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Howard RA, Vourlidas A, Bothmer V, Colaninno RC, DeForest CE, Gallagher B, Hall JR, Hess P, Higginson AK, Korendyke CM, Kouloumvakos A, Lamy PL, Liewer PC, Linker J, Linton M, Penteado P, Plunkett SP, Poirier N, Raouafi NE, Rich N, Rochus P, Rouillard AP, Socker DG, Stenborg G, Thernisien AF, Viall NM. Near-Sun observations of an F-corona decrease and K-corona fine structure. Nature 2019; 576:232-236. [PMID: 31802002 DOI: 10.1038/s41586-019-1807-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 11/08/2019] [Indexed: 11/09/2022]
Abstract
Remote observations of the solar photospheric light scattered by electrons (the K-corona) and dust (the F-corona or zodiacal light) have been made from the ground during eclipses1 and from space at distances as small as 0.3 astronomical units2-5 to the Sun. Previous observations6-8 of dust scattering have not confirmed the existence of the theoretically predicted dust-free zone near the Sun9-11. The transient nature of the corona has been well characterized for large events, but questions still remain (for example, about the initiation of the corona12 and the production of solar energetic particles13) and for small events even its structure is uncertain14. Here we report imaging of the solar corona15 during the first two perihelion passes (0.16-0.25 astronomical units) of the Parker Solar Probe spacecraft13, each lasting ten days. The view from these distances is qualitatively similar to the historical views from ground and space, but there are some notable differences. At short elongations, we observe a decrease in the intensity of the F-coronal intensity, which is suggestive of the long-sought dust free zone9-11. We also resolve the fine-scale plasma structure of very small eruptions, which are frequently ejected from the Sun. These take two forms: the frequently observed magnetic flux ropes12,16 and the predicted, but not yet observed, magnetic islands17,18 arising from the tearing-mode instability in the current sheet. Our observations of the coronal streamer evolution confirm the large-scale topology of the solar corona, but also reveal that, as recently predicted19, streamers are composed of yet smaller substreamers channelling continual density fluctuations at all visible scales.
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Affiliation(s)
- R A Howard
- US Naval Research Laboratory, Washington, DC, USA.
| | - A Vourlidas
- Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, USA
| | - V Bothmer
- Institut für Astrophysik, University of Göttingen, Göttingen, Germany
| | | | | | - B Gallagher
- US Naval Research Laboratory, Washington, DC, USA
| | - J R Hall
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - P Hess
- US Naval Research Laboratory, Washington, DC, USA
| | - A K Higginson
- Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, USA
| | | | - A Kouloumvakos
- L'Institut de Recherche en Astrophysique et Planétologie, Toulouse, France
| | - P L Lamy
- Laboratoire Atmosphères, Milieux et Observations Spatiales, CNRS and UVSQY, Guyancourt, France
| | - P C Liewer
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - J Linker
- Predictive Science Inc, San Diego, CA, USA
| | - M Linton
- US Naval Research Laboratory, Washington, DC, USA
| | - P Penteado
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - S P Plunkett
- National Aeronautics and Space Administration, Washington, DC, USA
| | - N Poirier
- L'Institut de Recherche en Astrophysique et Planétologie, Toulouse, France
| | - N E Raouafi
- Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, USA
| | - N Rich
- US Naval Research Laboratory, Washington, DC, USA
| | - P Rochus
- University of Liège, Liège, Belgium
| | - A P Rouillard
- L'Institut de Recherche en Astrophysique et Planétologie, Toulouse, France
| | - D G Socker
- US Naval Research Laboratory, Washington, DC, USA
| | - G Stenborg
- US Naval Research Laboratory, Washington, DC, USA
| | | | - N M Viall
- Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD, USA
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