# Altair: The Brightest δ Scuti Star

@article{Buzasi2004AltairTB,
title={Altair: The Brightest $\delta$ Scuti Star},
author={Derek L. Buzasi and Hans Bruntt and Timothy R. Bedding and A. J. Retter and Hans Kjeldsen and Heather L. Preston and William J. Mandeville and Joseph H. Catanzarite and Tim Conrow and Russ R. Laher},
journal={The Astrophysical Journal},
year={2004},
volume={619},
pages={1072-1076}
}
We present an analysis of observations of the bright star Altair (α Aql) obtained using the star camera on the Wide Field Infrared Explorer (WIRE) satellite. Although Altair lies within the δ Scuti instability strip, previous observations have not revealed the presence of oscillations. However, the WIRE observations show Altair to be a low-amplitude (Δm < 1 parts per thousand [ppt]) δ Scuti star with at least seven modes present.

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#### References

SHOWING 1-10 OF 22 REFERENCES
Oscillations in Arcturus from WIRE photometry
• Physics
• 2003
Observations of the red giant Arcturus (Alpha Boo) obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a baseline of 19 successive days in 2000 July-August areExpand
delta Scuti and related stars: Analysis of the R00 Catalogue
• Physics
• 2001
We present a comprehensive analysis of the properties of the pulsating δ Scuti and related variables based mainly on the content of the recently published catalogue by Rodriguez et al. ([CITE],Expand
DELTA SCUTI AND RELATED STARS.
An extensive review is given of the current status of our knowledge of the stars in the lower instability strip. Current problems are emphasized. Particular attention is given to the following areas:Expand
CHARM: A Catalog of High Angular Resolution Measurements
• Physics
• 2002
The Catalog of High Angular Resolution Measurements (CHARM) includes most of the measurements obtained by the techniques of lunar occultations and long-baseline interferometry at visual and infraredExpand
Rotation of stars in NGC 6134 ⋆ A comparison of δ Scuti stars and non-variable stars
• Physics
• 2002
We present results of spectroscopic observations of selected stars in the southern open cluster NGC 6134. We have determined the rotational velocities of the six known Scuti stars in NGC 6134 as wellExpand
Altair’s Oblateness and Rotation Velocity from Long-Baseline Interferometry
We present infrared interferometric angular size measurements for the A7IV-V star Altair that indicate a noncircular projected disk brightness distribution. Given the known rapid rotation of thisExpand
Spectroscopic survey of $\delta$ Scuti stars - I. Rotation velocities and effective temperatures
• Physics
• 1997
Projected rotational velocities and eective temperatures for 68 Sct stars as well as 41 non{variable stars of similar spectral type and luminosity are presented here. The rotational velocities haveExpand
HR 6434 and the factors limiting pulsational amplitudes of del SCT stars.
The frequency structure of HR 6434 is examined and compared with the observed limiting magnitudes of other delta Scuti stars in order to discuss various hypotheses for the wide range of observedExpand
Automated spectroscopic abundances of A and F-type stars using echelle spectrographs - II. Abundances of 140 A-F stars from ELODIE and CORALIE
• Physics
• 2003
Using the method presented in Erspamer & North (2002, hereafter Paper I), detailed abundances of 140 stars are presented. The uncertainties characteristic of this method are presented and discussed.Expand
Period--luminosity--color relations and pulsation modes of pulsating variable stars
• Physics
• 1975
The periods of delta Scuti, RR Lyrae, dwarf Cepheid, and W Virginis variables have been investigated for their dependence on luminosity, color, mass, and pulsation modes. A maximum-likelihood method,Expand