TY - JOUR
T1 - Constraining the Physical Properties of Stellar Coronal Mass Ejections with Coronal Dimming
T2 - Application to Far-ultraviolet Data of ϵ Eridani
AU - Loyd, R. O.Parke
AU - Mason, James Paul
AU - Jin, Meng
AU - Shkolnik, Evgenya L.
AU - France, Kevin
AU - Youngblood, Allison
AU - Villadsen, Jackie
AU - Schneider, Christian
AU - Schneider, Adam C.
AU - Llama, Joe
AU - Ramiaramanantsoa, Tahina
AU - Richey-Yowell, Tyler
N1 - Funding Information:
R.O.P.L. conducted this research under program HST-AR-15803. Support for program HST-AR-15803 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Associations of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 526555. These observations are associated with program(s) 13650, 14909, and 15365. CHIANTI is a collaborative project involving George Mason University, the University of Michigan (USA), University of Cambridge (UK) and NASA Goddard Space Flight Center (USA). The solar CME catalog used in this work is generated and maintained at the CDAW Data Center by NASA and The Catholic University of America in cooperation with the Naval Research Laboratory. SOHO is a project of international cooperation between ESA and NASA.
Funding Information:
R.O.P.L. conducted this research under program HST-AR-15803. Support for program HST-AR-15803 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Associations of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. This research is based on observations made with the NASA/ESA Hubble Space Telescope obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 526555. These observations are associated with program(s) 13650, 14909, and 15365. CHIANTI is a collaborative project involving George Mason University, the University of Michigan (USA), University of Cambridge (UK) and NASA Goddard Space Flight Center (USA). The solar CME catalog used in this work is generated and maintained at the CDAW Data Center by NASA and The Catholic University of America in cooperation with the Naval Research Laboratory. SOHO is a project of international cooperation between ESA and NASA.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/9/1
Y1 - 2022/9/1
N2 - Coronal mass ejections (CMEs) are a prominent contributor to solar system space weather and might have impacted the Sun’s early angular momentum evolution. A signal diagnostic of CMEs on the Sun is coronal dimming: a drop in coronal emission, tied to the mass of the CME, that is the direct result of removing emitting plasma from the corona. We present the results of a coronal dimming analysis of Fe xii 1349 Å and Fe xxi 1354 Å emission from ϵ Eridani (ϵ Eri), a young K2 dwarf, with archival far-ultraviolet observations by the Hubble Space Telescope’s Cosmic Origins Spectrograph. Following a flare in 2015 February, ϵ Eri’s Fe xxi emission declined by 81 ± 5%. Although enticing, a scant 3.8 minutes of preflare observations allows for the possibility that the Fe xxi decline was the decay of an earlier, unseen flare. Dimming nondetections following each of three prominent flares constrain the possible mass of ejected Fe xii-emitting (1 MK) plasma to less than a few × 1015 g. This implies that CMEs ejecting this much or more 1 MK plasma occur less than a few times per day on ϵ Eri. On the Sun, 1015 g CMEs occur once every few days. For ϵ Eri, the mass-loss rate due to CME-ejected 1 MK plasma could be < 0.6 M ̇ ⊙ , well below the star’s estimated 30 M ̇ ⊙ mass-loss rate (wind + CMEs). The order-of-magnitude formalism we developed for these mass estimates can be broadly applied to coronal dimming observations of any star.
AB - Coronal mass ejections (CMEs) are a prominent contributor to solar system space weather and might have impacted the Sun’s early angular momentum evolution. A signal diagnostic of CMEs on the Sun is coronal dimming: a drop in coronal emission, tied to the mass of the CME, that is the direct result of removing emitting plasma from the corona. We present the results of a coronal dimming analysis of Fe xii 1349 Å and Fe xxi 1354 Å emission from ϵ Eridani (ϵ Eri), a young K2 dwarf, with archival far-ultraviolet observations by the Hubble Space Telescope’s Cosmic Origins Spectrograph. Following a flare in 2015 February, ϵ Eri’s Fe xxi emission declined by 81 ± 5%. Although enticing, a scant 3.8 minutes of preflare observations allows for the possibility that the Fe xxi decline was the decay of an earlier, unseen flare. Dimming nondetections following each of three prominent flares constrain the possible mass of ejected Fe xii-emitting (1 MK) plasma to less than a few × 1015 g. This implies that CMEs ejecting this much or more 1 MK plasma occur less than a few times per day on ϵ Eri. On the Sun, 1015 g CMEs occur once every few days. For ϵ Eri, the mass-loss rate due to CME-ejected 1 MK plasma could be < 0.6 M ̇ ⊙ , well below the star’s estimated 30 M ̇ ⊙ mass-loss rate (wind + CMEs). The order-of-magnitude formalism we developed for these mass estimates can be broadly applied to coronal dimming observations of any star.
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U2 - 10.3847/1538-4357/ac80c1
DO - 10.3847/1538-4357/ac80c1
M3 - Article
AN - SCOPUS:85143116299
SN - 0004-637X
VL - 936
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 170
ER -