The effects of opacity in the transition region of YZ CMi

Details The effects of opacity in the transition region of YZ CMi The effects of opacity in the transition region of YZ CMi

Nov 1999

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999a%26a...351l..23m&link_type=abstract

Astronomy and Astrophysics, v.351, p.L23-L26 (1999)

Astronomy and Astrophysics

Astrophysics

8

Atomic Data, Stars: Activity, Stars: Atmospheres, Stars: Individual: Yz Cmi, Stars: Late-Type, Ultraviolet: Stars

Scientific paper

It has generally been assumed that the emission from the upper atmosphere of late-type stars is optically thin. In the present paper we use the Si IV and C IV resonance lines to investigate this assumption for the active dMe star YZ CMi. The significant deviations of the line ratios from their optically thin values, demonstrate that opacity can be quite important particularly in the case of stellar flares. These deviations are combined with a method of escape probabilities to derive optical depths of approximately unity for the lines under consideration. We demonstrate that, if the electron density in the atmosphere is known, opacity can provide important information on the linear dimensions of the scattering layer. Using this technique, we have estimated path lengths of a few kilometers for one of the flares under consideration. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.

Affiliated with

Also associated with

No associations

Rating

The effects of opacity in the transition region of YZ CMi 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 The effects of opacity in the transition region of YZ CMi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The effects of opacity in the transition region of YZ CMi will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1283003