Astronomy and Astrophysics – Astrophysics
Scientific paper
Jan 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005ap.....48...20a&link_type=abstract
Astrophysics, Volume 48, Issue 1, pp.20-31
Astronomy and Astrophysics
Astrophysics
3
Stars, Spots, Activity Cycle, Stars - Spots - Activity Cycle
Scientific paper
The first results are reported from a search for activity cycles in stars similar to the sun based on modelling their spotting with an algorithm developed at the Crimean Astrophysical Observatory. Of the more than thirty program stars, 10 manifested a cyclical variation in their central latitudes and total starspot area. The observed cycles have durations of 4-15 years, i.e., analogous to the 11 year Schwabe sunspot cycle. Most of the stars have a rough analog of the solar butterfly pattern, with a reduction in the average latitude of the spots as their area increases. A flip-flop effect during the epoch of the maximum average latitude is noted in a number of these objects (e.g., the analog LQ Hya of the young sun or the RS CVn-type variable V711 Tau), as well as a reduction in the photometric rotation period of a star as the spots drift toward the equator, an analog of the differential rotation effect in the sun. Unlike in the sun, the observed spot formation cycles do not correlate uniquely with other indicators of activity— chromospheric emission in the CaII HK lines (Be Cet, EK Dra, Dx Leo), H line emission (LQ Hya, VY Ari, EV Lac), or cyclical flare activity (EV Lac). In V833 Tau, BY Dra, EK Dra, and VY Ari short Schwabe cycles coexist with long cycles that are analogous to the Gleissberg solar cycle, in which the spotted area can approach half the entire area of the star.
No associations
LandOfFree
Spots, activity cycles, and differential rotation on cool stars 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 Spots, activity cycles, and differential rotation on cool stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spots, activity cycles, and differential rotation on cool stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-895080