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Subhajeet Karmakar, Jeewan Chandra Pandey, Sachindra Naik, Igor S. Savanov & Ashish Raj

Magnetic activities on active solar-type stars

(Volume 88 - Année 2019 — Actes de colloques — 2nd Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - October 2018 - Brussels, Belgium)
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Mots-clés : étoiles, activité, champ magnétique imagerie

Abstract

Indian Institute of Astrophysics, II Block Koramangala, Bangalore 560034, India

We present results obtained from the studies of magnetic activities on four solar-type stars (F-type star KIC 6791060, K-type star LO Peg, and two M-type planet-hosting stars K2–33 and EPIC 211901114) by using optical observations from several ground- and space-based telescopes. In this study, we investigate magnetic activities such as spot-topographic evolution and flaring events in these stars. We compare the results obtained from this study with that of the Sun. In the surface temperature maps, one active longitude has been detected in KIC 6791060, whereas in each of the other three cases two active longitudes are seen. The spottedness was found to vary in the range of 0.07–0.44%, 9–26%, 3.6–4.2%, and 4.5–5.3% for KIC 6791060, LO Peg, K2–33, and EPIC 211901114, respectively. Several flaring events have been identified in each star. An increasing trend in flaring frequency per stellar rotation has been found in the stars with change in spectral type from F to M. These findings indicate the increase in magnetic activities with the spectral type of stars. This can be explained due to increasing the ratio of the thickness of the convection zone to the radiation zone from F-type star to the M-type stars.

Keywords : stars, activity, magnetic field, flare, imaging, starspots

To cite this article

Subhajeet Karmakar, Jeewan Chandra Pandey, Sachindra Naik, Igor S. Savanov & Ashish Raj, «Magnetic activities on active solar-type stars», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 88 - Année 2019, Actes de colloques, 2nd Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop - October 2018 - Brussels, Belgium, 182 - 189 URL : https://popups.uliege.be/0037-9565/index.php?id=8822.

About: Subhajeet Karmakar

Physical Research Laboratory, Navrangapura, Ahmedabad 380009, India and Aryabhatta Research Institute of observational Sciences, Nainital 263002, India, subhajeet@prl.res.in

About: Jeewan Chandra Pandey

Aryabhatta Research Institute of observational Sciences, Nainital 263002, India

About: Sachindra Naik

Physical Research Laboratory, Navrangapura, Ahmedabad 380009, India

About: Igor S. Savanov

Institute of Astronomy, Russian Academy of Sciences, ul. Pyatniskaya 48, Moscow 119017, Russia

About: Ashish Raj

Indian Institute of Astrophysics, II Block Koramangala, Bangalore 560034, India