HOP list   Monthly Events

HINODE Operation Plan (HOP)

accepted on

23-jun-11


 HOP No.

 HOP title

HOP 0195

CORE: ToO: Quiet Sun and facular regions properties. Coordinated observations with SST/DOT

plan term

ToO
2011/08/06-2011/08/19

@ @

proposer

 name : Criscuoli, Ermolli, Giorgi, Guglielmino, Zuccarello @  e-mail : serena.criscuoli[at]oa-roma.inaf.it
ilaria.ermolli[at]oa-roma.inaf.it
fabrizio.giorgi[at]oa-roma.inaf.it
sgu[at]iac.es
francesca.zuccarello[at]oact.inaf.it

contact person in HINODE team

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

 abstract of observational proposal
The main goal of this proposal is to plan coordinated observations between HINODE instruments and the SST and DOT telescopes on La Palma (Canary Islands). These observations will produce a comprehensive data set of high precision, high resolution spectro-polarimetric and imaging measurements for the study of
the magnetic fine structure of the solar atmosphere and its effects on solar irradiance variations.

In particular, we propose to investigate the photometric and physical properties of small-size magnetic elements observed on quiet Sun and facular regions. Analysis of the radiative emission measured on the observed regions, together with results derived from spectro-polarimetric inversions, and outcomes of multi-dimensional MHD simulations, will allow us to depict the thermal stratification in regions with different flux element aggregations and improve our understanding of the mechanisms that drive irradiance variations.
Recent results of solar irradiance measurements, both spectral and total emission, have called current knowledge on the matter into question (Domingo et al. 2009; Froehlich 2009; Harder et al. 2009; Steinhilber 2010; Ball et al. 2011; Krivova, Solanki, Schmutz 2011). This is mainly due to lack of detailed knowledge of the temperature stratification in magnetic regions and contribution of quiet Sun regions to total irradiance variations. Indeed, variations of spectral irradiance have been proposed to reflect temporal variations of the stratification of magnetic features. This hypothesis is supported by results from observations of small-size magnetic features (Ishikawa et al. 2007) and flux tube models recently developed (Criscuoli & Rast 2009), which show that physical properties of magnetic elements depend also on their environment and their degree of aggregation. Nevertheless, attempts to reproduce irradiance with constraints derived from these kind of measurements and flux tube models are still lacking. On the other hand, quiet Sun regions have been also proposed to affect total irradiance variations, but evaluation of their contribution, mostly due to effects of unresolved magnetic fields, is particularly controversial.

To contribute to this topic of research we plan to analyze observations acquired with CRISP at FeI 557.6 and FeI 630.2 nm, and with SOT/SP at FeI 630.2 nm on both quiet and facular regions. The analysis of the variation of the shape of the first line, which is insensitive to magnetic field but very sensitive to temperature gradients, on quiet and magnetic regions, and inversions of spectro-polarimetric data acquired in the second line, from both SST and HINODE, will allow us to investigate the physical parameters of the photosphere in the various regions.

In particular, comparison of results from spectro-polarimetric observations in the FeI 630.2 nm in various regions will allow us to investigate the variation of the properties of magnetic regions with their degree of aggregation. Comparison of results from this analysis with detailed spectral synthesis from multidimensional MHD simulations of the solar photosphere will improve our knowledge of the physical mechanisms that drive irradiance variations. The analysis of data contemporaneously acquired with DOT, imaging (approximately) the same FOV, will allow us to investigate the effects of small-size magnetic elements and of their aggregation on measurements of photometric properties of the quiet Sun and magnetic features at various atmospheric heights.
Joint observations with HINODEfs EIS and XRT for corona are also required, to provide us with complementary information to achieve our objectives.

Ball, W. T., Unruh, Y. C., Krivova, N. A., Solanki, S., Harder, J. W. 2011, A&A, 530, A71

Criscuoli, S. & Rast, M. 2009 A&A, 495, 621

Domingo, V.; Ermolli, I.; Fox, P.; Fröhlich, C.; Haberreiter, M. et al. 2009 SSRV 145, 337

Froehlich , C. 2009, A&A 501, L27

Harder, J. W., Fontenla, J. M., Pilewskie, P., Richard, E. C., Woods,. N. 2009, GeoRL 3607801

Krivova, N. A., Solanki, S. K., Schmutz, W. 2011, A&A, 529, A81
Ishikawa, R., Tsuneta, S., Kitakoshi, Y., Katsukawa, Y., Bonet, J.A.et al.2007 A&A 472, 911

Steinhilber, F. 2010, A&A 523, A39

 request to SOT
TARGET OF INTEREST: QUIET SUN PROGRAM (Main priority)

1. Select a position, near disc centre, away from an active region, but it would be acceptable an external area of a decaying active region. The selected area will contain some network and eventually a small facula.

2. Obtain filtergrams with BFI and NFI: G band and Ca II H at 2-min cadence when possible, without rebinning (binning just 1~1) or with binning and 2x2. A suitable FOV would be 54"~54". Images shutterless V/I 1~1 on MgI (517.27 nm), tuning at } 11.5 pm, are required, with cadence of 90 s (preferred cadence:
60s). These images will provide the radiative structures at different levels of the photosphere and the chromosphere.

3. Obtain magnetograms or spectropolarimetric maps with SOT/SP: if possible at or near the same time as the filtergrams in FAST MAP MODE, 1 map (approx. 45"~65") every 40min, as this is one of the modes that best suits the requirements with minimum storage and/or telemetry (120 Kb/sec).

TARGET OF INTEREST: FACULAR REGION PROGRAM

TARGET OF OPPORTUNITY: EVOLUTION OF MAGNETIC TOPOLOGY IN DECAYING ACTIVE REGIONS
Same request, with different pointing.

 request to XRT
TARGET OF INTEREST: QUIET SUN PROGRAM
Obtain images with C-Poly and Be-Med, cadence 1min, during the same time as for SOT. This will be used to study possible coronal magnetic fields and XBP, in Quiet Sun small features. FOVX = FOVY = 384".

TARGET OF INTEREST: FACULAR REGION PROGRAM

TARGET OF OPPORTUNITY : EVOLUTION OFMAGNETIC TOPOLOGY IN DECAYING ACTIVE REGIONS
Same request, with different pointing.

 request to EIS
TARGET OF INTEREST: QUIET SUN PROGRAM
Obtain slit images in chromospheric cold lines and low coronal lines (He II 256.32, O VI 184.12, Mg VII 278.39 and 280.75, Si X 258.37, Fe XII 195.12 as a reference). Cadence as high as possible, with a FOV large enough to cover 200"~300". 1/8 of total telemetry (40kbps) after compression.

TARGET OF INTEREST: FACULAR REGION PROGRAM

TARGET OF OPPORTUNITY: EVOLUTION OFMAGNETIC TOPOLOGY IN DECAYING ACTIVE REGIONS
Same request, with different pointing.

 other participating instruments
SST, DOT

 remarks
PERIOD
Observations will begin on 6th August 2011 and will end on 19th August 2011, during the period of the SST and DOT observations.

We require 4 hours per days, from 8:00 UT to 12:00 UT .

HOP list   Monthly Events