Resolving the effects of rotation in altair with long-baseline interferometry

@article{Peterson2005ResolvingTE,
  title={Resolving the effects of rotation in altair with long-baseline interferometry},
  author={Deane M. Peterson and Christian A. Hummel and Thomas A. Pauls and John Thomas Armstrong and James A. Benson and Charmaine Gilbreath and Robert B. Hindsley and Donald Hutter and Kenneth J. Johnston and David Mozurkewich},
  journal={The Astrophysical Journal},
  year={2005},
  volume={636},
  pages={1087-1097}
}
We report the successful fitting of a Roche model, with a surface temperature gradient following the von Zeipel gravity darkening law, to observations of Altair made with the Navy Prototype Optical Interferometer. We confirm the claim by Ohishi et al. that Altair displays an asymmetric intensity distribution due to rotation, the first such detection in an isolated star. Instrumental effects due to the high visible flux of this first magnitude star appear to be the limiting factor in the… Expand

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References

SHOWING 1-10 OF 35 REFERENCES
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
ASYMMETRIC SURFACE BRIGHTNESS DISTRIBUTION OF ALTAIR OBSERVED WITH THE NAVY PROTOTYPE OPTICAL INTERFEROMETER
An asymmetric surface brightness distribution of the rapidly rotating A7 IV-V star Altair has been measured by the Navy Prototype Optical Interferometer (NPOI). The observations were recordedExpand
Resolving the effects of rotation in early type stars
We review the theory of rotating stars, first developed 80 years ago. Predictions include a specific relation between shape and angular velocity and between surface location and effective temperatureExpand
Direct multi-wavelength limb-darkening measurements of three late-type giants with the Navy Prototype Optical Interferometer
We present direct measurements of the limb-darkened intensity proles of the late-type giant stars HR 5299, HR 7635, and HR 8621 obtained with the Navy Prototype Optical Interferometer (NPOI) at theExpand
Modelling rapid rotators for stellar interferometry
Optical long baseline interferometry is a powerful tool to study detailed stellar structures. In particular, rapid rotation induces interferometric signatures requiring a detailed modelling forExpand
Altair's inclination from line profile analysis
We present a detailed spectroscopic study of line broadening in the A7IV-V star Altair. In a wavelength region covering 690 A we reconstruct the overall broadening profile taking into account moreExpand
Navy Prototype Optical Interferometer Observations of the Double Stars Mizar A and Matar
We present a detailed analysis of two spectroscopic binaries based on new observations obtained with the Navy Prototype Optical Interferometer (NPOI). While the data calibration needs refinement,Expand
Effects of gravitational darkening on the determination of fundamental parameters in fast-rotating B-type stars
In this paper we develop a calculation code to account for the effects carried by fast rotation on the observed spectra of early-type stars. Stars are assumed to be in rigid rotation, and the grid ofExpand
A SEARCH FOR CHROMOSPHERIC EMISSION IN A-TYPE STARS USING THE GODDARD HIGH-RESOLUTION SPECTROGRAPH
We have used the Goddard High-Resolution Spectrograph (GHRS) on the Hubble Space Telescope (HST) to search for chromospheric emission in the ultraviolet C II 1335 A lines of eight A-type stars. TheExpand
The effects of inclination, gravity darkening and differential rotation on absorption profiles of fast rotators
Mechanisms influencing absorption line profiles of fast rotating stars can be sorted into two groups; (i) intrinsic variations sensitive to temperature and pressure, and (ii) global eects common toExpand
...
1
2
3
4
...