Rotational Modulation, Shear, And Cyclic Activity In HII 2927
Abstract
We present a 15 yr compilation of V-band differential photometry for the Pleiades K4 dwarf HII 2927 (V378 Tau). HII 2927 has a rotational period (P_rot) of 0.26 d and displays significant rotational modulation due to non-uniform surface brightness or "starspots". With the long timeline of data available we can explore many aspects of the star's photometric variability, with the goal of including them in a larger study of magnetic activity in single cool dwarfs. Preliminary work yields a cycle period (P_cyc) of 14.5 +/- 1.9 yrs. We also present preliminary work on the rotational shear for this star (ΔP_rot/<P_rot>). Measurements of P_cyc and rotational shear contribute to our understanding of the magnetic dynamo at the source of stellar activity. We compare our P_cyc and ΔP_rot/<P_rot> estimates with those of other stars, including our measurements of fellow Pleaid HII 1883 (V660 Tau).
- Publication:
-
American Astronomical Society Meeting Abstracts #220
- Pub Date:
- May 2012
- Bibcode:
- 2012AAS...22032806M