The Detection of Multimodal Oscillations on α Ursae Majoris

Buzasi, Derek L.; Catanzarite, J.; Laher, Russ R.; Conrow, T.; Shupe, D. L.; Gautier, T. N.; Kreidl, T. J.; Everett, David L.

doi:10.1086/312573

Cited by 104 publications

(106 citation statements)

References 26 publications

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“…Tentative p-mode oscillations have been identified on UMa A by Buzasi et al (2000) using the star camera on the failed Wide Field Infrared Explorer satellite. UMa A is the primary star, of spectral type K0 III, in a visual binary system.…”

Section: Uma Amentioning

confidence: 99%

“…We also only looked at the radial modes, since the nonradial mode frequencies are not regularly spaced (see the discussion in . Following a trial run, we decided to decrease the mode-matching parameter NREJECT to 1, since there are only 10 modes identified by Buzasi et al (2000) to begin with.…”

Section: Uma Amentioning

confidence: 99%

“…We present results of tests on low-l solar data, and we describe successful applications of the mode-matching method to the recently observed p-mode oscillation modes on Cen A by and on UMa by Buzasi et al (2000).…”

Section: Introductionmentioning

confidence: 99%

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Matching Stellar Models to Oscillation Data

Guenther

Brown

2004

ApJ

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We describe a method to match stellar models to a set of low-l p-mode oscillation frequencies. The method provides a quality of fit measure similar to that obtained from a 2 fit. With a sufficiently dense grid of stellar models, the method can determine the best-fitting model to the oscillation data as constrained solely by the oscillation data. That is to say, the method can be used to constrain the mass, age, composition, surface temperature, and luminosity of a star from the oscillation data. We evaluate the method on solar data and apply the method to the recently observed oscillation data for Cen and UMa.

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Section: Uma Amentioning

confidence: 99%

Section: Uma Amentioning

confidence: 99%

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Matching Stellar Models to Oscillation Data

Guenther

Brown

2004

ApJ

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“…Bedding & Kjeldsen 2007, and references thereafter), which was made possible by the development of a new generation of spectrographs with high enough precision to detect the small amplitudes (typically of a few tens of cm/s) of stochastically-driven oscillations, in stars other than the Sun. Since then, observations of pulsating stars from space have also become possible, first with the tiny 5 cm star tracker mounted on the NASA WIRE satellite (Buzasi et al 2000), followed by the 15 cm Canadian-led satellite MOST (Walker et al 2003) and the 27 cm French-led satellite CoRoT (Michel et al 2008). These satellites and high-precision, ground-based, campaigns conducted in the past few years (e.g.…”

Section: Introductionmentioning

confidence: 99%

Probing tiny convective cores with the acoustic modes of lowest degree

Cunha

Brandão

2011

A&A

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Solar-like oscillations are expected to be excited in stars of up to about 1.6 solar masses. Most of these stars will have convective cores during their main-sequence evolution. At the edges of these convective cores, there is a rapid variation in the sound speed, which influences the frequencies of acoustic oscillations. In this paper we build on earlier work to investigate the impact that these rapid structural variations have on different p-mode frequency combinations, involving modes of low degree. In particular, we adopt a different expression to describe the sound speed variation at the edge of the core, which we show more closely reproduces the profiles derived from the equilibrium models. We analyse the impact of this change on the frequency perturbation derived for radial modes. Moreover, we consider three different small frequency separations involving modes of degree l = 0, 1, 2, 3, l = 0, 1, and l = 0, 2, and show that they are all significantly affected by the sharp sound speed variation at the edge of the core. In particular, we confirm that the frequency derivative of the diagnostic tool that combines modes of degree up to 3 can potentially be used to infer the amplitude of the relative sound speed variation directly at the edge of the core. We show that at high frequencies the other two diagnostic tools can be up to a few μHz smaller than what would be expected in the absence of the rapid structural variation at the edge of the core. Also, we show that the absolute values of their frequency derivatives are significantly increased, in a manner that strongly depends on stellar age.

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“…Also, Edmonds & Gilliland (1996) found variations in K giants in the globular cluster 47 Tuc which were apparently consistent with solar-like pulsations. Recently, based on observations with the WIRE star tracker Buzasi et al (2000) claimed detection of solar-like oscillations in a Ursa Majoris A, a giant of spectral type KO III, with an estimated mass, from membership of a binary system, of around 5M 0 . analyzed the evolution and oscillation frequencies of this star.…”

Section: Subgiants and Red Giantsmentioning

confidence: 99%

Recent Progress in Asteroseismology

Christensen‐Dalsgaard

2001

Symp. - Int. Astron. Union

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Abstract. Asteroseismology, the study of stellar interiors on the basis of observations of multi-mode stellar oscillations, extends over a large part of the Hertzsprung-Russell diagram. The recently discovered EC14026 stars promise information about the properties of stars on the horizontal branch. Solar-like oscillations excited stochastically by convection have been tentatively identified in a few cases. Promising examples are giant stars, where the expected amplitudes may make ground-based observations of the oscillations relatively straightforward. Major advances can be expected from the upcoming asteroseismic space projects under development or study, including the Eddington mission adopted by ESA as a 'reserve mission' in the recent round of selections.

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The Detection of Multimodal Oscillations on α Ursae Majoris

Cited by 104 publications

References 26 publications

Matching Stellar Models to Oscillation Data

Matching Stellar Models to Oscillation Data

Probing tiny convective cores with the acoustic modes of lowest degree

Recent Progress in Asteroseismology

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