OBSERVATIONS OF A SERIES OF FLARES AND ASSOCIATED JET-LIKE ERUPTIONS DRIVEN BY THE EMERGENCE OF TWISTED MAGNETIC FIELDS

Journal Article · Wed Jan 20 00:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/817/1/39· OSTI ID:22521673

Lim, Eun-Kyung; Yurchyshyn, Vasyl; Kim, Sujin; Cho, Kyung-Suk; Kumar, Pankaj; Kim, Yeon-Han ^[1]; Park, Sung-Hong ^[2]; Chae, Jongchul; Yang, Heesu; Cho, Kyuhyoun; Song, Donguk ^[3]

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1. Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)
2. Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS), National Observatory of Athens, Penteli 15236 (Greece)
3. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)

We studied temporal changes of morphological and magnetic properties of a succession of four confined flares followed by an eruptive flare using the high-resolution New Solar Telescope (NST) operating at the Big Bear Solar Observatory (BBSO) and Helioseismic and Magnetic Imager (HMI) magnetograms and Atmospheric Image Assembly (AIA) EUV images provided by the Solar Dynamics Observatory (SDO). From the NST/Hα and the SDO/AIA 304 Å observations we found that each flare developed a jet structure that evolved in a manner similar to evolution of the blowout jet: (1) an inverted-Y-shaped jet appeared and drifted away from its initial position; (2) jets formed a curtain-like structure that consisted of many fine threads accompanied by subsequent brightenings near the footpoints of the fine threads; and finally, (3) the jet showed a twisted structure visible near the flare maximum. Analysis of the HMI data showed that both the negative magnetic flux and the magnetic helicity have been gradually increasing in the positive-polarity region, indicating the continuous injection of magnetic twist before and during the series of flares. Based on these results, we suggest that the continuous emergence of twisted magnetic flux played an important role in producing successive flares and developing a series of blowout jets.

• OSTI ID: 22521673
• Journal Information: Astrophysical Journal, Vol. 817, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CHROMOSPHERE
ERUPTION
EXTREME ULTRAVIOLET RADIATION
HELICITY
IMAGES
JETS
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIC PROPERTIES
RESOLUTION
SOLAR FLARES
SUN
TELESCOPES