HOP 0199

abstract of observational proposal

Our observational objects are 1) formation of penumbral filamentary structures, and 2) the origin of moving magnetic features. Recent observations using TiO broad-band equipped at New Solar Telescope at Big Bear Solar Observatory discovered photospheric elongated features on sub-granular (<1” in width) scale formed at the tip of dark penumbral filaments (Lim et al. 2011, ApJ submitted). Such features were associated with small-scale emerging and fast moving (> 4kms-1) magnetic features (MMF) at the boundary of the penumbra. Such fine-scale photospheric counterparts of MMFs have not been frequently observed due to the limitation of spatial resolution. NST/TiO observation showed several examples of such features at the boundary of penumbra. The TiO data with high spatial resolution (0.0375”/pixel) and time cadence (15 s) showed even detailed morphology of such photospheric counterparts of MMFs on sub-granular scale. We are aim to understand the formation mechanism of such elongated, fast-moving features, and their role in the formation of penumbral filamentary structures. For this aim, magnetic field information along with Doppler velocity measurement should be accompanied with NST/TiO observation. Since observed elongated features are small-scale (< 1” in width) and have short observable lifetime (<20mins), both high spatial and temporal resolution is required.

request to SOT

a. SOT/FG IV FOV covering whole area of interested active region, high time-cadence is the priority of observables, 0.16”/pix of spatial resolution is preferred

b. SOT/SP minimum FOV scan that covers penumbra and its outer region (in order to reduce the scanning time and increase the time-cadence)

remarks

Target of interest: Sunspot with penumbra on-disk & pores with proto-type penumbra on-disk

Observation period: 7 days somewhere between 29 August and 30 September. Earlier and consecutive dates (such as, say, 29 Aug to 4 Sep) are preferred.

Observation time: 1800UT- 2000UT (no gaps) with BBSO/NST

Data volume estimates: in total, about 1,8Gbits per 2-hr run

1)NFI Doppler- & Magnetograms, 164"x164", 2x2, 64-sec cadence -> 510 Mbits/hr
2)SP Normal maps, 19"x82", 0.16" pixel, 10-min -> 68 Mbits