THE AGES OF A-STARS. I. INTERFEROMETRIC OBSERVATIONS AND AGE ESTIMATES FOR STARS IN THE URSA MAJOR MOVING GROUP

@article{Jones2015THEAO,
title={THE AGES OF A-STARS. I. INTERFEROMETRIC OBSERVATIONS AND AGE ESTIMATES FOR STARS IN THE URSA MAJOR MOVING GROUP},
author={Jeremy Jones and R. J. White and Tabetha S. Boyajian and Gail H. Schaefer and Ellyn K. Baines and Michael J. Ireland and Jennifer L. Patience and Theo A. ten Brummelaar and Harold A. Mcalister and Stephen T. Ridgway and Judit Sturmann and Laszlo Sturmann and Nils H. Turner and Christopher D. Farrington and P. J. Goldfinger},
journal={The Astrophysical Journal},
year={2015},
volume={813}
}
• Published 23 August 2015
• Physics
• The Astrophysical Journal
We have observed and spatially resolved a set of seven A-type stars in the nearby Ursa Major moving group with the Classic, CLIMB, and PAVO beam combiners on the Center for High Angular Resolution Astronomy Array. At least four of these stars have large rotational velocities ( v sin i ≳ ?> 170 km s − 1 ?> ) and are expected to be oblate. These interferometric measurements, the stars’ observed photometric energy distributions, and v sin i ?> values are used to computationally construct model…
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References

SHOWING 1-10 OF 63 REFERENCES

STELLAR DIAMETERS AND TEMPERATURES. I. MAIN-SEQUENCE A, F, AND G STARS

• Physics
• 2012
We have executed a survey of nearby, main-sequence A-, F-, and G-type stars with the CHARA Array, successfully measuring the angular diameters of forty-four stars with an average precision of ∼1.5%.

Gravity darkening in rotating stars

• Physics
• 2011
Context. Interpretation of interferometric observations of rapidly rotating stars requires a good model of their surface effective temperature. Until now, laws of the form Teff ∝ g βff have been

Rotational velocities of A-type stars - IV. Evolution of rotational velocities

• Physics, Geology
• 2012
Context. In previous works of this series, we have shown that late B- and early A-type stars have genuine bimodal distributions of rotational velocities and that late A-type stars lack slow rotators.

Rotational velocities of A-type stars. III. Velocity distributions

• Physics
• 2007
Aims. A sample of $v\sin i$ of B9 to F2-type main sequence single stars has been built from highly homogeneous ${v\sin i}$ parameters determined for a large sample cleansed of objects presenting the

Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I.

• Physics
• 2003
We have embarked on a project, under the aegis of the Nearby Stars (NStars)/Space Interferometry Mission Preparatory Science Program, to obtain spectra, spectral types, and, where feasible, basic

Extrasolar planets and brown dwarfs around A–F type stars - IV. A candidate brown dwarf around the A9V pulsating star HD 180777

• Physics, Geology
• 2006
We present here the detection of a brown dwarf orbiting the A9V star HD 180777. The radial velocity measurements, obtained with the ELODIE echelle spectrograph at the Haute-Provence Observatory, show

COLDER AND HOTTER: INTERFEROMETRIC IMAGING OF β CASSIOPEIAE AND α LEONIS

• Physics
• 2011
Near-infrared interferometers have recently imaged a number of rapidly rotating A-type stars, finding levels of gravity darkening inconsistent with theoretical expectations. Here, we present new

First Results from the CHARA Array. VII. Long-Baseline Interferometric Measurements of Vega Consistent with a Pole-On, Rapidly Rotating Star

• Physics
• 2006
We have obtained high-precision interferometric measurements of Vega with the CHARA Array and FLUOR beam combiner in the K′ band at projected baselines between 103 and 273 m. The measured visibility

Normal A0−A1 stars with low rotational velocities - I. Abundance determination and classification

• Physics
• 2014
Context. The study of rotational velocity distributions for normal stars requires an accurate spectral characterization of the objects in order to avoid polluting the results with undetected binary

High-Precision Near-Infrared Photometry of a Large Sample of Bright Stars Visible from the Northern Hemisphere

• Physics, Geology
• 2003
We present the results of 8 yr of infrared photometric monitoring of a large sample of stars visible from Teide Observatory (Tenerife, Canary Islands). The final archive is made up of 10,949