Starspots: A Key to the Stellar Dynamo

Berdyugina, S. V.

doi:10.12942/lrsp-2005-8

Cited by 578 publications

(592 citation statements)

References 189 publications

(181 reference statements)

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“…However, no such distributions are present in D01 and D05, with the high fs around 180 • in D08 becoming much lower once the effects of irradiation and gravity darkening have been removed. Such 'active longitudes' are observed in single stars such as LQ Hya, AB Dor and EK Dra (Berdyugina 2005) as well as in RS CVn binaries (e.g. Rodonò et al 2000).…”

Section: Longitude Covermentioning

confidence: 93%

“…The 'flipflop' cycle occurs when the active longitude with the highest level of activity (i.e. the most spotted) switches to the opposite longitude, with cycles taking years to decades to occur (see Berdyugina 2005 for a summary). The disappearance of spot C in D04, as compared to D05, may imply the switching of dominant longitudes between observations of AE Aqr.…”

Section: Evolution Of High-latitude Spotsmentioning

confidence: 99%

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Roche tomography of cataclysmic variables – VII. The long-term magnetic activity of AE Aqr

Hill

Watson²,

Steeghs

et al. 2016

Mon. Not. R. Astron. Soc.

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We present a long-term study of the secondary star in the cataclysmic variable AE Aqr, using Roche tomography to indirectly image starspots on the stellar surface spanning 8 years of observations. The 7 maps show an abundance of spot features at both high and low latitudes. We find that all maps have at least one large high-latitude spot region, and we discuss its complex evolution between maps, as well as its compatibility with current dynamo theories. Furthermore, we see the apparent growth in fractional spot coverage, f s , around 45 • latitude over the duration of observations, with a persistently high f s near latitudes of 20 • . These bands of spots may form as part of a magnetic activity cycle, with magnetic flux tubes emerging at different latitudes, similar to the 'butterfly' diagram for the Sun. We discuss the nature of flux tube emergence in close binaries, as well as the activity of AE Aqr in the context of other stars.

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Section: Longitude Covermentioning

confidence: 93%

Section: Evolution Of High-latitude Spotsmentioning

confidence: 99%

Roche tomography of cataclysmic variables – VII. The long-term magnetic activity of AE Aqr

Hill

Watson²,

Steeghs

et al. 2016

Mon. Not. R. Astron. Soc.

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“…Such observations (reviewed in Berdyugina 2005) show that there is oftentimes a preferred longitude for starspots. Faster rotators tend to have large polar spots which contributes to a strong polar cap, while in general, in very active stars, the spot distribution tends to be more uniform across all latitudes.…”

Section: Starspots Polar Caps and Stellar Butterfly Diagramsmentioning

confidence: 99%

The Solar-Stellar Connection

Brun¹,

García²,

Houdek³

et al. 2017

Space Sciences Series of ISSI

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We discuss how recent advances in observations, theory and numerical simulations have allowed the stellar community to progress in its understanding of stellar convection, rotation and magnetism and to assess the degree to which the Sun and other stars share similar dynamical properties. Ensemble asteroseismology has become a reality with the advent of large time domain studies, especially from space missions. This new capability has provided improved constraints on stellar rotation and activity, over and above that obtained via traditional techniques such as spectropolarimetry or CaII H&K observations. New data and surveys covering large mass and age ranges have provided a wide parameter space to confront theories of stellar magnetism. These new empirical databases are complemented by theoretical advances and improved multi-D simulations of stellar dynamos. We trace these pathways through which a lucid and more detailed picture of magnetohydrodynamics of solar-like stars is beginning to emerge and discuss future prospects.

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“…The use of Doppler imaging techniques has revealed the surface structure (magnetic and otherwise) of a large number of stars (Berdyugina 2005, Strassmeier 2009). For the most part, these have been based on observations from a single site, with data obtained over several rotations to achieve full phase coverage.…”

Section: The Need For Continuous Spectroscopymentioning

confidence: 99%

Using SONG to probe rapid variability and evolution of starspots

et al. 2010

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Abstract. The Stellar Observations Network Group (SONG) is being developed as a network of 1-meter spectroscopic telescopes designed for and primarily dedicated to asteroseismology. It is patterned after the highly successful GONG project. The Danish prototype telescope will be installed in Tenerife in early 2011. Ultimately we hope to have as many as 8 identical nodes providing continuous high-resolution spectroscopic observations for targets anywhere in the sky. The primary scientific goals of SONG are asteroseismology and the search for Earth-mass exoplanets. The spectroscopic requirements for these programs push the limits of current technology, but the resulting spectrograph design will enable many secondary science programs with less stringent requirements. Doppler imaging of starspots can be accomplished using continuous observations over several stellar rotations using identical instrumentation at each node. It should be possible to observe the evolution of starspot morphology in real-time, for example. We discuss the design and status of the SONG project in general, and we describe how SONG could be used to probe short timescale changes in stellar surface structure.

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Starspots: A Key to the Stellar Dynamo

Cited by 578 publications

References 189 publications

Roche tomography of cataclysmic variables – VII. The long-term magnetic activity of AE Aqr

Roche tomography of cataclysmic variables – VII. The long-term magnetic activity of AE Aqr

The Solar-Stellar Connection

Using SONG to probe rapid variability and evolution of starspots

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