A substantial coronal hole rotated across the face of the sun this past week and is again streaming solar wind towards Earth (Jan. 30 - Feb. 2, 2017). This same coronal hole was facing Earth about a month ago and has rotated into a similar position again (see our Gallery entry for this here: https://sdo.gsfc.nasa.gov/gallery/main/item/769. Coronal holes are areas of open magnetic field from which solar wind particles stream into space. In this wavelength of extreme ultraviolet light it appears as a dark area near the center and lower portion of the sun.
Credit: Solar Dynamics Observatory, NASA.