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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0247

Hot plage/AR moss

plan term

@ @


 name : Testa, De Pontieu, Young @  e-mail : ptesta[at]cfa.harvard.edu

contact person in HINODE team

 name : Testa @  e-mail : ptesta[at]cfa.harvard.edu

 abstract of observational proposal
Determine the characteristics of temporal variability in moss emission, and correlations between variability at different temperatures, using IRIS, Hinode, and AIA.

Scientific Background:
The spatial and temporal variability of the emission of active region moss provides stringent constraints on the characteristics of heating events (e.g., Martens et al. 2000). Recent moss observations with the Hi-C (High resolution coronal imager) sounding rocket in a EUV narrow band around 193A at high spatial (~0.3 arcsec) and temporal (~5.5s) resolution, has revealed in some moss regions variability on timescales down to ~15 s, significantly shorter than the minute-scale variability typically found in previous observations of moss (Testa et al. 2013). The Hi-C and SDO observations of these events suggest that they are signatures of heating events associated with reconnection occurring in the overlying hot coronal loops, i.e., coronal nanoflares. The Hi-C rocket only produced few minutes of data, therefore preventing a detail study of the statistical properties of these events.

IRIS provides imaging and spectral observations at high spatial and temporal resolution at FUV and NUV wavelengths, and allows to study, together with Hinode and SDO, the response of the lower atmosphere in hot loops to heating episodes.  Coordinated observing of Hinode with IRIS provides the opportunity to characterize, through both imaging and spectroscopy, the variability of AR moss with large temperature coverage (low TR to corona), high spatial resolution, and spectral diagnostics at TR (IRIS) and coronal (EIS) temperatures.

 request to SOT
NFI:  magnetograms with high SNR, using ROI # 2 to shift by 25 arcsec towards the lower part of the CCD to have best image quality.  

FG 0x4a6   HOP236 Shless Na IV 61x82", 32 s, Ca, ROI 2:  Na FOV = 61x82 arcsec, cadence = 36 sec, telemetry usage = 280 Mbits/hour

Note: margin factor
  FG 0x4a6 --- 1.15

 request to XRT
XRT: high cadence obs (~10s) with 384x384 fov, single filter (thin-Be;
    or 2 filters, if telemetry allows, as long as the cadence in each filter
    is ~10s)

If telemetry allows, please use XOB 19FD (created for this IHOP) and use FLD17 (which reduces the cadence of the flare patrol images to 80s) for the timeline when you run HOP 247 (and revert to the usual FLD table for timelines not running this HOP).

 request to EIS
Please run 'Fast_moss_scan' (ID 511):
  Slit: 2"
  No. of steps: 3
  Step size: 3"
  Lines: He II 256.32, Fe VIII 194.66, Fe X 184.54, Fe XI 188.22, Fe XII 195.12, Fe XIII 202.02, Fe XIII 203.82, Fe XV 284.16, Fe XVI 262.99
  Slit length: 180"
  Exposure time: 5s

 other participating instruments
Request to IRIS:

IRIS should run a large sit-and-stare, with exposure times of 2 or 4 sec, and slit jaw images in the 1400, with rotation tracking. The cadence in 1400 SJI should be about 10s (the IRIS OBS can also include 2796 SJI). OBS 3820257453 is a good observing program for the purpose of this study. If choosing another OBS please select a medium or large linelist (not a flare linelist). To ensure overlap between IRIS and EIS, IRIS should be rolled at a small angle (5 deg).

The target should be moss at footpoints of hot (i.e., bright in AIA 94A and XRT) loops in AR at or close to disk center.  

Minimum duration of each run should be ~1 hour, avoiding SAA; longer runs are desirable when telemetry allows.

Please contact HOPs proposers for target coordinates.  If the SAA-free periods are not used, then coordination between the planners to avoid SAA in both spacecraft is necessary.  IRIS SAA-free times are approximately 11-15 UT and 23 - 04 UT.

Note that the SOT FOV is internally shifted to the South by 25 arcsec, independent of the usual SOT offset that is well-known to CPs and COs.  THEREFORE, HINODE POINTING (corrected for the usual SOT offset) SHOULD AIM 25 ARCSEC NORTH OF THE ACTUAL TARGET COORDINATES USED BY IRIS.

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