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 J. T. Armstrong and J. A. Benson and G. Charmaine Gilbreath and Robert B. Hindsley and Donald J. Hutter and Kenneth J. Johnston and David Mozurkewich and Henrique R. Schmitt},
  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… 

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References

SHOWING 1-10 OF 33 REFERENCES

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 temperature

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 the

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 more

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 for

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,

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 of

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 to

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. The

New insights into nonradiative heating in late A star chromospheres

Using new and archival spectra from the Goddard High Resolution Spectrograph, we have searched for evidence of chromospheric and transition region emission in six stars of mid to late A spectral

Multichannel Optical Aperture Synthesis Imaging of zeta1 URSAE Majoris with the Navy Prototype Optical Interferometer

We have used the Navy Prototype Optical Interferometer (NPOI) to obtain the first multichannel optical aperture synthesis images of a star. We observed the spectroscopic binary ~ 1 Ursae Majoris at 6