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Chromospheric Alfvénic Waves Strong Enough to Power the Solar Wind
Schrijver, C. J.; Ichimoto, K.; De Pontieu, B. +11 more
Alfvén waves have been invoked as a possible mechanism for the heating of the Sun's outer atmosphere, or corona, to millions of degrees and for the acceleration of the solar wind to hundreds of kilometers per second. However, Alfvén waves of sufficient strength have not been unambiguously observed in the solar atmosphere. We used images of high te…
Evidence for Alfvén Waves in Solar X-ray Jets
Weber, M.; Golub, L.; Kano, R. +11 more
Coronal magnetic fields are dynamic, and field lines may misalign, reassemble, and release energy by means of magnetic reconnection. Giant releases may generate solar flares and coronal mass ejections and, on a smaller scale, produce x-ray jets. Hinode observations of polar coronal holes reveal that x-ray jets have two distinct velocities: one nea…
Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection
Matsumoto, Takuma; Shibata, Kazunari; Nishizuka, Naoto +19 more
The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their veloci…
Coronal Transverse Magnetohydrodynamic Waves in a Solar Prominence
Lites, B. W.; Ichimoto, K.; Shibata, K. +10 more
Solar prominences are cool 104 kelvin plasma clouds supported in the surrounding 106 kelvin coronal plasma by as-yet-undetermined mechanisms. Observations from Hinode show fine-scale threadlike structures oscillating in the plane of the sky with periods of several minutes. We suggest that these represent Alfvén waves propagat…
Continuous Plasma Outflows from the Edge of a Solar Active Region as a Possible Source of Solar Wind
Golub, Leon; DeLuca, Edward E.; Harra, Louise K. +18 more
The Sun continuously expels a huge amount of ionized material into interplanetary space as the solar wind. Despite its influence on the heliospheric environment, the origin of the solar wind has yet to be well identified. In this paper, we report Hinode X-ray Telescope observations of a solar active region. At the edge of the active region, locate…
Small-Scale Jetlike Features in Penumbral Chromospheres
Lites, B. W.; Ichimoto, K.; Tsuneta, S. +8 more
We observed fine-scale jetlike features, referred to as penumbral microjets, in chromospheres of sunspot penumbrae. The microjets were identified in image sequences of a sunspot taken through a Ca II H-line filter on the Solar Optical Telescope on board the Japanese solar physics satellite Hinode. The microjets’ small width of 400 kilometers and s…
Slipping Magnetic Reconnection in Coronal Loops
Golub, Leon; DeLuca, Edward E.; Narukage, Noriyuki +6 more
Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep …
Twisting Motions of Sunspot Penumbral Filaments
Kubo, M.; Lites, B. W.; Ichimoto, K. +8 more
The penumbra of a sunspot is composed of numerous thin, radially extended, bright and dark filaments carrying outward gas flows (the Evershed flow). Using high-resolution images obtained by the Solar Optical Telescope aboard the solar physics satellite Hinode, we discovered a number of penumbral bright filaments revealing twisting motions about th…
Fine Thermal Structure of a Coronal Active Region
Golub, Leon; Reale, Fabio; Shimojo, Masumi +9 more
The determination of the fine thermal structure of the solar corona is fundamental to constraining the coronal heating mechanisms. The Hinode X-ray Telescope collected images of the solar corona in different passbands, thus providing temperature diagnostics through energy ratios. By combining different filters to optimize the signal-to-noise ratio…