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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0377

Magnetic flux emergence during penumbra formation

plan term


@ @


 name : Romano, Guglielmino, Zuccarello, Yurchyshyn   @  e-mail : paolo.romano[at]inaf.it, salvatore.guglielmino[at]inaf.it, francesca.zuccarello[at]inaf.it, yurchysh[at]njit.edu

contact person in HINODE team

 name : Savage, Watanabe, De Pontieu @  e-mail : sabrina.savage[at]nasa.gov, watanabe.tetsuya[at]nao.ac.jp, bdp[at]lmsal.com

 abstract of observational proposal
Main Objective: Discriminating between two main scenarios for penumbra formation

Scientific Justification: Currently, there are two main explanations for penumbra formation. Leka & Skumanich (1998) suggested that emerging, horizontal field lines could be trapped and form a penumbra rather than continuing to rise to higher layers, due to the presence of the overlying magnetic canopy in the emerging region. In contrast, Shimizu et al. (2012) and Romano et al. (2013, 2014), based on their observations of signatures of penumbra formation around pores in the chromosphere appearing earlier than in the photosphere, suggested that the field lines of the magnetic canopy, already existing at a higher level of the solar atmosphere and overlying the pore, may be responsible for the formation of the penumbra if they sink down into the photosphere and below the solar surface. In order to discriminate between these two scenarios, we plan to perform a coordinated observing campaign with GST, Hinode and IRIS. Moreover, we aim to investigate also the physical mechanism which is able to trigger the Evershed flow in
the penumbral filaments during their settlement.

To this purpose, we have been allocated GST time on October 2019.
Our targets will be active regions during formation (if any) or pores.
Backup program: quiet-Sun flux emergence at disc center.

Leka, K. D., & Skumanich, A. 1998, ApJ, 507, 454
Romano, P., Frasca, D., Guglielmino, S. L., et al. 2013, ApJL, 771, L3
Romano, P., Guglielmino, S. L., Cristaldi, A., et al. 2014, ApJ, 784, A10  
Shimizu, T., Ichimoto, K., & Suematsu, Y. 2012, ApJL, 747, L18

 request to SOT
G-band and Ca II H filtergrams with 5/10 minute cadence, relevant to the photospheric and low chromospheric levels.  
Spectropolarimetric rasters along the Fe I 630.2 nm pair with one hour cadence in normal map mode, 1000X512 or 512X512

 request to XRT
Al/poly and Thin-Be active region program, 1 minute cadence

 request to EIS

 other participating instruments
IRIS requests:  
We have already contacted the IRIS team.
High datarate:  
OBS-ID 3620254071  
Medium datarate:  
OBS-ID 3620256071
Low datarate:  

Additional instrument coordination:  

Dates:  5-11 October 2019
Time window:  17-22 UT
Target(s) of interest:  Active regions. Pores. ToO: flaring active region.

Previous HOPs:  
HOP 0035

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