Excess Hα emission in chromospherically active binaries.

Details Excess Hα emission in chromospherically active binaries. Excess Hα emission in chromospherically active binaries.

Feb 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995a%26a...294..165m&link_type=abstract

Astronomy and Astrophysics 294, 165-176 (1995)

Astronomy and Astrophysics

Astrophysics

80

Stars: Activity, Stars: Binaries: Close, Stars: Chromospheres, Stars: Late-Type, Stars: Rotation

Scientific paper

We study the behaviour of the excess Hα emission in a sample of 51 chromospherically active binary systems (RS CVn and BY Dra classes), of different activity levels. This sample include the 27 stars analysed by Fernandez-Figueroa et al. (1994) and the new observations of 24 systems described by Montes et al. (1994b). By using the spectral subtraction technique (subtraction of a synthesized stellar spectrum constructed from reference stars of similar spectral type and luminosity class) we obtain the active-chromosphere contribution to the Hα line in these 51 systems. We have determined the excess Hα emission equivalent widths and converted it to surface fluxes. The Hα emissions arising from each component star were obtained when it was possible to deblend both contributions. The comparison of the excess Hα emission, obtained with the spectral subtraction technique, with other Hα activity indices allows us to conclude that this is the preferable activity indicator for binaries. The behaviour of the excess Hα emission as a function of the rotation has been analyzed. A slight decline toward longer rotational periods, P_rot_, and larger Rossby numbers, R_0_, is present in agreement with previous results using others activity indicators. We have compared the derived excess Hα emission fluxes with those obtained in the Ca II K and Hɛ lines finding that a good correlation exits between these three chromospheric activity indicators. The Hα losses seem to be more important than Ca II K losses for cooler stars, in fact all the system with Hα emission above the continuum are cooler than 5000K. Correlations with other activity indicators, (C IV in the transition region, and X-rays in the corona) indicate that the exponents of the power-law relations increase with the formation temperature of the spectral features.

Affiliated with

Also associated with

No associations

Rating

Excess Hα emission in chromospherically active binaries. 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 Excess Hα emission in chromospherically active binaries., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Excess Hα emission in chromospherically active binaries. will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1629096