2. A complete study of magnetic flux emergence, interaction, and diffusion should take into account some “anomalies” In the solar photosphere we can observe large-scale flux concentrations sunspots (umbrae & penumbrae) small-scale flux concentrations pores, ephemeral regions, bright points … Magnetic flux emergence

3. but also: orphan penumbrae and naked sunspots Sunspot: typical structure Umbra Penumbra Penumbral filaments Bright dot

4. 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)

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

6. 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

7. Orphan penumbrae: 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)

8. Answer: evolution and spectropolarimetry LARGE orphan penumbrae in NOAA 11089 Zuccarello et al., ApJ, in press SMALL orphan penumbra in NOAA 11391 Guglielmino et al., ApJL, in press

9. NOAA 11089 Visible from 2010 July 20 to July 30 SDO – DOT – HINODE observations: July 22-24, 2010 Recurrent AR (5 passages on the solar disk)

10. SDO full-disk observations

12. The orphan penumbrae are visible for more than 48 hours and are larger than umbra regions The structures appear to fragment during their evolution These observations clearly 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

13. 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)

14. 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

15. HINODE datasets Filtergrams Broad-band – G-band (4305 Å) – Ca II H (3968.5 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 – 6301.5 Å and 6302.5 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

16. 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

17. Stokes Q, U, and V profiles exhibit a very asymmetric shape in individual points of the orphan penumbra Stokes I has often an asymmetric, broadened profile in these points These asymmetries indicate the presence of a multi- component magnetic atmosphere in these pixels, that suggests the presence of differently oriented field lines along the line of sight “uncombed” structure!!!

18. 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

19. HINODE: peculiar motions Peculiar plasma flows are cospatial with the western orphan penumbra: a central upward motion and downflows at the edges of the structure, with max values at about -4 km s -1 / +6 km s -1 These motions last for ≈ 8 hours, and decrease in time  The upflowing region seems to fragment the penumbra  Downflows are found in the structure until the end of Hinode observations These steady motions are interpreted as evidence of Evershed flows in the orphan penumbra filaments

20. HINODE: magnetic configuration The penumbral filaments of the orphan penumbrae connect regions of opposite magnetic polarity The western orphan penumbra has an average magnetic field of ≈ 1000 G, with a maximum of ≈ 1800 G, decreasing with time This structure lies above a PIL, with a maximum horizontal field of ≈ 1500 G The azimuth angle in the region is very homogeneous Magnetic field lines show a “direct configuration”, being almost perpendicular to the PIL and following the positive-negative direction

21. HINODE/SP: parameters

22. Higher atmospheric counterpart 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 11089 (= NOAA 11100) has a filament above a highly sheared PIL – no clear correlation with the presence of the orphan penumbrae

23. NOAA 11391 Visible from 2012 January 3 to January 13 SDO – HINODE observations: January 10-12, 2012 Decaying AR (2 passages on the solar disk)

24. 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

25. HINODE datasets Filtergrams Broad-band – G-band (4305 Å) – Ca II H (3968.5 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 – 6301.5 Å and 6302.5 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

26. Photospheric evolution: G band

27. HINODE/SP: parameters

29. HINODE: results The penumbral filaments form after the emergence of an ephemeral region, that gives rise to two pores The emergence zone has upflow 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 leading spot of the AR The region has an average field of ≈ 1000 G and lies above a S-shaped PIL, along which line-of-sight motions of about ±2 km s -1 are observed (both inversion and Doppler) No evidence of a flux rope above the structure

30. Chromospheric evolution: Ca II H 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

31. Summary NOAA 11089 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 11391 show the presence of penumbral-like filaments near the leading sunspot, in a region of polarity inversion The combination of the horizontal fields of emerging Ω-loops and an overlying canopy can give rise to the observed structures

32. Orphan penumbrae: 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)