SIMBAD references

2006A&A...460..751S - Astronomy and Astrophysics, volume 460, 751-758 (2006/12-4)

First Doppler images of the very young K2-dwarf PW Andromedae = HD 1405.


Abstract (from CDS):

We present the first Doppler images of the single pre-main-sequence star PW And. Its position in the HR-diagram suggests it to be in the rapid-braking phase just prior to arrival on the ZAMS. Images are obtained from seven individual spectral lines as well as from 5-nm wide chunks of spectrum that invert a total of 58 line profiles simultaneously. Cool spots with temperature differences with respect to the stellar photosphere of up to 1200K are detected. Spot occurrence is mostly within an equatorial band up to ±40° of the stellar equator and thus contradicts magnetic-flux tube emergence models based on young K-star properties that predict an emerging latitude in two distinct bands of +45-55°. This confirms previous suggestions that current magnetic-flux tube models predict emergence latitudes too low for G-dwarfs and too high for K-dwarfs, which may be caused by the fact that the G-dwarf models heavily rely on comparisons with the Sun. We also redetermine the absolute parameters of PW And in the light of a missing Hipparcos parallax and revise its age to be more near 20Myr, in agreement with its logarithmic lithium abundance of 2.87±0.05. A precise rotational period of 1.76159±0.00006d was found from our photometric data in 2004.

Abstract Copyright:

Journal keyword(s): stars: activity - stars: starspots - stars: imaging - stars: individual: PW Andromedae - stars: pre-main sequence - stars: fundamental parameters

Simbad objects: 6

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