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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0090

Joint Study of XRT, CaIIK jets and Quiet Sun H-alpha Surges

plan term


@ @


 name : Yurchyshyn,Abramenko, Shibata, Uritsky @  e-mail : vayur[at]bbso.njit.edu

contact person in HINODE team

 name : Ichimoto @  e-mail : ichimoto[at]kwasan.kyoto-u.ac.jp

 abstract of observational proposal
Plasma jets, observed as X]ray jets with Hinode XRT telescope (Cirtain et al. 2007), UV jets (Brueckner & Bartoe 1983; Alexander & Fletcher 1999) and chromospheric jets (SOT Ca II H spectral line,  Katsukawa et al., 2007; Shibata et al. 2007) are thought to be a manifestation of reconnection process in the solar atmosphere. The fundamental physical parameters of Hinode X]ray jets are presented in (Savcheva et al. 2007). At present, the XRT jets were identified and described only in polar coronal holes. It is suggested that the occurrence of jets depends on the reconnection of an emerging magnetic bi]poles with a system of open magnetic field lines. Since quiet sun regions predominantly hosts closed magnetic loops (although open field lines could be present, too) it is expected that X]ray jets may be less frequent here. Besides, because of their week X]ray emission and relatively small size, X]ray jets may be difficult to distinguish against bright disk background of quiet sun areas.

We suggest that events, associated with XRT jets, could be also observed on the solar disk as a bright loops with cusps or loops with blobs (as shown in figure on the left. Image credit: NASA). The pointy shape of those loops suggests that they may be associated with reconnection and/or open (extended) field lines. We propose to consider spiky loops and cusps as an indication of a reconnection between a bi]pole and the open field and, therefore, jets may be present at one end of a flaring loop (Canfield et al. 1996). Also, it is not excluded that quiet sun areas outside coronal holes may as well have numerous inclusions of open field lines as evidnced by EIT 285A images (right). This partial view of EIT 285A sun shows that a significant fraction of quiet sun is dark, suggesting that open field lines might originate from it (coronal holes are dark as well, only larger).

Association between X]ray jets and H surges has been addressed in earlier works by Yokoyama & Shibata, 1995; Canfield et al. 1996), who showed both theoretically and observationally that cold chromospheric plasma may accelerate during reconnection between anemerging flux and the coronal field and be observed as H surges adjacent to the X]ray jet. However, a statistical study of X]ray jets and H surges has not yet been conducted. A coordinated observational campaign between Hinode XRT and H telescopes (as well as other wavelength such as those used in TRACE experiment) would be beneficial for better understanding of the underlying dynamics of magnetic fields.

 request to SOT
Hinode SOT Ca II H observations
Ca II H observations will provide information on the dynamics of chromospheric bright points seen in inter]granular lanes. We need ]2 min cadence observations in the Ca II H line. Field of view 105x105arcsec should be within the XRT field of view.

Hinode SOT FG observations
1min I and V Stocks parameters measured in Na I 5896A spectral line over the area co]spatial with the SOT Ca II H and XRT field of view. Below is a summary of required SOT observation. The 320 sec cadence is marginally satisfactory and 120]180 sec cadence would be highly appreciated.

 request to XRT
Hinode XRT Observations
We are looking for high resolution and XRT Al]poly data acquired at the disk center. The desired time cadence is about 1 min. Field of view 394x394 arcsec.

 request to EIS

 other participating instruments

Time period of proposed observations

Since observations with BBSO Halpha telescope are made every day, weather permitting, we are very flexible in choosing of the period of observations. We would like to request at least 5 days of observations. It is not necessary for observations to be on consecutive days.
The minimum observation interval is requested to be 1 hour. BBSO experiences best seeing during our morning ours, therefore we would strongly prefer our coordinated observations to be within 15:00 – 1600UT time window. Short interruptions are allowed.

Target of observations: quiet Sun area at the disk center with XRT jets and/or cusp like loops.

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