HOP 0160

abstract of observational proposal

The main aim of this HOP is to provide the community with a *consistent* set
of observations during the entire lifetime of an active region (AR). The HOP can be regarded as successful if at least a few ARs have been observed. Two types of observational approaches might be needed, depending on the lifetime
and production rate of ARs in the near future. One observation per day or every two days will be sufficient.

The objective is to measure *Doppler-shifts* and line profiles during the evolution of an AR. In particular, blue-shifts, where long exposures are needed (Del Zanna 2007 1st Hinode meeting). However, a large number of lines has been added to measure coronal densities (from Fe XII, Fe XIII, Fe XIV), and possibly temperatures.

An additional aim is to measure the Ne/Si abundance as a function of AR lifetime, by combining EIS with SOHO CDS observations. Variations of Ne/Mg were found from Skylab (Widing & Feldman, 2001, ApJ 555, 426), and if confirmed
would have important implications for our understanding of the coronal abundance variations.

request to EIS

The FOV MUST BE large enough to cover the entire AR and some boundary region around it.

One new EIS study has been designed and now modified: GDZ_300x384_S2S3_40s
2" slit, 3" step, covers 300" in less than 1 hour. 380" extraction along the slit means 360" co-spatial data from the SW and LW channels.

40s exposure will saturate in some points the Fe XII line, however thw Fe XII 192.4 line is also included in the study.

Selection of lines: a few spanning all temperatures including core lines, lines to deblend them, and flare lines: He II (core), Fe VIII (Si VII, Mg V, VI, VII), Fe X, Fe XI, Fe XII (core), Fe XIII, Fe XIV, Fe XV, Fe XVI, Ca XVII(core) Fe XVII, Fe XXIII, Fe XXIV.

Details of EIS Study Definition:

ACRONYM: GDZ_300x384_S2S3_40s

OBJECTIVE:

Perform a large (300x384) sparse (3") raster over an active region
with the 2" slit and long exposures (40s).
TARGET : Active region
EXPOSURE TIME : 40s
RASTER : Scanning
SLIT : 2"
STEP_SIZE : 3"
FOV : 300"x384"
SPECTRAL WIND.: 25
DATA COMP. : DCPM
RASTER DURATON: 1h14m
DATA volume : 182 Mbits
LINES : Fe VIII, IX, X,XI,XII,XIII,XIV,XVI,XVII, XXIII, XXIV
O V, Mg VI, VII, Ca XIV, XVII

POINTING: a quiescent active region observed across the disk.

INSTRUCTION TO PLANNERS:
It is important to inform CDS planners of the EIS pointing so that the study
ARCONT (ID 11, VAR 105) containing the Fe XIX and Ne VI lines is run.

other participating instruments

SOHO/CDS
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It is desirable but NOT ESSENTIAL to have simultaneous NIS observations which contain the Fe XIX line and possibly O,Ne lines for elemental abundance studies. Suggested study:

ARCONT STUDY_ID 11, VAR 105 DURATION 44m 35s exp. FOV=240x240

Magnetograms and context EUV images (He II, coronal, 10sec cadence) will be obtained from SDO/AIA.

remarks

TARGET
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As simple as possible bipolar with possibly one Sunspot. Small or medium-size so it would fit a 300 arc sec x 360 arc sec field of view and with a chance that it will be visible in the following rotation.

The AR should be followed as it crosses the disk until the West limb with
a minimal **consistent** set of EIS+ (XRT,SOT) studies. One run of the GDZ_300x384_S2S3_35s study every other day would be sufficient. If the AR extends more than 300" along E-W, the EIS study should be run twice with two pointings.

1st Approach
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The Observations should be starting at the EAST limb with some off-limb coverage. Pointing at an AR, which just started to develop when it is at the East limb. Requires coordination with STEREO, i.e. use STEREO to identify a newly-formed AR which will appear at the east limb to Hinode.
Why: some general features such as AR moss are more clearly observed at the limb (to reduce foreground projection effects). Structures such as cusps are much better recognised at the limb. Also in case of a large flare current sheets would be better observed. Finally, loop height is easier to measure.

Planners should figure out, about after two weeks, and taking advantage of the STEREO information, if the AR will be visible again at the east limb. If yes, then continue the same set of minimal observations until the AR is so dispersed that there will be weak emission in XRT.

2nd Approach
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Second type of target: one AR which forms in an area just East of the meridian, so when it reaches the meridian is only 1-3 days old. The aim in this case is to start observing as soon as an AR forms. The observing sequence is the same as above.

OBSERVING PERIOD: This is a ToO.