Far Ultraviolet Continuum Emission: Applying this Diagnostic to the Chromospheres of Solar-Mass Stars

Details Far Ultraviolet Continuum Emission: Applying this Diagnostic to the Chromospheres of Solar-Mass Stars Far Ultraviolet Continuum Emission: Applying this Diagnostic to the Chromospheres of Solar-Mass Stars

2011-09-26

arxiv.org/abs/1109.5653v1

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

21 pages, 5 figures, to appear in ApJ

Scientific paper

The far ultraviolet (FUV) continuum flux is recognized as a very sensitive diag- nostic of the temperature structure of the Sun's lower chromosphere. Until now analysis of the available stellar FUV data has shown that solar-type stars must also have chromospheres, but quantitative analyses of stellar FUV continua require far higher quality spectra and comparison with new non-LTE chromosphere models. We present accurate far ultraviolet (FUV, 1150-1500^{\circ}) continuum flux measurements for solar-mass stars, made feasible by the high throughput and very low detector background of the Cosmic Origins Spectrograph (COS) on the Hubbble Space Telescope. We show that the continuum flux can be measured above the detector background even for the faintest star in our sample. We find a clear trend of increasing continuum brightness temperature at all FUV wavelengths with decreasing rotational period, which provides an important measure of magnetic heating rates in stellar chromospheres. Comparison with semiempirical solar flux models shows that the most rapidly rotating solar-mass stars have FUV continuum brightness temperatures similar to the brightest faculae seen on the Sun. The thermal structure of the brightest solar faculae therefore provides a first-order estimate of the thermal structure and heating rate for the most rapidly rotating solar-mass stars in our sample.

Affiliated with

Also associated with

No associations

Rating

Far Ultraviolet Continuum Emission: Applying this Diagnostic to the Chromospheres of Solar-Mass Stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Far Ultraviolet Continuum Emission: Applying this Diagnostic to the Chromospheres of Solar-Mass Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Far Ultraviolet Continuum Emission: Applying this Diagnostic to the Chromospheres of Solar-Mass Stars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-689968