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HINODE Operation Plan (HOP)

accepted on

20-jun-07


 HOP No.

 HOP title

HOP 0024

Prominence Mass Composition and Variability Study

plan term

@ @

proposer

 name : G. Kilper, H. Gilbert, T. Kucera, D. Alexander @  e-mail : garyk [at] rice.edu

contact person in HINODE team

 name : T. Berger @  e-mail : berger[at]lmsal.com

 abstract of observational proposal
To study the relative abundances of hydrogen and helium in prominences and
find trends in its spatial distribution and variability over time by
measuring the continuum absorption due to photoionization for EUV
observations (e.g. JOP63, ref:Kucera98, ref:Gilbert05) and the absorption
in H-alpha (6563 A) and He I (10830 A).

This study is primarily motivated by our findings from analyzing
absorption due to filaments in H-alpha and He I MLSO observations
(ref:Gilbert07).  The results of that study and the preliminary results of
our current, ongoing analysis of continuum absorption in archived EUV data
from CDS, EIT, and TRACE show similar trends: stable (i.e. relatively
unchanging) prominences have a relative helium surplus (compared to the
average ratio of He to H) in the lower part and a relative helium deficit
in the upper part, while more variable prominences (including those that
are pre-eruption) have a homogenized spatial distribution of helium
relative to hydrogen.

Further study needs to be done to find the scale heights of the H and He
distribution and the time scales over which they change, but the ability
to study more highly varying material requires co-temporal observations
with better cadence and spatial resolution (via the newer observatories)
than is currently available in the archived data of CDS, EIT, and TRACE.
Note that coordinated observations are necessary to compare the
simultaneous distributions of H0, He0, and He+.

 request to SOT
SOT:  Observe the prominence region at all wavelengths in BFI
(218"x109", .0541 arcsec/pixel) and NFI (328"x164", .08 arcsec/pixel) with
full FOV every two minutes.  For larger prominences that cannot fit into
the field of view, it may be more useful to combine two or four
observations to construct a mosaic image of the entire prominence.

 request to XRT
SOT:  Observe the prominence region at all wavelengths in BFI
(218"x109", .0541 arcsec/pixel) and NFI (328"x164", .08 arcsec/pixel) with
full FOV every two minutes.  For larger prominences that cannot fit into
the field of view, it may be more useful to combine two or four
observations to construct a mosaic image of the entire prominence.

 request to EIS
EIS:  Observe the prominence region with 1.0 arcsec/pixel resolution
primarily in Fe XI (188.23 A), Fe XII (195.12 A), Fe XIII (202.04 A), He
II (256.32 A), Fe XIV (264.79 A), and Fe XV (284.16 A), while including
other lines to fill out the temperature range of the observations (use the
same Linelist as EIS Study-42).  The 266 arcsec slot should be used with
60 sec exposure time and a sit-and-stare raster to create a 266"x512"
image every minute.

 other participating instruments
SOHO-EIT, SOHO-CDS, SOHO-MDI, TRACE, STEREO-EUVI, Hinode-SOT, Hinode-EIS,
MLSO

 remarks

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