Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
The First Direct Measurement to the Diameter of a Population II Star; Observationally Determined Fundamental Properties of µ Cas A with the CHARA Array
Authors:
Boyajian, Tabetha S.; McAlister, H. A.
Affiliation:
AA(Georgia State Univ.), AB(Georgia State Univ.)
Publication:
American Astronomical Society, AAS Meeting #211, #57.15; Bulletin of the American Astronomical Society, Vol. 39, p.832
Publication Date:
12/2007
Origin:
AAS
Bibliographic Code:
2007AAS...211.5715B

Abstract

Possessing the longest optical interferometric baselines in the world, the CHARA Array is uniquely suited to measure the diameters of stars, which are generally unresolved by other optical interferometers.

Using the longest baselines of the CHARA Array, we have measured the angular diameter of the subdwarf µ Cas A, the first such determination for a halo population star. We compare this result to new diameters for the K0 V stars, σ Dra and HD 10780, and find that the metal-poor star, µ Cas A, has an effective temperature (Teff=5353±26; K), radius (R=0.779±0.004 Rsun), and absolute luminosity (L=0.4475±0.0097 Lsun) comparable to the other two stars with later spectral types. We show that these results provide a key to understanding the fundamental relationships for stars with low metallicity.

In addition, we present the current results to our survey of nearby, main sequence, A, F, and G-type stars with the CHARA Array in order to determine highly accurate angular diameters. The accuracy and target sample range are aimed at refining, as well as expanding, the existing diameter measurements, which are used in the calibration of numerous less direct methods based on photometric parameters to predict stellar diameters and effective temperatures of stars. Currently, we have measured diameters to thirty-two new objects. Research at the CHARA Array is supported by the College of Arts and Sciences at Georgia State University and by the National Science

Foundation through NSF Grant AST 0606958.

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints