Multiwavelength Campaign Observations of a Young Solar-type Star, EK Draconis. I. Discovery of Prominence Eruptions Associated with Superflares

Kosuke Namekata; Vladimir S. Airapetian; Pascal Petit; Hiroyuki Maehara; Kai Ikuta; Shun Inoue; Yuta Notsu; Rishi R. Paudel; Zaven Arzoumanian; Antoaneta A. Avramova-Boncheva; Keith Gendreau; Sandra V. Jeffers; Stephen Marsden; Julien Morin; Coralie Neiner; Aline A. Vidotto; Kazunari Shibata

doi:10.3847/1538-4357/ad0b7c

The Astrophysical Journal (Jan 2024)

Multiwavelength Campaign Observations of a Young Solar-type Star, EK Draconis. I. Discovery of Prominence Eruptions Associated with Superflares

Kosuke Namekata,
Vladimir S. Airapetian,
Pascal Petit,
Hiroyuki Maehara,
Kai Ikuta,
Shun Inoue,
Yuta Notsu,
Rishi R. Paudel,
Zaven Arzoumanian,
Antoaneta A. Avramova-Boncheva,
Keith Gendreau,
Sandra V. Jeffers,
Stephen Marsden,
Julien Morin,
Coralie Neiner,
Aline A. Vidotto,
Kazunari Shibata

Affiliations

Kosuke Namekata: ORCiD; ALMA Project, National Astronomical Observatory of Japan , NINS, Osawa, Mitaka, Tokyo, 181-8588, Japan ; [email protected], [email protected]
Vladimir S. Airapetian: ORCiD; Sellers Exoplanetary Environments Collaboration, NASA Goddard Space Flight Center , Greenbelt, MD, USA; Department of Physics, American University , Washington, DC, USA
Pascal Petit: ORCiD; Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse , CNRS, CNES, 14 avenue Édouard Belin, F-31400 Toulouse, France
Hiroyuki Maehara: ORCiD; Okayama Branch Office, Subaru Telescope, National Astronomical Observatory of Japan , NINS, Kamogata, Asakuchi, Okayama 719-0232, Japan
Kai Ikuta: ORCiD; Department of Multidisciplinary Sciences, The University of Tokyo , 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
Shun Inoue: ORCiD; Department of Physics, Kyoto University , Sakyo, Kyoto 606-8502, Japan
Yuta Notsu: ORCiD; Laboratory for Atmospheric and Space Physics, University of Colorado Boulder , 3665 Discovery Drive, Boulder, CO 80303, USA; National Solar Observatory , 3665 Discovery Drive, Boulder, CO 80303, USA
Rishi R. Paudel: ORCiD; NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771, USA; University of Maryland , Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
Zaven Arzoumanian: NASA Goddard Space Flight Center , Greenbelt, MD, USA
Antoaneta A. Avramova-Boncheva: ORCiD; Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences , 72 Tsarigradsko Chaussee Boulevard, 1784 Sofia, Bulgaria
Keith Gendreau: ORCiD; NASA Goddard Space Flight Center , Greenbelt, MD, USA
Sandra V. Jeffers: ORCiD; Max Planck Institute for Solar System Research , Justus-von-Liebig-weg 3, D-37077 Göttingen, Germany
Stephen Marsden: ORCiD; Centre for Astrophysics, University of Southern Queensland , Toowoomba, Queensland 4350, Australia
Julien Morin: ORCiD; LUPM, Université de Montpellier , CNRS, Place Eugène Bataillon, F-34095 Montpellier, France
Coralie Neiner: ORCiD; LESIA, Paris Observatory, PSL University , CNRS, Sorbonne University, Université Paris Cité, 5 place Jules Janssen, F-92195 Meudon, France
Aline A. Vidotto: ORCiD; Leiden Observatory, Leiden University , PO Box 9513, 2300 RA Leiden, The Netherlands
Kazunari Shibata: ORCiD; Kwasan Observatory, Kyoto University , Yamashina, Kyoto 607-8471, Japan; School of Science and Engineering, Doshisha University , Kyotanabe, Kyoto 610-0321, Japan

DOI: https://doi.org/10.3847/1538-4357/ad0b7c
Journal volume & issue: Vol. 961, no. 1
p. 23

Abstract

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Young solar-type stars frequently produce superflares, serving as a unique window into the young Sun-Earth environments. Large solar flares are closely linked to coronal mass ejections (CMEs) associated with filament/prominence eruptions, but observational evidence for stellar superflares remains scarce. Here, we present a 12-day, multiwavelength campaign observation of young solar-type star EK Draconis (G1.5V, 50–120 Myr age) utilizing the Transiting Exoplanet Survey Satellite, the Neutron star Interior Composition ExploreR, and the Seimei telescope. The star has previously exhibited blueshifted H α absorptions as evidence for a filament eruption associated with a superflare. Our simultaneous optical and X-ray observations identified three superflares of 1.5 × 10 ^33 –1.2 × 10 ^34 erg. We report the first discovery of two prominence eruptions on a solar-type star, observed as blueshifted H α emissions at speeds of 690 and 430 km s ^−1 and masses of 1.1 × 10 ^19 and 3.2 × 10 ^17 g, respectively. The faster, massive event shows a candidate of post-flare X-ray dimming with the amplitude of up to ∼10%. Several observational aspects consistently point to the occurrence of a fast CME associated with this event. The comparative analysis of the estimated length scales of flare loops, prominences, possible dimming region, and starspots provides the overall picture of the eruptive phenomena. Furthermore, the energy partition of the observed superflares in the optical and X-ray bands is consistent with flares from the Sun, M-dwarfs, and close binaries, yielding the unified empirical relations. These discoveries provide profound implications of the impact of these eruptive events on early Venus, Earth, and Mars and young exoplanets.

Published in The Astrophysical Journal

ISSN: 1538-4357 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy: Astrophysics
Website: https://iopscience.iop.org/journal/0004-637X

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