Hans Bruntt | Aarhus University (original) (raw)

Hans Bruntt

Address: Aarhus, Midtjylland, Denmark

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Papers by Hans Bruntt

Research paper thumbnail of Stromgren Photometry of Open Clusters: NGC6134 and NGC3680

Master Thesis Institute of Physics and Astronomy Aarhus University, 1999

Research paper thumbnail of K Giant Stars Observed with WIRE: Lifetimes and Amplitudes

ABSTRACT Following the failure of the main experiment on board the Wide-Field Infrared Explorer s... more ABSTRACT Following the failure of the main experiment on board the Wide-Field Infrared Explorer satellite (WIRE), the on-board star camera was used as the first space-based asteroseismology experiment. From May 1999 through November 2006, well over 200 targets were observed for periods ranging up to 40+ days. The typical noise level (measured at a frequency of 10 mHz) of these observations was

Research paper thumbnail of New WIRE Detections of Oscillations in K Giants

Bulletin of the American Astronomical Society, Dec 1, 2004

WIRE observations of K giants (e.g., alpha Boo, Retter et al. 2004) have revealed the presence of... more WIRE observations of K giants (e.g., alpha Boo, Retter et al. 2004) have revealed the presence of low-level variability in some K giants which is at least quasi-periodic, and which is suggestive of p-mode oscillations. In 2004 (Preston, Bruntt and Buzasi, Cool Stars 13), we presented new WIRE oscillation data for five K giants, some of which were strongly periodic.

Research paper thumbnail of Str�mgren photometry of the open clusters NGC 6134 and NGC 3680

Astron Astrophys Suppl Series, 1999

ABSTRACT

Research paper thumbnail of TEMPLOGG for determining stellar parameters of MONS targets

Research paper thumbnail of Oscillation mode identifications and models for the delta Scuti star FG Virginis

Astronomy and Astrophysics, Apr 18, 1998

Research paper thumbnail of Detection of Granulation in Procyon

Bulletin of the American Astronomical Society, Dec 1, 2004

ABSTRACT The WIRE satellite has observed the F-type star Procyon for two periods during 1999 and ... more ABSTRACT The WIRE satellite has observed the F-type star Procyon for two periods during 1999 and 2000. The two data sets consist of time series of 10 days length with a cadence of 0.5 seconds and a duty cycle of 15 than the Sun and thus [the photometric signal arising from] granulation is expected to have higher amplitude. We have used the two WIRE data sets to put an upper limit on the granulation and find this to be close to a factor of two times the amplitude seen in the Sun. This limit is lower than the factor [of] five proposed by observations with the Canadian MOST mission (Matthews et al. 2004). Due to the rather low duty cycle in the WIRE data set we are not able to confirm the oscillations seen in Procyon from radial velocity measurements (Martic et al. 2004).

Research paper thumbnail of VizieR Online Data Catalog: Stromgren Photometry in NGC 3680 and NGC 6134 (Bruntt+, 1999)

Vizier Online Data Catalog, Jun 1, 1999

Research paper thumbnail of Determining the Age of the Kepler Open Cluster NGC 6819 with a New Triple System and Other Eclipsing Binary Stars

The Astronomical Journal, 2016

Research paper thumbnail of Modelling of the fast rotating d Scuti star Altair

Research paper thumbnail of Accurate Fundamental Stellar Parameters

Proceedings of the International Astronomical Union, 2009

We combine results from interferometry, asteroseismology and spectroscopic analyses to determine ... more We combine results from interferometry, asteroseismology and spectroscopic analyses to determine accurate fundamental parameters (mass, radius and effective temperature) of 10 bright solar-type stars covering the H-R diagram from spectral type F5 to K1. Using “direct” techniques that are only weakly model-dependent we determine the mass, radius and effective temperature. We demonstrate that model-dependent or “indirect” methods can be reliably used even for relatively faint single stars for which direct methods are not applicable. This is important for the characterization of the targets of the CoRoT and Kepler space missions.

Research paper thumbnail of ASTROPHYSICS SX Phœnicis Stars in the Core of 47 Tucanae

Research paper thumbnail of A Semi-Automatic Method for Abundance Analysis. Two Case Studies: the Giant Star ksi Hydrae and the delta Scuti Stars in NGC 6134

Proceedings of the International Astronomical Union

Research paper thumbnail of Stromgren Photometry in NGC 3680 and NGC 6134 (Bruntt+, 1999)

Research paper thumbnail of Studies of Stellar Clusters: Steps towards Asteroseismology and a Search for Giant Planets

Research paper thumbnail of A star catalog for the open cluster NGC 6791 (Stetson+, 2003)

Research paper thumbnail of Tools and Methods for Abundance Analysis

Proceedings of The International Astronomical Union, 2003

Research paper thumbnail of Oscillations and magnetic fields in the G8 star EK Eridani

Research paper thumbnail of Testing convection in stellar models using detached eclipsing binaries

Proceedings of the International Astronomical Union, 2006

The fundamental properties of detached eclipsing binary stars can be measured very accurately, wh... more The fundamental properties of detached eclipsing binary stars can be measured very accurately, which could make them important objects for constraining the treatment of convection in theoretical stellar models. However, only four or five pieces of information can be found for the average system, which is not enough. We discuss studies of more interesting and useful objects: eclipsing binaries in clusters and eclipsing binaries with pulsating components.

Research paper thumbnail of Velocity curves of SW CMa and HW CMa (Torres+, 2012)

Research paper thumbnail of Stromgren Photometry of Open Clusters: NGC6134 and NGC3680

Master Thesis Institute of Physics and Astronomy Aarhus University, 1999

Research paper thumbnail of K Giant Stars Observed with WIRE: Lifetimes and Amplitudes

ABSTRACT Following the failure of the main experiment on board the Wide-Field Infrared Explorer s... more ABSTRACT Following the failure of the main experiment on board the Wide-Field Infrared Explorer satellite (WIRE), the on-board star camera was used as the first space-based asteroseismology experiment. From May 1999 through November 2006, well over 200 targets were observed for periods ranging up to 40+ days. The typical noise level (measured at a frequency of 10 mHz) of these observations was

Research paper thumbnail of New WIRE Detections of Oscillations in K Giants

Bulletin of the American Astronomical Society, Dec 1, 2004

WIRE observations of K giants (e.g., alpha Boo, Retter et al. 2004) have revealed the presence of... more WIRE observations of K giants (e.g., alpha Boo, Retter et al. 2004) have revealed the presence of low-level variability in some K giants which is at least quasi-periodic, and which is suggestive of p-mode oscillations. In 2004 (Preston, Bruntt and Buzasi, Cool Stars 13), we presented new WIRE oscillation data for five K giants, some of which were strongly periodic.

Research paper thumbnail of Str�mgren photometry of the open clusters NGC 6134 and NGC 3680

Astron Astrophys Suppl Series, 1999

ABSTRACT

Research paper thumbnail of TEMPLOGG for determining stellar parameters of MONS targets

Research paper thumbnail of Oscillation mode identifications and models for the delta Scuti star FG Virginis

Astronomy and Astrophysics, Apr 18, 1998

Research paper thumbnail of Detection of Granulation in Procyon

Bulletin of the American Astronomical Society, Dec 1, 2004

ABSTRACT The WIRE satellite has observed the F-type star Procyon for two periods during 1999 and ... more ABSTRACT The WIRE satellite has observed the F-type star Procyon for two periods during 1999 and 2000. The two data sets consist of time series of 10 days length with a cadence of 0.5 seconds and a duty cycle of 15 than the Sun and thus [the photometric signal arising from] granulation is expected to have higher amplitude. We have used the two WIRE data sets to put an upper limit on the granulation and find this to be close to a factor of two times the amplitude seen in the Sun. This limit is lower than the factor [of] five proposed by observations with the Canadian MOST mission (Matthews et al. 2004). Due to the rather low duty cycle in the WIRE data set we are not able to confirm the oscillations seen in Procyon from radial velocity measurements (Martic et al. 2004).

Research paper thumbnail of VizieR Online Data Catalog: Stromgren Photometry in NGC 3680 and NGC 6134 (Bruntt+, 1999)

Vizier Online Data Catalog, Jun 1, 1999

Research paper thumbnail of Determining the Age of the Kepler Open Cluster NGC 6819 with a New Triple System and Other Eclipsing Binary Stars

The Astronomical Journal, 2016

Research paper thumbnail of Modelling of the fast rotating d Scuti star Altair

Research paper thumbnail of Accurate Fundamental Stellar Parameters

Proceedings of the International Astronomical Union, 2009

We combine results from interferometry, asteroseismology and spectroscopic analyses to determine ... more We combine results from interferometry, asteroseismology and spectroscopic analyses to determine accurate fundamental parameters (mass, radius and effective temperature) of 10 bright solar-type stars covering the H-R diagram from spectral type F5 to K1. Using “direct” techniques that are only weakly model-dependent we determine the mass, radius and effective temperature. We demonstrate that model-dependent or “indirect” methods can be reliably used even for relatively faint single stars for which direct methods are not applicable. This is important for the characterization of the targets of the CoRoT and Kepler space missions.

Research paper thumbnail of ASTROPHYSICS SX Phœnicis Stars in the Core of 47 Tucanae

Research paper thumbnail of A Semi-Automatic Method for Abundance Analysis. Two Case Studies: the Giant Star ksi Hydrae and the delta Scuti Stars in NGC 6134

Proceedings of the International Astronomical Union

Research paper thumbnail of Stromgren Photometry in NGC 3680 and NGC 6134 (Bruntt+, 1999)

Research paper thumbnail of Studies of Stellar Clusters: Steps towards Asteroseismology and a Search for Giant Planets

Research paper thumbnail of A star catalog for the open cluster NGC 6791 (Stetson+, 2003)

Research paper thumbnail of Tools and Methods for Abundance Analysis

Proceedings of The International Astronomical Union, 2003

Research paper thumbnail of Oscillations and magnetic fields in the G8 star EK Eridani

Research paper thumbnail of Testing convection in stellar models using detached eclipsing binaries

Proceedings of the International Astronomical Union, 2006

The fundamental properties of detached eclipsing binary stars can be measured very accurately, wh... more The fundamental properties of detached eclipsing binary stars can be measured very accurately, which could make them important objects for constraining the treatment of convection in theoretical stellar models. However, only four or five pieces of information can be found for the average system, which is not enough. We discuss studies of more interesting and useful objects: eclipsing binaries in clusters and eclipsing binaries with pulsating components.

Research paper thumbnail of Velocity curves of SW CMa and HW CMa (Torres+, 2012)

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