Stellar and molecular radii of a Mira star: First observations with the Keck Interferometer grism

Joshua A Eisner, J. R. Graham, R. L. Akeson, E. R. Ligon, M. M. Colavita, G. Basri, K. Summers, S. Ragland, A. Booth

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Using a new grism at the Keck Interferometer, we obtained spectrally dispersed (R ∼ 230) interferometric measurements of the Mira star R Vir. These data show that the measured radius of the emission varies substantially from 2.0 to 2.4 μm. Simple models can reproduce these wavelength-dependent variations using extended molecular layers, which absorb stellar radiation and reemit it at longer wavelengths. Because we observe spectral regions with and without substantial molecular opacity, we determine the stellar photospheric radius, uncontaminated by molecular emission. We infer that most of the molecular opacity arises at approximately twice the radius of the stellar photosphere.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume654
Issue number1 II
DOIs
StatePublished - Jan 1 2007
Externally publishedYes

Fingerprint

interferometer
interferometers
opacity
wavelength
stars
radii
stellar radiation
photosphere
wavelengths
radiation

Keywords

  • Circumstellar matter
  • Instrumentation: interferometers
  • Stars: AGB and post-AGB
  • Stars: individual (R Virginis)
  • Techniques: interferometric
  • Techniques: spectroscopic

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Eisner, J. A., Graham, J. R., Akeson, R. L., Ligon, E. R., Colavita, M. M., Basri, G., ... Booth, A. (2007). Stellar and molecular radii of a Mira star: First observations with the Keck Interferometer grism. Astrophysical Journal, 654(1 II). https://doi.org/10.1086/510717

Stellar and molecular radii of a Mira star : First observations with the Keck Interferometer grism. / Eisner, Joshua A; Graham, J. R.; Akeson, R. L.; Ligon, E. R.; Colavita, M. M.; Basri, G.; Summers, K.; Ragland, S.; Booth, A.

In: Astrophysical Journal, Vol. 654, No. 1 II, 01.01.2007.

Research output: Contribution to journalArticle

Eisner, JA, Graham, JR, Akeson, RL, Ligon, ER, Colavita, MM, Basri, G, Summers, K, Ragland, S & Booth, A 2007, 'Stellar and molecular radii of a Mira star: First observations with the Keck Interferometer grism', Astrophysical Journal, vol. 654, no. 1 II. https://doi.org/10.1086/510717
Eisner, Joshua A ; Graham, J. R. ; Akeson, R. L. ; Ligon, E. R. ; Colavita, M. M. ; Basri, G. ; Summers, K. ; Ragland, S. ; Booth, A. / Stellar and molecular radii of a Mira star : First observations with the Keck Interferometer grism. In: Astrophysical Journal. 2007 ; Vol. 654, No. 1 II.
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AU - Akeson, R. L.

AU - Ligon, E. R.

AU - Colavita, M. M.

AU - Basri, G.

AU - Summers, K.

AU - Ragland, S.

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