G. Stenborg's research while affiliated with Johns Hopkins University and other places

Publications (160)

Article
Full-text available
Although coronal mass ejections (CMEs) resembling flux ropes generally expand self-similarly, deformations along their fronts have been reported in observations and simulations. We present evidence of one CME becoming deformed after a period of self-similar expansion in the corona. The event was observed by multiple white-light imagers on 2021 Janu...
Article
Full-text available
The Wide-field Imager for Solar Probe (WISPR) onboard Parker Solar Probe (PSP), observing in white light, has a fixed angular field of view, extending from 13.5∘ to 108∘ from the Sun and approximately 50∘ in the transverse direction. In January 2021, on its seventh orbit, PSP crossed the heliospheric current sheet (HCS) near perihelion at a distanc...
Preprint
Full-text available
Although coronal mass ejections (CMEs) resembling flux ropes generally expand self-similarly, deformations along their fronts have been reported in observations and simulations. We present evidence of one CME becoming deformed after a period of self-similarly expansion in the corona. The event was observed by multiple white-light imagers on January...
Preprint
Full-text available
The Wide-field Imager for Solar Probe (WISPR) onboard Parker Solar Probe (PSP), observing in white light, has a fixed angular field of view, extending from 13.5 degree to 108 degree from the Sun and approximately 50 degree in the transverse direction. In January 2021, on its seventh orbit, PSP crossed the heliospheric current sheet (HCS) near perih...
Article
Full-text available
We present an update to the first white-light detections of a dust trail observed closely following the orbit of asteroid (3200) Phaethon, as seen by the Wide-field Imager for the Parker Solar Probe instrument on the NASA Parker Solar Probe mission. Here, we provide a summary and analysis of observations of the dust trail over nine separate mission...
Article
Full-text available
Context. Recurrent, arc-shaped intensity disturbances were detected by extreme-ultraviolet channels in an active region. The fronts were observed to propagate along a coronal loop bundle rooted in a small area within a sunspot umbra. Previous works have linked these intensity disturbances to slow magnetoacoustic waves that propagate from the lower...
Article
Full-text available
The closest perihelion pass of Parker Solar Probe (PSP), so far, occurred between 2021 November 16 and 26 and reached ∼13.29 R ☉ from Sun center. This pass resulted in very unique observations of the solar corona by the Wide-field Instrument for Solar PRobe (WISPR). WISPR observed at least 10 coronal mass ejections (CMEs), some of which were so clo...
Preprint
Full-text available
Recurrent, arc-shaped intensity disturbances were detected by EUV channels in an active region. The fronts were observed to propagate along a coronal loop bundle rooted in a small area within a sunspot umbra. Previous works have linked these intensity disturbances to slow magnetoacoustic waves that propagate from the lower atmosphere to the corona...
Preprint
Full-text available
The closest perihelion pass of Parker Solar Probe (PSP), so far, occurred between 16 and 26 of November 2021 and reached ~13.29 Rsun from Sun center. This pass resulted in very unique observations of the solar corona by the Wide-field Instrument for Solar PRobe (WISPR). WISPR observed at least ten CMEs, some of which were so close that the structur...
Preprint
Full-text available
We present an update to the first white-light detections of a dust trail observed closely following the orbit of asteroid (3200) Phaethon, as seen by the Wide-field Imager for Parker Solar Probe (WISPR) instrument on the NASA Parker Solar Probe (PSP) mission. Here we provide a summary and analysis of observations of the dust trail over nine separat...
Article
We present the fine structure of the inner solar corona between 1.65 and 3.0 solar radii as revealed by the STEREO-A COR1 white-light coronagraph from 2008 June 20 to July 31. The COR1 imaging data were wavelet processed to enhance the intensity contrast of coronal features. The constructed limb synoptic maps at a range of altitudes show the evolut...
Article
We analyze the formation and three-dimensional (3D) evolution of two coronal mass ejections (CMEs) and their associated waves in the low corona via a detailed multi-viewpoint analysis of extreme-ultraviolet observations. We analyze the kinematics in the radial and lateral directions and identify three stages in the early evolution of the CME: (1) a...
Article
Visible light observations from the Wide-field Imager for Solar PRobe (WISPR) aboard the Parker Solar Probe (PSP) mission offer a unique opportunity to study the dust environment near the Sun. The existence of a dust-free zone (DFZ) around stars was postulated almost a century ago. Despite numerous attempts to detect it from as close as 0.3 au, obs...
Article
Full-text available
We present images of Venus from the Wide‐Field Imager for Parker Solar Probe (WISPR) telescope on board the Parker Solar Probe (PSP) spacecraft, obtained during PSP's third and fourth flybys of Venus on 2020 July 11 and 2021 February 20, respectively. Thermal emission from the surface is observed on the night side, representing the shortest wavelen...
Article
Full-text available
Hypervelocity impacts on spacecraft surfaces produce a wide range of effects including transient plasma clouds, surface material ablation, and for some impacts, the liberation of spacecraft material as debris clouds. This study examines debris-producing impacts on the Parker Solar Probe spacecraft as it traverses the densest part of the zodiacal cl...
Article
Full-text available
We present the calibration status and data reduction methodology for the Wide Field Imager for Solar Probe (WISPR) on board the Parker Solar Probe (PSP) mission. In particular, we describe the process for converting a raw image, measured in digital numbers (DN), to a calibrated image, measured in mean solar brightness (MSB). We also discuss details...
Article
The Parker Solar Probe mission (PSP) has completed seven orbits around the Sun. The Wide-field Imager for Solar Probe (WISPR) on PSP consists of two visible light heliospheric imagers, which together image the interplanetary medium between 13.°5 and 108° elongation. The PSP/WISPR nominal science observing window occurs during the solar encounters,...
Article
Context. In 1929, Russell predicted that dust particles cannot survive in a region close to any star, hence giving justification for a dust free zone to exist inside a certain distance from the star. This theoretical prediction has not been confirmed, even with our Sun. Aims. We use the unique vantage points and new perspectives of the Parker Solar...
Article
Full-text available
The analysis of the deflection of coronal mass ejection (CME) events plays an important role in the improvement of the forecasting of their geo-effectiveness. Motivated by the scarcity of comprehensive studies of CME events with a focus on the governing conditions that drive deflections during their early stages, we performed an extensive analysis...
Article
Full-text available
The time of arrival (ToA) of coronal mass ejections (CMEs) at Earth is a key parameter due to the space weather phenomena associated with the CME arrival, such as intense geomagnetic storms. Despite the incremental use of new instrumentation and the development of novel methodologies, ToA estimated errors remain above 10 h on average. Here, we inve...
Article
Full-text available
A proper characterization of the kinematics of coronal mass ejections (CMEs) is important not only for practical purposes, i.e. space weather forecasting, but also to improve our current understanding of the physics behind their evolution in the middle corona and into the heliosphere. The first and core step toward this goal is the estimation of th...
Preprint
Full-text available
The analysis of the deflection of coronal mass ejection (CME) events plays an important role in the improvement of the forecasting of their geo-effectiveness. Motivated by the scarcity of comprehensive studies of CME events with focus on the governing conditions that drive deflections during their early stages, we performed an extensive analysis of...
Article
Full-text available
Slow waves are commonly observed on the entire solar atmosphere. Assuming a thin flux tube approximation, the cut-off periods of slow-mode magneto-acoustic-gravity waves that travel from the photosphere to the corona were obtained in Costa et al. In that paper, however, a typo in the specific heat coefficient at constant pressure cp value led to an...
Article
Full-text available
The Wide-field Imager for Parker Solar Probe (WISPR) captures unprecedented white-light images of the solar corona and inner heliosphere. Thanks to the uniqueness of the Parker Solar Probe’s (PSP) orbit, WISPR is able to image “locally” coronal structures at high spatial and time resolutions. The observed plane of sky, however, rapidly changes beca...
Preprint
Slow waves are commonly observed on the entire solar atmosphere. Assuming a thin flux tube approximation, the cut-off periods of slow-mode magneto-acoustic-gravity waves that travel from the photosphere to the corona were obtained in Costa et al. (2018). In that paper, however, a typo in the specific heat coefficient at constant pressure $c_{\mathr...
Preprint
Full-text available
The Wide-field Imager for Parker Solar Probe (WISPR) captures unprecedented white-light images of the solar corona and inner heliosphere. Thanks to the uniqueness of Parker Solar Probe's (PSP) orbit, WISPR is able to image ``locally'' coronal structures at high spatial and time resolutions. The observed plane of sky, however, rapidly changes becaus...
Article
Full-text available
During its first solar encounter, the Parker Solar Probe (PSP) acquired unprecedented up-close imaging of a small Coronal Mass Ejection (CME) propagating in the forming slow solar wind. The CME originated as a cavity imaged in extreme ultraviolet that moved very slowly (<50 km/s) to the 3-5 solar radii (Rsun) where it then accelerated to supersonic...
Preprint
Full-text available
During its first solar encounter, the Parker Solar Probe (PSP) acquired unprecedented up-close imaging of a small Coronal Mass Ejection (CME) propagating in the forming slow solar wind. The CME originated as a cavity imaged in extreme ultraviolet that moved very slowly ($<50$ km/s) to the 3-5 solar radii (R$_\odot$) where it then accelerated to sup...
Preprint
Full-text available
The Time-of-Arrival (ToA) of coronal mass ejections (CME) at Earth is a key parameter due to the space weather phenomena associated with the CME arrival, such as intense geomagnetic storms. Despite the incremental use of new instrumentation and the development of novel methodologies, ToA estimated errors remain above 10 hours on average. Here, we i...
Article
Full-text available
The Wide-field Imager for Solar PRobe (WISPR) obtained the first high-resolution images of coronal rays at heights below 15 Rsun when Parker Solar Probe (PSP) was located inside 0.25 au during the first encounter. We exploit these remarkable images to reveal the structure of coronal rays at scales that are not easily discernible in images taken fro...
Preprint
The Wide-field Imager for Solar PRobe (WISPR) obtained the first high-resolution images of coronal rays at heights below 15 R$_\odot$ when the Parker Solar Probe (PSP) was located inside 0.25 au during the first encounter. We exploit these remarkable images to reveal the structure of coronal rays at scales that are not easily discernible in images...
Article
Full-text available
The physical mechanisms that produce the slow solar wind are still highly debated. Parker Solar Probe's (PSP's) second solar encounter provided a new opportunity to relate in situ measurements of the nascent slow solar wind with white-light images of streamer flows. We exploit data taken by the Solar and Heliospheric Observatory (SOHO), the Solar T...
Preprint
On 2018 November 5, about 24 hours before the first close perihelion passage of Parker Solar Probe (PSP), a coronal mass ejection (CME) entered the field of view of the inner detector of the Wide-field Imager for Solar PRobe (WISPR) instrument onboard PSP, with the northward component of its trajectory carrying the leading edge of the CME off the t...
Preprint
Full-text available
The physical mechanisms that produce the slow solar wind are still highly debated. Parker Solar Probe's (PSP's) second solar encounter provided a new opportunity to relate in situ measurements of the nascent slow solar wind with white-light images of streamer flows. We exploit data taken by the Solar and Heliospheric Observatory (SOHO), the Solar T...
Preprint
Full-text available
We present the identification and preliminary analysis of a dust trail following the orbit of (3200) Phaethon as seen in white light images recorded by the Wide-field Imager for Parker Solar Probe (WISPR) instrument on the NASA Parker Solar Probe (PSP) mission. During PSP's first solar encounter in November 2018, a dust trail following Phaethon's o...
Preprint
Full-text available
The Wide-field Imager for Solar Probe (WISPR) on board the Parker Solar Probe (PSP) observed a CME on 2018 November 01, the first day of the initial PSP encounter. The speed of the CME, approximately 200-300 km s$^{-1}$ in the WISPR field of view, is typical of slow, streamer blowout CMEs. This event was also observed by the LASCO coronagraphs. WIS...
Article
Full-text available
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 theoreti...
Article
Understanding the deflection of coronal mass ejections (CMEs) is of great interest to the space weather community because of their implications for improving the prediction of CME. This paper aims to shed light into the effects of the coronal magnetic field environment on CME trajectories. We analyze the influence of the magnetic environment on the...
Article
To test a technique to be used on the white-light imager onboard the recently launched Parker Solar Probe mission, we performed a numerical differentiation of the brightness profiles along the photometric axis of the F-corona models that are derived from STEREO Ahead Sun Earth Connection Heliospheric Investigation observations recorded with the HI-...
Article
The white-light Fraunhofer-corona (F-corona) arises from light scattered by the circumsolar dust. Using weekly minimum background models of ST-A/HI-1 observations, we characterized the flattening of the F-corona between 5° and 24° elongation by measuring the radii of constant-intensity contours along, and at a 25° angle to, the photometric axis. Th...
Article
We present an analysis of widths and kinematic properties of coronal mass ejections (CMEs) obtained via a supervised image segmentation algorithm, the CORonal SEgmentation Technique (CORSET), on simultaneous observations from the two COR2 telescopes on the Solar Terrestrial Relations Observatory (STEREO) mission, from 2007 May to 2014 September. Th...
Article
The white-light F-corona arises from light scattered by circumsolar dust. Using weekly models of the eastern side of the F-corona between 5° and 24° elongation, we analyzed the elongation and time dependence of the brightness of its photometric axis. The models were constructed from STEREO-A SECCHI/HI-1 images taken between 2007 December and 2014 M...
Article
Full-text available
We have carried out a statistical analysis of the kinematical behavior of small white-light transients (blobs) as tracers of the slow solar wind. The characterization of these faint white-light structures gives us insight on the origin and acceleration of the slow solar wind. The vantage observing points provided by the SECCHI and LASCO instruments...
Article
The white-light STEREO/SECCHI images include light scattered by dust in orbit about the Sun (the F-corona). We analyzed the evolution of the symmetry axis of the F-corona between 2007 and 2012 in the elongation range covered by the STEREO-A/HI-1 instrument (4°–24° elongation) to characterize the plane of symmetry of the zodiacal dust cloud. The sym...
Article
Full-text available
Coronal mass ejection (CME) events are among the main drivers of geomagnetic disturbances, and hence play a central role in the Sun–Earth system. Their monitoring and, in particular, the determination of their speed and direction of propagation are key issues for the forecasting of space weather near to Earth. We have implemented a method to track...
Article
We present the analysis of an unusual failed eruption captured in high cadence and in many wavelengths during the observing campaign in support of the VAULT2.0 sounding rocket launch. The refurbished Very high Angular resolution Ultraviolet Telescope (VAULT2.0) is a Ly$\alpha$ ($\lambda$ 1216 \AA) spectroheliograph launched on September 30, 2014. T...
Article
White-light coronal and heliospheric imagers observe scattering of photospheric light from both dust particles (the F-Corona) and free electrons in the corona (the K-corona). The separation of the two coronae is thus vitally important to reveal the faint K-coronal structures (e.g., streamers, co-rotating interaction regions, coronal mass ejections,...
Article
We present the first multi-viewpoint coronal mass ejection (CME) catalog. The events are identified visually in simultaneous total brightness observations from the twin SECCHI/COR2 coronagraphs on board the Solar Terrestrial Relations Observatory mission. The Multi-View CME Catalog differs from past catalogs in three key aspects: (1) all events bet...
Article
Full-text available
In spite of the wealth of imaging observations at extreme–ultraviolet, X–ray, and radio wavelengths, there are still a relatively small number of cases where the whole imagery becomes available to study the full development of a coronal mass ejection (CME) event and its associated shock. The aim of this study is to contribute to the understanding o...
Article
Very high angular resolution ultraviolet telescope (VAULT2.0) is a Lyman-alpha (Lyα; 1216Å) spectroheliograph designed to observe the upper chromospheric region of the solar atmosphere with high spatial (<0.5′′) and temporal (8s) resolution. Besides being the brightest line in the solar spectrum, Lyα emission arises at the temperature interface bet...
Article
High-quality white-light images from the SECCHI/HI-1 telescope onboard STEREO-B reveal high-velocity evanescent clumps [HVECs] expelled from the coma of the C/2011 L4 [Pan-STARRS] comet. Animated images provide evidence of highly dynamic ejecta moving near-radially in the anti-sunward direction. The bulk speed of the clumps at their initial detecti...
Conference Paper
Full-text available
To contribute to the understanding of the physical mechanisms at work during the initial phase and early evolution of erupting prominences, we analyze combined observations from ground-based and space-borne instruments. We present two case studies, which occurred at two different phases of the solar cycle, namely on March 2, 2002 and on April 16, 2...
Article
We report on the role of small-scale, transient magnetic activity in the formation and evolution of solar coronal plumes. Three plumes within equatorial coronal holes are analyzed over the span of several days based on the Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly 171 Å and 193 Å images and SDO/Helioseismic and Magnetic Imager li...
Article
Full-text available
Coronal mass ejections (CMEs) are the main driver of Space Weather. Therefore, a precise forecasting of their likely geo-effectiveness relies on an accurate tracking of their morphological and kinematical evolution throughout the interplanetary medium. However, single view-point observations require many assumptions to model the development of the...
Article
Employing Fe XII images and line-of-sight magnetograms, we deduce the direction of the axial field in high-latitude filament channels from the orientation of the adjacent stalklike structures. Throughout the rising phase of the current solar cycle 24, filament channels poleward of latitude 30° overwhelmingly obeyed the hemispheric chirality rule, b...
Article
The white light coronagraphs onboard SOHO (LASCO-C2 and -C3) and most recently STEREO (SECCHI -COR1 and -COR2) have detected a myriad of coronal mass ejections (CME). They are a key component of space weather and under certain conditions they can become geo-effective, hence the importance of their kinematic characterization to help predict their ef...
Article
Full-text available
Magnetic flux ropes play a central role in the physics of Coronal Mass Ejections (CMEs). Although a flux rope topology is inferred for the majority of coronagraphic observations of CMEs, a heated debate rages on whether the flux ropes pre-exist or whether they are formed on-the-fly during the eruption. Here, we present a detailed analysis of Extrem...
Article
During 2 – 18 January 2008 a pair of low-latitude opposite-polarity coronal holes (CHs) were observed on the Sun with two active regions (ARs) and the heliospheric plasma sheet located between them. We use the Hinode/EUV Imaging Spectrometer (EIS) to locate AR-related outflows and measure their velocities. Solar-Terrestrial Relations Observatory (S...
Article
During 2-18 January 2008 a pair of low-latitude opposite polarity coronal holes were observed on the Sun flanked by two ARs with the heliospheric plasma sheet between them. Hinode/EUV Imaging Telescope (EIS) is used to locate AR-related outflows and measure their velocities. The Advanced Composition Explorer (ACE) in-situ observations are employed...
Article
We present results of an ongoing observational study of the main properties of polar coronal jets and how they interact with the surrounding corona. While magnetic reconnection is considered the prime driving mechanism of the ejected plasma, the processes at work during reconnection are not yet completely understood. We use multi-instrument measure...
Article
Full-text available
Observations of the early rise and propagation phases of solar eruptive prominences can provide clues about the forces acting on them through the behavior of their acceleration with height. We have analyzed such an event, observed on 13 April 2010 by SWAP on PROBA2 and EUVI on STEREO. A feature at the top of the erupting prominence was identified a...
Article
Plasma outflow velocities within polar coronal plumes and their contribution to the fast solar wind are a matter of controversy. We investigate the plasma dynamics within plumes through the analysis of high cadence and spatial resolution observations from the Solar Dynamic Observatory (SDO) jointly with STEREO and Hinode data. This analysis allows...