Further images of α Persei G dwarfs

Details Further images of α Persei G dwarfs Further images of α Persei G dwarfs

Sep 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001mnras.326.1057b&link_type=abstract

Monthly Notices of the Royal Astronomical Society, Volume 326, Issue 3, pp. 1057-1066.

Astronomy and Astrophysics

Astronomy

24

Line: Profiles, Stars: Activity, Stars: Imaging, Stars: Late-Type, Stars: Spots

Scientific paper

We present two images of intermediate and low axial inclination G dwarfs (AP 149 and AP 193) in the young open cluster α Persei, and compare these with previous images of intermediate and high axial inclination objects in this cluster. All stars show starspots at high latitudes, with one star exhibiting a strong polar spot. Although low-latitude features are found on all stars to some degree, the detection of spots on AP 193 is marginal. The apparent difference in starspot morphology from one object to the next is probably the result of a stellar magnetic cycle, although the exact effect on the starspot distribution throughout a cycle is unknown. Polar spots are found in many Doppler images of rapidly rotating cool stars. In the past, their existence has been called into question, and it has been suggested that they could be the manifestations of NLTE (e.g. chromospheric filling in of line profiles) effects rather than real photospheric features. We assume the polar spots to be real photospheric features, and conclude that the flat-bottomed nature of the profile shape can be attributed to photospheric polar spots. The degree of truncation of the profile depends not only on spot size and strength, but also on the effective foreshortening of the polar region, a function of axial inclination. Hα is in emission on AP 149 which shows a double peak at most phases. The time-series of the profile shows an s-wave pattern as the position of these peaks changes throughout the rotation cycle. We attribute this to coronal clouds located above the stellar surface in synchronous orbit. A maximum-entropy tomogram is derived revealing four distinct emission regions located near and above the corotation radius.

Affiliated with

Also associated with

No associations

Rating

Further images of α Persei G dwarfs 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 Further images of α Persei G dwarfs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Further images of α Persei G dwarfs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1155266