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HINODE Operation Plan (HOP)

accepted on

25-aug-2017


 HOP No.

 HOP title

HOP 0342

Small-scale activities of magnetic loops in the solar atmosphere

plan term

2017/08/26-2017/08/31

@ @

proposer

 name : Huang @  e-mail : huangzhenghua[at]gmail.com

contact person in HINODE team

 name : Savage @  e-mail : sabrina.savage[at]nasa.gov

 abstract of observational proposal
We aim to understand how magnetic loops evolve to produce small-scale reconnection events and their dynamics at different temperatures (i.e, from chromosphere to corona).

Small-scale activities of magnetic loops observed in the lower solar atmosphere, including Ellerman bombs, IRIS bombs and explosive events, are crucial as they might describe how magnetic energy is released in the lower solar atmosphere and heat the plasma therein. The proposed coordinated observations aim to understand how magnetic loops evolve to produce these small-scale reconnection events and their dynamics at different temperatures (i.e, from chromosphere to corona). We plan the joint observations with BBSO/NST, IRIS and Hinode. Our proposal to NST and IRIS has been already accepted and arranged in the interval of August 26-31. The plasma beta in and above the solar chromosphere is mostly less than 1, which suggests the plasmas therein are mostly frozen-in magnetic field lines. Magnetic loops, therefore, are one of the fundamental building blocks in the solar atmosphere. Magnetic loops in the chromosphere and transition region might include the fibril and cool loops (e.g. Chae et al. 2000; Huang et al. 2015, etc.). Some fascinate phenomena have been found to be associated with evolution of these loops. A historical one is Ellerman bombs (Ellerman 1917; Fang et al. 2006) that are identified by enhanced Ha wings together with normal line centre and are believed to be signatures of magnetic reconnection in the photosphere (e.g., Watanabe et al. 2007; Vissers et al. 2013; Rutten et al. 2013; Tian et al. 2016; etc.). A popular one is IRIS bombs firstly identify in IRIS spectral data (Peter et al. 2014; Tian et al. 2016; etc.) occurring while magnetic loops are emerging as serpentine (Peter et al. 2014). Transition region explosive events (Brueckner et al. 1983; Dere et al. 1989; Ning et al. 2004; Huang et al. 2014), which have been suggested to be signatures of magnetic reconnection (Dere et al. 1989; Innes et al. 1997), can also be found to closely associate with interaction between magnetic loops (e.g. Huang et al. 2015, 2017). These phenomena are crucial as they might describe how magnetic energy is released in the lower solar atmosphere and heat the plasma therein. Here, we propose a coordinated observing campaign using BBSO/NST, IRIS and Hinode to obtain magnetic field, spectral and imaging data, which covering observations from the solar photosphere to corona. With these data, we aim to understand how magnetic loops evolve to produce these small-scale reconnection events and their dynamics at different temperatures (i.e, from chromosphere to corona).

 request to SOT
17:00-18:30 UT
one SP full IQUV scans (normal map, FOV 160hx160h, 0.16h slit, 83 min scan) during the coordinated observation.

 request to XRT
17:00-23:00 UT
FOV completely covers the SOT/SP FOV 1hresolution, cadence 60 seconds or higher. G-band image is needed for alignment purpose, but the exposure is very low cadence.

 request to EIS
17:00-23:00 UT
Observing the same target region as SOT/SP. Repeating raster scan. Raster with 1h slit and 40 seconds exposure time. Both SW and LW lines are required. The spectral windows are the larger the better.

 other participating instruments
IRIS: has granted 18:00-23:00 UT from 26 to 29 in August; and 17:00-23:00 UT on 30/31 August.

BBSO/NST (BFI, FISS and VIS): Has granted August 26-31 for this observing proposal, and the good seeing at BBSO is 17:00-23:00 UT

 remarks
Targets:
The target would be any active region (ideally an emerging one) on the solar disk, which is abundant of magnetic loops.

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