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A coronal hole jet observed with Hinode and the Solar Dynamics Observatory
Young, Peter R.; Muglach, Karin
A small blowout jet was observed at the boundary of the south polar coronal hole on 2011 February 8 at around 21:00 UT. Images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) revealed an expanding loop rising from one footpoint of a compact, bipolar bright point. Magnetograms from the Helioseismic Magnetic…
The solar cycle dependence of the weak internetwork flux
McIntosh, Scott W.; Lites, Bruce W.; Centeno, Rebecca
We examine data from the Hinode Observing Program 79 (the "HOP 79" irradiance program) as observed using the Hinode Solar Optical Telescope Spectro-Polarimeter for systematic changes in the weakest observable magnetic flux during the period 2008-2013. At moderate latitudes we find no evidence for systematic changes as a function of time and solar …
Constraining hot plasma in a non-flaring solar active region with FOXSI hard X-ray observations
Krucker, Säm; Shimojo, Masumi; Ishibashi, Kazunori +6 more
We present new constraints on the high-temperature emission measure of a non-flaring solar active region using observations from the recently flown Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket payload. FOXSI has performed the first focused hard X-ray (HXR) observation of the Sun in its first successful flight on 2012 November 2. Focu…
High-speed photospheric material flow observed at the polarity inversion line of a δ-type sunspot producing an X5.4 flare on 2012 March 7
Shimizu, Toshifumi; Lites, Bruce W.; Bamba, Yumi
Solar flares abruptly release the free energy stored as a non-potential magnetic field in the corona and may be accompanied by eruptions of the coronal plasma. Formation of a non-potential magnetic field and the mechanisms for triggering the onset of flares are still poorly understood. In particular, photospheric dynamics observed near those polar…
Coronal behavior before the large flare onset
Kusano, Kanya; Bamba, Yumi; Imada, Shinsuke
Flares are a major explosive event in our solar system. They are often followed by a coronal mass ejection that has the potential to trigger geomagnetic storms. There are various studies aiming to predict when and where the flares are likely to occur. Most of these studies mainly discuss the photospheric and chromospheric activity before the flare…
Coronal loops above an active region: Observation versus model
Peter, Hardi; Bingert, Sven; Bourdin, Philippe-A.
We conducted a high-resolution numerical simulation of the solar corona above a stable active region. The aim is to test the field line braiding mechanism for a sufficient coronal energy input. We also check the applicability of scaling laws for coronal loop properties like the temperature and density. Our 3D MHD model is driven from below by Hino…
Comparison between Hinode/SOT and SDO/HMI, AIA data for the study of the solar flare trigger process
Kusano, Kanya; Bamba, Yumi; Iida, Yusuke +1 more
Understanding the mechanism that produces solar flares is important not only from the scientific point of view but also for improving space weather predictability. There are numerous observational and computational studies that have attempted to reveal the onset mechanism of solar flares. However, the underlying mechanism of flare onset remains el…
Observations of umbral dots and their physical models
Watanabe, Hiroko
The Hinode satellite opens a new era in sunspot research, because of its high spatial resolution and temporal stability. Fine-scale structures in sunspots, called umbral dots (UDs), have become one of the hottest topics in terms of close observations of magnetoconvection. In this paper, a brief review of the observed properties of UDs is given bas…
Morphological study of penumbral formation
Kitai, Reizaburo; Watanabe, Hiroko; Otsuji, Ken'ichi
Penumbrae are known to be areas of mainly horizontal magnetic field surrounding umbrae of relatively large and mature sunspots. In this paper, we observationally studied the formation of penumbrae in NOAA 10978, where several penumbral formations were observed in G-band images of the Solar Optical Telescope on board Hinode. Thanks to the continuou…
Possible signature of Alfvén wave dissipation in the localized magnetic funnels of the equatorial solar corona
Dwivedi, Bhola N.; Mohan, Anita; Srivastava, Abhishek Kumar
We analyse the Hinode/EIS 2″-spectroscopic scan data containing the spectral line formed at typical inner coronal temperature. The strong Fe XII 195.120 Å line shows the existence of funnel-like expanding flux-tubes which exhibit the signature of blue-/red-shifted plasma motions in the off-limb equatorial corona. These coronal funnels expand in th…