Magnetic activity of the solar-like star HD 140538
Abstract
The periods of rotation and activity cycles are among the most important properties of the magnetic dynamo thought to be operating in late-type, main-sequence stars. In this paper, we present a SMWO-index time series composed from different data sources for the solar-like star HD 140538 and derive a period of 3.88 ± 0.02 yr for its activity cycle. Furthermore, we analyse the high-cadence, seasonal SMWO data taken with the TIGRE telescope and find a rotational period of 20.71 ± 0.32 days. In addition, we estimate the stellar age of HD 140538 as 3.7 Gyrs via a matching evolutionary track. This is slightly older than the ages obtained from gyrochronology based on the above rotation period, as well as the activity-age relation. These results, together with its stellar parameters that are very similar to a younger Sun, make HD 140538 a relevant case study for our understanding of solar activity and its evolution with time.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 2019
- DOI:
- 10.1051/0004-6361/201935654
- arXiv:
- arXiv:1907.04575
- Bibcode:
- 2019A&A...628A.107M
- Keywords:
-
- stars: atmospheres;
- stars: activity;
- stars: chromospheres;
- stars: late-type;
- stars: individual: HD 140538;
- stars: rotation;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 7 pages, 6 figures, accepted for publication in A&