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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0184

Center-to-limb variation of G-band intensity power suppression at the sites of fine-scale features

plan term


@ @


 name : Chitta, Jain, Kariyappa @  e-mail : pradeepch[at]iiap.res.in

contact person in HINODE team

 name : Katsukawa @  e-mail : yukio.katsukawa[at]nao.ac.jp

 abstract of observational proposal
Small scale magnetic elements on the solar disk can be identified with the localized bright regions when observed in high resolution G-band and Ca II H line. These bright regions have the potential to be used as diagnostic tools to probe the dynamics and interaction of small scale magnetic fields in which they are embedded. It is now becoming increasingly possible with the use of good quality, high-resolution Hinode data to study the effects of magnetic field on intensity and velocity oscillations in these fine structures. In this context, we recently investigated, using the Hinode data, the observational evidence of the interaction of acoustic waves and small-scale magnetic fields (Chitta, L. P, Jain, R & Kariyappa, R., 2010, in preparation) in quiet sun near the disk center. Our study suggests that both intensity and acoustic oscillations are suppressed in high magnetic field regions and are likely to be dependent on the sizes of the interacting structures. We also find that the measured ratio of acoustic power at 3.3 mHz for high to low magnetic field is in the range of 0.7 | 0.8. However, further work is needed to get an insight on the magnetic field inclinations in magnetic structures and the mechanisms of localised heating in the solar atmosphere. We therefore, would now like to extend our study to investigate the following two aspects in detail:

EHow the ratio (magnetic to weak magnetic) of powers of intensity oscillations at different frequencies are effected by the presence of magnetic field@at various longitudes and see if any center-to-limb variation in the ratio@of powers exists.

EThe variation of power ratio with respect to the strength and size of the@magnetic structures and their comparison at different longitudes.

 request to SOT
Instruments: Hinode/SOT FG & SP

Observables: Intensity observed in G-band and line of sight magnetic field. Full
vector magnetic field measurement is certainly more useful

FG: G-band 1024x1024, no sum (55hx55h), 16 sec cadence, 84mins at each pointing

SP: Deep map 512x512 (82hx82h), One scan at each pointing during the G-band observational run at that pointing. Start times for FG and SP scan should be as close as possible. ˆObservations are to be obtained starting from the center to the limb in a direction opposite to the Sunfs rotation to ensure that we are probing different regions on the solar disk.

 request to XRT

 request to EIS

 other participating instruments
Time period of proposed observations / Time window in day, if required. The observations should span over a period of 6 | 7 days to ensure that we are observing at different features. It is not necessary for observations to be on consecutive days. No specific time window. Any short interruptions should be avoided during observations.

Estimated Telemetry
FG: 340Mbits/hour ~ 1.4hours = 476Mbits
SP: 340 Mbits / scan
Total: 816 Mbits / pointing
For 11 pointings: 816 ~ 11 = 8976 Mbits

Target of interest
Quiet sun covering networks

Required Hinode instruments, and priority of observables
Instruments: Hinode/SOT FG & SP
Observables: Intensity observed in G-band and line of sight magnetic field. Full
vector magnetic field measurement is certainly more useful

pointing: The span of observations should cover the region with
(930h, 0h), (870h, 0h), (760h, 0h), (680h, 0h),
(415h, 0h), (0h, 0h), (|415h, 0h),
(|680h, 0h), (|760h, 0h), (|870h, 0h), (|930h, 0h)

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