A complete study of magnetic flux emergence, interaction, and diffusion should take into account some “anomalies” In the photosphere we can observe flux concentrations over many spatial scales sunspots, pores, ephemeral regions, granular loops … but rare observations also show: orphan penumbrae and naked sunspots Magnetic flux emergence 2

Orphan penumbrae are bundles of filamentary structures, very similar to sunspot penumbral filaments, but that are not adjacent to any sunspot umbra Why “orphan penumbrae”? The orphan penumbra shows the same motions observed in the sunspot penumbra Zirin & Wang (1991) 3

Formation mechanism a)photospheric manifestation of a flux rope trapped in the photosphere (Kuckein et al., 2012a,b) b)the result of an emerging Ω- loop trapped in the photosphere by overlying canopy fields (Lim et al., 2013) c)the effect of submerging horizontal field in flattened Ω-loops (Jurčak et al., 2014) 4

Models of penumbral filament formation MHD simulations (Rempel 2012): magnetoconvection in presence of horizontal fields is able to form penumbral structures when a magnetic canopy overlies the flux region 5

Observations of penumbral filament formation Romano et al. (2013, 2014) find a 3 " -5 " width annular zone around a pore, a few hours before the penumbra formation magnetic field with uncombed structure several patches (≈1 " ) with upflows and rather vertical fields The penumbral filament formation results from the bending of the field lines of the magnetic canopy overlying the pore 6

Answer: evolution and spectropolarimetry LARGE orphan penumbrae in NOAA Zuccarello et al. (2014) ApJ, 787, 57 SMALL orphan penumbra in NOAA Guglielmino et al. (2014) ApJL, 786, L22 7

NOAA Visible from 2010 July 20 to July 30 SDO – DOT – HINODE observations: July Recurrent AR (5 passages on the solar disk) 8

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SDO full-disk observations The orphan penumbrae are visible for more than 48 hours and are larger than umbral regions The structures fragment during their evolution These SDO observations show that:  the eastern orphan penumbra is formed as the main sunspots lose part of their penumbrae  the western orphan penumbra is forming independently In both the structures the SDO movie indicates several episodes of flux emergence Peculiar motions are found in the orphan penumbrae: – upflows in their central regions 10

DOT observations Note the sequence of bright granules at the border of the orphan penumbra Note the chromospheric filamentary structure above the orphan penumbra In the chromosphere we find upflows in the central part of the structure 11

HINODE/SP observations Maps of physical parameters from the standard M-E Hinode CSAC inversions (level 1.5 data) Azimuth ambiguity was solved using the Non-Potential Field Calculation (Georgoulis, 2005) Line-of-sight (LOS) velocities were calibrated assuming plasma at rest in umbrae Raster scans aligned through cross-correlation algorithms Asymmetry in Stokes profiles “uncombed” structure!!! 12

HINODE/SP evolution Red contours: Polarity Inversion Lines (PILs) Dark blue/blue contours (upflow): -3/-1.5 km s -1 Red/light red contours (downflow): +3/+1.5 km s -1 13

HINODE/SP evolution Peculiar plasma flows are found in the western orphan penumbra: a central upward motion and downflows at the edges, max values -4 / +6 km s -1 Flows last for ≈ 8 hours and decrease in time  The upflowing region seems to fragment the penumbra  Downflows are observed until the end of Hinode observations Evershed flows in the orphan penumbra filaments? This structure lies above a PIL, with a maximum horizontal field of ≈ 1500 G decreasing in time Magnetic field lines show a “direct configuration”, with a very homogeneous azimuth angle 14

NOAA Visible from 2012 January 3 to January 13 SDO – HINODE observations: January Decaying AR (2 passages on the solar disk) 15

G band: photospheric evolution 16

HINODE/SP parameters 17

Ca II H: chromospheric evolution Lim et al. (2013) found a magnetic canopy over the filaments and an Hα brightening at one of the edge of the structure Indirect confirmation of the presence of the magnetic canopy –interaction between the positive patch of the emerging bipole and the plage negative field –presence of a strong Ca II H brightening likely due to magnetic reconnection between these two flux systems 18

HINODE results The penumbral filaments form after the emergence of an ephemeral region, that gives rise to two pores The emergence zone has upflows of ≈ 1 km s -1 and an average horizontal field of ≈ 650 G The penumbral filaments form after about 2 hours and slightly move eastwards with respect to the AR The region has an average field of ≈ 1000 G and lies above a S-shaped PIL, where line-of-sight motions of about ±2 km s -1 occur (inversion and Doppler) No evidence of a flux rope above the structure Interaction with an overlying canopy 19

Summary NOAA shows the presence of large areas – 23" x 5" – covered by orphan penumbrae that have a lifetime of days and fragment during their evolution The magnetic field lines have different inclinations along the line of sight, indicating an uncombed structure The orphan penumbrae show upflows in the central part and downflows at the edges, lasting for hours and decreasing in time The magnetic field vector has a strong horizontal component in the western orphan penumbra, that lies above a PIL NOAA show the presence of penumbral-like filaments near the leading sunspot above a PIL Above these structures magnetic reconnection with the overlying canopy fields occurs at low chromospheric levels 20

Formation mechanism a)photospheric manifestation of a flux rope trapped in the photosphere (Kuckein et al., 2012a,b) b)the result of an emerging Ω- loop trapped in the photosphere by overlying canopy fields (Lim et al., 2013) c)the effect of submerging horizontal field in flattened Ω-loops (Jurčak et al., 2014) The combination of the horizontal fields of emerging Ω-loops and an overlying canopy can give rise to the observed structures 21

Orphan penumbrae: properties Orphan penumbrae act like bridges that connect different small groups of pores They are identified as rising magnetic flux tubes, forming filaments in the upper atmo- spheric layers Kuckein, Martínez Pillet & Centeno (2012) found an orphan penumbra below a chromospheric filament 22

High-resolution osbervations Lim et al. (2013) studied this AR using observations carried out at the New Solar Telescope, in the TiO band (705.7nm) and in the Hα blue wing They found an “orphan penumbra” near the large trailing sunspot of the AR, with overlying fields 23

G-bandRed continuum HαHα DOT datasets Spatial resolution 0".2 (despeckle algorithm) Imaging in G-band / Red continuum Spectroscopy in H α (Gaussian fit: velocity) 24

HINODE datasets Filtergrams Broad-band – G-band (4305 Å) – Ca II H ( Å) Narrow-band – Na I D1 (5896 Å) Stokes I&V from 22/07/2010 – 21:06 UT to 24/07/2010 – 08:45 UT FOV: 188" x 111" Spectropolarimetry Fe I pair – Å and Å from 22/07/2010 – 22:16 UT to 24/07/2010 – 02:03 UT FOV: 120" x 120" Pixel scale: 0.32" Fast mode 18 raster scans 25

HINODE/SP: parameters 26

Higher atmospheric counterpart DOT Hα images do NOT show any filaments above the orphan penumbrae Also AIA images at 304 Å, referring to the lower corona, do NOT show the presence of any filaments above the orphan penumbrae in the following hours After a solar rotation, the recurrent AR NOAA (= NOAA 11100) has a filament above a highly sheared PIL – no clear correlation with the presence of the orphan penumbrae 27

HINODE datasets Filtergrams Broad-band – G-band (4305 Å) – Ca II H ( Å) Narrow-band – Na I D1 (5896 Å) Stokes I&V from 10/01/2012 – 15:34 UT to 11/01/2012 – 02:07 UT FOV: 188" x 111" Spectropolarimetry Fe I pair – Å and Å from 10/01/2012 – 15:34 UT to 10/01/2012 – 18:35 UT FOV: 297" x 164" Pixel scale: 0.32" Fast mode 2 raster scans 28