Observing Stellar Granulation (Keynote)
Abstract
Granulation-induced photospheric spectrum line asymmetries can be detected with high-resolution stellar spectrometers. Such stellar line asymmetries are well respresented by bisectors which show changing shapes for lines of different strengths. The solar near-twin α Cen A shows a bisector pattern very similar to that of the Sun. F- and K-type main-sequence stars have line asymmetries reminiscent of solar ones, but very different from those of F- and K-type giants. Stellar bisector patterns are presented from very high-resolution (λ/Δλ ≅ 200,000) observations made with the ESO double-pass coudé echelle spectrometer, and the observability of stellar bisectors also at moderate resolutions (≅ 100,000) is shown.
- Publication:
-
Small-Scale Dynamical Processes in Quiet Stellar Atmospheres
- Pub Date:
- 1984
- Bibcode:
- 1984ssdp.conf..414D