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In the early hours of 2021 April 25, the Solar Probe Cup on board Parker Solar Probe registered the passage of a solar wind structure characterized by a clear and constant He2+/H+ density ratio above 6% during three hours. The He2+ contribution remained present but fainting and intermittent within a twelve-hour window. Solar Orbiter and Parker Solar Probe were in nearly perfect quadrature, allowing for optimal observing configuration in which the material impacting the Parker Solar Probe was in the Solar Orbiter plane of the sky and visible off the limb. In this work, we report the journey of the helium-enriched plasma structure from the Sun to the Parker Solar Probe by combining multi-spacecraft remote-sensing and in situ measurements. We identify an erupting prominence as the likely source, behind the Sun relative to the Earth, but visible to multiple instruments on both the Solar-Terrestrial Relations Observatory-A and Solar Orbiter. The associated CME was also observed by coronagraphs and heliospheric imagers from both spacecrafts before reaching the Parker Solar Probe at 46 R⊙, 8 h after the spacecraft registered a crossing of the heliospheric current sheet. Except for extraordinary helium enhancement, the CME showed ordinary plasma signatures and a complex magnetic field with an overall strength enhancement. The images from the Wide-field Imager for Solar Probe (WISPR) aboard Parker Solar Probe show a structure entering the field of view a few hours before the in situ crossing, followed by repetitive transient structures that may be the result of flying through the CME body. We believe this to be the first example of a CME being imaged by WISPR directly before and during being detected in situ. This study highlights the potential of combining the Parker Solar Probe in situ measurements in the inner heliosphere with simultaneous remote-sensing observations in (near) quadrature from other spacecrafts.

Establishing the Sun-Earth connection requires overcoming the challenges of exploring the data from past and current missions and leveraging tools and models (data mining) to create an efficient system treatment of the Sun and heliosphere. However, solar and heliospheric environment data constitute a vast source of information whose potential is far from being optimally exploited. In the next decade, the solar and heliospheric community will have to manage the increasing amount of information coming from new missions, improve re-analysis of data from past and current missions, and create new data products from the application of new methodologies. This complex task is further complicated by practical challenges such as different datasets and catalogs in different formats that may require different pre-processing and analysis tools, and the need for numerous analysis approaches that are not all fully optimized for large volumes of data. While several ongoing efforts aim at addressing these problems, the available datasets and tools are not always used to their full potential often due to lack of awareness of available resources. In this paper, we summarize the issues raised and goals discussed by members of the community during recent conference sessions focused on data mining for science.

We report on the closest view of a coronal mass ejection (CME) observed by the Parker Solar Probe (PSP)/ Wide-field Imager for Parker Solar PRobe (WISPR) instrument on 2022 September 5, when PSP was traversing from a distance of 15.3 to 13.5 R _⊙ from the Sun. The CME leading edge and an arc-shaped concave-up structure near the core were tracked in the WISPR field of view using the polar coordinate system for the first time. Using the impact distance on the Thomson surface, we measured the average speeds of the CME leading edge and concave-up structure as ≈2500 ± 270 km s ^−1 and ≈400 ± 70 km s ^−1 with a deceleration of ≈20 m s ^−2 for the latter. The use of the plane-of-sky approach yielded an unrealistic speed of more than 3 times this estimate. We also used single viewpoint STEREO/COR-2A images to fit the Graduated Cylindrical Shell (GCS) model to the CME while incorporating the source region location from Extreme-Ultraviolet Imager of Solar Orbiter and estimated a 3D speed of ≈2700 km s ^−1 . We conclude that this CME exhibits the highest speed during the ascending phase of solar cycle 25. This places it in the category of extreme-speed CMEs, which account for only 0.15% of all CMEs listed in the CDAW CME catalog.

We describe a rapid and direct method for regularizing, post facto, the point-spread function (PSF) of a telescope or other imaging instrument across its entire field of view (FOV). Imaging instruments in general blur point sources of light by local convolution with a PSF that varies slowly across the FOV, due to coma, spherical aberration, and similar effects. It is possible to regularize the PSF in post-processing, producing data with a homogeneous “effective PSF” across the entire FOV. In turn, the method enables seamless wide-field astronomical mosaics at higher resolution than would otherwise be achievable, and potentially changes the design trade space for telescopes, lenses, and other optical systems where data uniformity is important. For many kinds of optical aberration, simple and rapid convolution with a locally optimized “transfer PSF” produces extremely uniform imaging properties at low computational cost. PSF regularization does not require access to the instrument that obtained the data, and can be bootstrapped from existing data sets that include starfield images or other means of estimating the PSF across the field.