HOP list   Monthly Events

HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0384

The role of vertical magnetic fields in active regions

plan term


@ @


 name : Garcia Rivas @  e-mail : marta.garcia.rivas[at]asu.cas.cz

contact person in HINODE team

 name : DeRosa, Shine @  e-mail : derosa[at]lmsal.com, shine[at]lmsal.com

 abstract of observational proposal
Main Objective: To analyse the vertical component of the vector magnetic field in active regions. To study the evolution of the magnetic properties on the boundary of pores and umbrae, if any.

Scientific Justification: Jurcak criterion is an empirical law that states that the boundary between umbra and penumbra is defined by a constant vertical magnetic field in stable sunspots (Jurcak et al. 2018). This means that it exists a critical vertical magnetic field (Bcrit), independent of other conditions such as sunspot size, solar location or solar activity, that completely changes the convective motion on the solar surface. Vertical magnetic fields (Bver) stronger than Bcrit only allow umbral convection. However, umbrae and pores with Bver weaker than Bcrit are unstable and prone to be disintegrated by convective motions (Schmassmann et al. 2018).

Jurcak criterion was defined after statistically analising 88 sunspot scans from Hinode/SOT-SP. This criterion motivates wider analyses of the influence of the vector magnetic field on solar convection. In ourground-based observations (GREGOR, Tenerife, Spain) we aim to characterise solar granulation in terms of the vector magnetic field. The coordination with Hinode/SOT-SP will let us compare space-based to ground-based spectropolarimetric observations and to Jurcak's statistics.

 request to SOT
SOT-SP is required. Normal mode maps. FoV of 164" x 164"

 request to XRT

 request to EIS

 other participating instruments

Dates: Start: 03/09/2019 End: 11/09/2019

Time window: Observations at GREGOR telescope will run from 07:00 UT to 15:00 UT. During that time window, whenever Hinode/SOT-SP is available.

Target(s) of interest: Target of opportunity. The main target are active regions. From emerging active regions to pores and sunspots.

Previous HOPs: None

HOP list   Monthly Events