sites, allowing us to identify 37 oscillation modes with l=0-3. Fitting to these modes gives the large and small frequency separations as a function of frequency. The mode…

Excitation of solar-like oscillations is attributed to turbulent convection and takes place at the upper-most part of the outer convective zones. Amplitudes of these oscillations depend on the efficiency of the excitation processes as well…

Astrophysics · Physics 2009-05-04 R. Samadi , K. Belkacem , M. -J. Goupil , F. Kupka , M. -A. Dupret

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…

Solar and Stellar Astrophysics · Physics 2014-10-15 T. Kallinger , J. De Ridder , S. Hekker , S. Mathur , B. Mosser , M. Gruberbauer , R. A. Garcia , C. Karoff , J. Ballot

We report evidence for the granulation signal in the star Procyon A, based on two photometric time series from the star tracker on the WIRE satellite. The power spectra show evidence of excess power around 1 milliHz, consistent with the…

Astrophysics · Physics 2009-11-11 H. Bruntt , H. Kjeldsen , D. L. Buzasi , T. R. Bedding

An interesting asteroseismic target is the G9.5 IV solar-like star beta Aql. This is an ideal target for asteroseismic investigations, because precise astrometric measurements are available from Hipparcos that greatly help in constraining…

Solar and Stellar Astrophysics · Physics 2015-05-30 E. Corsaro , F. Grundahl , S. Leccia , A. Bonanno , H. Kjeldsen , L. Paternò

Asteroseismology provides a unique tool for studying stellar interiors. Recently p modes have been detected on the bright solar-like star alpha Cen A thanks to high-precision radial-velocity measurements. However a better characterisation…

Astrophysics · Physics 2009-11-13 M. Bazot , F. Bouchy , H. Kjeldsen , S. Charpinet , M. Laymand , S. Vauclair

We recently reported strong evidence for solar-like oscillations in the G0 IV star eta Boo (Kjeldsen et al. 1995, AJ 109, 1313). We measured small temperature fluctuations produced by oscillations through their effect on the equivalent…

Astrophysics · Physics 2016-08-30 T. R. Bedding , H. Kjeldsen

We report the firm discovery of solar-like oscillations in a giant star. We monitored the star xi Hya (G7III) continuously during one month with the CORALIE spectrograph attached to the 1.2m Swiss Euler telescope. The 433 high-precision…

Despite numerous attempts and many hours of telescope time, there has so far been no confirmed detection of solar-like oscillations in any star except the Sun. We review recent efforts, with particular emphasis on the technique of…

Astrophysics · Physics 2007-05-23 Timothy R. Bedding , Hans Kjeldsen

We report on the first asteroseismic analysis of solar-type stars observed by Kepler. Observations of three G-type stars, made at one-minute cadence during the first 33.5d of science operations, reveal high signal-to-noise solar-like…

As a part of an on-going program to explore the signature of p-modes in solar-like stars by means of high-resolution absorption lines pectroscopy, we have studied four stars (alfaCMi, etaCas A, zetaHer A and betaVir). We present here new…

Astrophysics · Physics 2009-11-10 M. Martic , J. -C. Lebrun , T. Appourchaux , S. G. Korzennik

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 these changes provide diagnostics on the…

Solar and Stellar Astrophysics · Physics 2017-02-08 René Kiefer , Ariane Schad , Guy Davies , Markus Roth

Kjeldsen et al. (1995, AJ 109, 1313; astro-ph/9411016) have developed a new technique for measuring stellar oscillations and claimed a detection in the G subgiant eta Boo. The technique involves monitoring temperature fluctuations in a star…

Astrophysics · Physics 2015-06-24 T. R. Bedding , H. Kjeldsen , J. Reetz , B. Barbuy

We have measured solar-like oscillations in red giants using time-series photometry from the first 34 days of science operations of the Kepler Mission. The light curves, obtained with 30-minute sampling, reveal clear oscillations in a large…

To expand the range in the colour-magnitude diagram where asteroseismology can be applied, we organized a photometry campaign to find evidence for solar-like oscillations in giant stars in the globular cluster M4. The aim was to detect the…

‹ Prev 1 2 3 10 Next ›