Evolution of stellar winds from the Sun to red giants

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Waves, Mhd, Sun: Photosphere, Sun: Chromosphere, Sun: Corona, Solar Wind, Stars: Chromospheres, Stars: Coronae, Stars: Magnetic Fields, Stars: Mass Loss, Stars: Late-Type

Scientific paper

By performing global 1D MHD simulations, we investigate the heating and acceleration of solar and stellar winds in open magnetic field regions. Our simulation covers from photosphere to 20-60 stellar radii, and takes into account radiative cooling and thermal conduction. We do not adopt ad hoc heating function; heating is automatically calculated from the solutions of Riemann problem at the cell boundaries. In the solar wind case we impose transverse photospheric motions with velocity ~1 km/s and period between 20 seconds and 30 minutes, which generate outgoing Alfvén waves. We have found that the dissipation of Alfvén waves through compressive wave generation by decay instability is quite effective owing to the density stratification, which leads to the sufficient heating and acceleration of the coronal plasma. Next, we study the evolution of stellar winds from main sequence to red giant phases. When the stellar radius becomes ~10 times of the Sun, the steady hot corona with temperature 106 K, suddenly disappears. Instead, many hot and warm (105 - 106 K) bubbles are formed in cool (T < 2 × 104 K) chromospheric winds because of the thermal instability of the radiative cooling function; the red giant wind is not a steady stream but structured outflow.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Evolution of stellar winds from the Sun to red giants 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 Evolution of stellar winds from the Sun to red giants, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of stellar winds from the Sun to red giants will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-978574

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.