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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0191

Observations of the Chromosphere Coordinated with BBSO/NST

plan term


@ @


 name : Chae, Tsuneta @  e-mail : jcchae[at]snu.ac.kr

contact person in HINODE team

 name : Kubo @  e-mail : masahito.kubo[at]nao.ac.jp

 abstract of observational proposal
We propose a series of Hinode and BBSO coordinated observations to investigate physical processes in the solar chromosphere. The importance of this poorly understood layer of the solar atmosphere is increasing in the solar research.

For the study of chromospheric features, Chae and his collaborators have developed the Fast Imaging Solar Spectrograph (FISS) on the New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO). From the early observations of a quiet region using this instrument, they obtained solid evidence that strong shocks of three-minute period are not only dominating the dynamics of the upper chromosphere of the intranetwork quiet region, but also are responsible for the heating of the chromosphere and corona there. This gave them a strong motivation to investigate shock phenomenon and other processes in the soalr chromosphere in detail.  On the other hand, Tsuneta and his collaborators not only have  produced a number of significant scientific results using the Hinode, but also are now preparing for a challenging sounding rocket experiment: the Chromospheric Lyman-alpha SpectroPolarimeter (CLASP) that aims to measure magnetic field of chromospheric features using the Hanle effect in Lyman alpha. If successfully carried out, this instrument will open a new era of directly measuring magnetic field in the chromospheric level.    

We focus on shocks and magnetic reconnection events occurring in the chromosphere in various contexts. It is very likely that shocks are very common in the chromosphere and have different natures (acoustic, slow or fast), mostly depending on the magnetic environment. Chromospheric reconnection events may often occur in various scales, with some being associated with cancelling magnetic features. The ultimate goal of our study is to reveal their physical natures and estimate how each of these processes is important in the heating of the chromospheres and corona. In addition, of our specific interest is whether reconnection events drive waves that develop into shocks.      

Our approach is to combine 1) magnetic and velocity data of the photosphere taken by Hinode/SOT, and 2) spectral data and imaging data of the chromospheres taken by FISS/NST and Hinode/SOT 3) spectral data of the corona taken by Hinode/EIS.  
We propose to operate two-hour observing run for each target each day.  The targets include 1) a near-disk-center quiet region, 2) a near-limb quiet region 3) a plage region 4) a sunspot 5) a pore. The specific choice of the target is to be made by the observer at time as close to the observing day as possible.

 request to SOT
total data volume=2253 Mbits
1) SP:  single side mode, 9 fast maps of  82h x 82h FOV (256x256x112x1x4 format)  at a cadence of 15 min. (data volume=77 Mbits x 9 = 693Mbits)
2) Ca II H BFI: 111h x 111h FOV,  2x2 binning (0.108h pix,1024x1024 format), at a cadence of 16 s. (data volume= 540 Mbits)
3) NFI NaI D -160 mA I and V:  164hx164h FOV, 2x2 binning (0.16h pix) at a cadence of 64 s (data volume=1020 Mbits)

 request to XRT

 request to EIS
Raster type:

1) raster type to obtain a width of about 60h at the start and end of the observing run

2) sit at the center of FOV & stare (for fast cadence)
     Slit: 2h
FOV along the slit: about 100h
     Exposure: 20 s
     Exposure delay: 0
     Spectral lines: covering cooler temperatures like He II, O V, Fe IX and so on

 other participating instruments
            H alpha and Ca II 854.2 nm line spectral data
            FOV: 16h x 40h at the cadence < 18 s  
             Line-of-sight magnetograms at the cadence of 1 min

Time period of proposed observations:

We wish to carry out a minimum of 10 days during the period of July 1 to August 31, which is the best observing season of BBSO. It is not necessary for observations to be on consecutive days, but our preference is at the two periods, if possible: 2011/07/11/-2011/07/15 and 2011/08/15-2011/08/19.

We need enough number of observing days to ensure the best seeing of BBSO and to cover different targets.  

Time window in day: The best time of coordinated observations each day is UT 18:00-20:00. we request a continous observation for at least 1 hour each day.  Interruptions are NOT allowed over the observing periods.

Target of interest:
Our target will be on-disk quiet Sun, near-limb quiet Sun, AR plage, and sunspots.
One or two target will be observed each day. Each target should be followed for longer than 1 hour without interruption.

Crucial is to have high cadence, say < 20 s in the spectral data. Since shocks may be frequent, it is not important to have a large field of view. Nevertheless field of views should be big enough to ensure the overlapping of fields of view of different instruments, say 20h x 50h.  
Mostly required Hinode instruments:

  SOT Ca II H filter

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