A search for chromospheric emission in A-type stars using the Goddard High-Resolution Spectrograph

Theodore Simon; Wayne B. Landsman; Ronald L. Gilliland

doi:10.1086/174242

A search for chromospheric emission in A-type stars using the Goddard High-Resolution Spectrograph

Theodore Simon, Wayne B. Landsman, Ronald L. Gilliland

Astronomy & Astrophysics

Research output: Contribution to journal › Article › peer-review

15 Scopus citations

Abstract

We have used the Goddard High-Resolution Spectrograph on the Hubble Space Telescope to search for chromospheric emission in the ultraviolet C II 1335 Å lines of eight A-type stars. The B-V colors of these stars range from 0.12 to 0.22. We have detected emission in the spectrum of the A7 V star Altair, but in no other star. We present tentative evidence that the emission from Altair is blueshifted by ∼60 km s^-1 or more with respect to the photospheric spectrum of this star. We interpret this as expansion and suggest that the base of the A star winds that we have proposed in earlier work may lie within the chromosphere. Together with IUE spectra, our observations indicate that in ordinary main-sequence stars the onset of convection zones capable of supporting detectable chromospheres occurs in the close vicinity of B-V = 0.22.

Original language	English (US)
Pages (from-to)	319-323
Number of pages	5
Journal	Astrophysical Journal
Volume	428
Issue number	1
DOIs	https://doi.org/10.1086/174242
State	Published - Jun 10 1994

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1086/174242

Fingerprint Dive into the research topics of 'A search for chromospheric emission in A-type stars using the Goddard High-Resolution Spectrograph'. Together they form a unique fingerprint.

Cite this

@article{687caf276f60480f9dcc931b4600f4c4,

title = "A search for chromospheric emission in A-type stars using the Goddard High-Resolution Spectrograph",

abstract = "We have used the Goddard High-Resolution Spectrograph on the Hubble Space Telescope to search for chromospheric emission in the ultraviolet C II 1335 {\AA} lines of eight A-type stars. The B-V colors of these stars range from 0.12 to 0.22. We have detected emission in the spectrum of the A7 V star Altair, but in no other star. We present tentative evidence that the emission from Altair is blueshifted by ∼60 km s-1 or more with respect to the photospheric spectrum of this star. We interpret this as expansion and suggest that the base of the A star winds that we have proposed in earlier work may lie within the chromosphere. Together with IUE spectra, our observations indicate that in ordinary main-sequence stars the onset of convection zones capable of supporting detectable chromospheres occurs in the close vicinity of B-V = 0.22.",

author = "Theodore Simon and Landsman, {Wayne B.} and Gilliland, {Ronald L.}",

year = "1994",

month = jun,

day = "10",

doi = "10.1086/174242",

language = "English (US)",

volume = "428",

pages = "319--323",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "1",

}

TY - JOUR

T1 - A search for chromospheric emission in A-type stars using the Goddard High-Resolution Spectrograph

AU - Simon, Theodore

AU - Landsman, Wayne B.

AU - Gilliland, Ronald L.

PY - 1994/6/10

Y1 - 1994/6/10

N2 - We have used the Goddard High-Resolution Spectrograph on the Hubble Space Telescope to search for chromospheric emission in the ultraviolet C II 1335 Å lines of eight A-type stars. The B-V colors of these stars range from 0.12 to 0.22. We have detected emission in the spectrum of the A7 V star Altair, but in no other star. We present tentative evidence that the emission from Altair is blueshifted by ∼60 km s-1 or more with respect to the photospheric spectrum of this star. We interpret this as expansion and suggest that the base of the A star winds that we have proposed in earlier work may lie within the chromosphere. Together with IUE spectra, our observations indicate that in ordinary main-sequence stars the onset of convection zones capable of supporting detectable chromospheres occurs in the close vicinity of B-V = 0.22.

AB - We have used the Goddard High-Resolution Spectrograph on the Hubble Space Telescope to search for chromospheric emission in the ultraviolet C II 1335 Å lines of eight A-type stars. The B-V colors of these stars range from 0.12 to 0.22. We have detected emission in the spectrum of the A7 V star Altair, but in no other star. We present tentative evidence that the emission from Altair is blueshifted by ∼60 km s-1 or more with respect to the photospheric spectrum of this star. We interpret this as expansion and suggest that the base of the A star winds that we have proposed in earlier work may lie within the chromosphere. Together with IUE spectra, our observations indicate that in ordinary main-sequence stars the onset of convection zones capable of supporting detectable chromospheres occurs in the close vicinity of B-V = 0.22.

UR - http://www.scopus.com/inward/record.url?scp=12044250940&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=12044250940&partnerID=8YFLogxK

U2 - 10.1086/174242

DO - 10.1086/174242

M3 - Article

AN - SCOPUS:12044250940

VL - 428

SP - 319

EP - 323

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

ER -

A search for chromospheric emission in A-type stars using the Goddard High-Resolution Spectrograph

Abstract

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Cite this