We investigate the interaction between two filaments and the subsequent filament eruption event observed from different view angles by Hinode, the Solar and Heliospheric Observatory (SOHO), and the Solar Terrestrial Relations Observatory (STEREO). In the event, the two filaments rose high, interacted with each other, and finally were ejected along two different paths. We measure the bulk-flow velocity using spectroscopic data. We find significant outflows at the speed of a few hundreds of km/s during the filament eruption, and also some downflows at a few tens of km/s at the edge of the eruption region in the late stage of the eruption. The erupting material was composed of plasmas with a wide temperature range of 10^4-10^6 K. These results shed light on the filament nature and the coronal dynamics.
In our previous articles (Chertok et al.: 2013, Solar Phys. 282, 175, and 2015, Solar Phys. 290, 627), we presented a preliminary tool for the early diagnostics of the geoeffectiveness of solar eruptions based on the estimate of the total unsigned line-of-sight photospheric magnetic flux in accompanying extreme-ultraviolet arcades and dimmings. This tool was based on the analysis of eruptions observed in 1996-2005 with SOHO/EIT and MDI. Empirical relationships were obtained to estimate the probable importance of upcoming space weather disturbances caused by an eruption, which just occurred, wi…
This Letter reports observations of an event that connects all major classes of solar eruptions: those that erupt fully into the heliosphere versus those that fail and are confined to the Sun, and those that eject new flux into the heliosphere, in the form of a flux rope, versus those that eject only new plasma in the form of a jet. The event originated in a filament channel overlying a circular polarity inversion line (PIL) and occurred on 2013-03-20 during the extended decay phase of the active region designated NOAA 12488/12501. The event was especially well-observed by multiple spacecraft …
We present observations of a B7.9-class flare that occurred on the 24th January, 2015, using the Atmopsheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO), the EUV Imaging Spectrometer (EIS) and the X-Ray Telescope of Hinode. The flare triggers the eruption of a dense cool plasma blob as seen in AIA 171Å,\, which is unable to completely break out and remains confined within a local bundle of active region loops. During this process, transverse oscillations of the threads are observed. The cool plasma is then observed to descend back to the chromosphere along each loop strand. …
Surprisingly Large Doppler Shifts in Hinode EUV Imaging Spectrometer (EIS) Solar Spectra, Resulting from an Inconspicuous Small-scale Jet in EUV Images
Elemental Composition Evolution during the 2024 September 30 Solar Eruption: A Comparison of Hot and Cool Plasma Components with Solar Orbiter/SPICE, Hinode/EIS, and Chandrayaan-2/XSM
Southwest Research Institute（西南研究所）；Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado Boulder（科罗拉多大学博尔德分校安与H.J.斯梅德航空航天工程科学系）；Laboratory for Atmospheric and Space Physics, University of Colorado Boulder（科罗拉多大学博尔德分校大气与空间物理实验室）；University of Alabama in Huntsville（阿拉巴马大学亨茨维尔分校）；NASA Marshall Space Flight Center（美国国家航空航天局马歇尔太空飞行中心）
The observations of post eruption arcades (PEAs) in X-rays and EUV reveal strong localised brightenings at the loop top regions. The origin of these brightenings and their dynamics is not well understood to date. Here, we study the dynamics of PEAs using one-dimensional hydrodynamic modelling with the focus on the the understanding of the formation of localised brightening.Our findings suggest that these brightenings are the result of collisions between the counter-streaming chromospheric evaporation from both the foot points. We further perform forward modelling of the emission observed in si…
Study of the three-dimensional shape and dynamics of coronal loops observed by Hinode/EIS
我们研究了2006年12月3日用日之出的极紫外成像光谱仪（EIS）观测到的NOAA活动区10926中沿选定日冕环的等离子体流动。从强度图像上追踪的环的形状和沿其长度测量的多普勒频移，我们使用一个简单的几何模型计算它们的三维（3D）形状和等离子体流速。对Fe VIII 185 Ang.中可见的环进行该计算，Fe X 184角，Fe XII 195 Ang.，Fe XIII 202 Ang.，和Fe XV 284 Ang.谱线。在大多数情况下，从一个足迹到另一个足迹的流动是单向的，但也有从循环顶部到其足迹的排水运动的情况。我们的研究结果表明，相同的环路可能会显示不同的流动模式时，在不同的谱线观察，这表明一个动态的复杂，而不是一个整体结构。我们还进行了磁外推的线性无力场近似使用SOHO/MDI磁图，旨在对一阶识别的外推磁场线对应的重建的循环。在所有情况下，最佳拟合的外推线都表现出左手扭曲（α < 0），与该区域的主导扭曲一致。
The X1 flare and associated filament eruption occurring in NOAA Active Region 12017 on SOL2014-03-29 has been the source of intense study. In this work, we analyse the results of a series of non linear force free field extrapolations of the pre and post flare period of the flare. In combination with observational data provided by the IRIS, Hinode and SDO missions, we have confirmed the existence of two flux ropes present within the active region prior to flaring. Of these two flux ropes, we find that intriguingly only one erupts during the X1 flare. We propose that the reason for this is due t…
We present here an interesting two-step filament eruption during 14-15 March 2015. The filament was located in NOAA AR 12297 and associated with a halo Coronal Mass Ejection (CME). We use observations from the Atmospheric Imaging Assembly (AIA) and Heliospheric Magnetic Imager (HMI) instruments onboard the Solar Dynamics Observatory (SDO), and from the Solar and Heliospheric Observatory (SOHO) Large Angle and Spectrometric Coronagraph (LASCO). We also use H-alpha data from the Global Oscillation Network Group (GONG) telescope and the Kanzelhoehe Solar Observatory. The filament shows a first st…
The relationship between solar eruption and sunspot rotation has been widely reported, and the underlying mechanism requires to be studied. Here we performed a full 3D MHD simulation of data-constrained approach to study the mechanism of flare eruptions in active region (AR) NOAA 10930, which is characterized by continuous sunspot rotation and homologous eruptions. We reconstructed the potential magnetic field from the magnetogram of Hinode/SOT as the initial condition and drove the MHD system by applying continuous sunspot rotation at the bottom boundary. The key magnetic structure before the…
Formation of Transient Coronal Holes during Eruption of a Quiescent Filament and its Overlying Sigmoid
利用H $α$、He I 10830、EUV和软X射线（SXR）数据，对2006年1月12日发生在太阳盘中心附近的一次暗条爆发进行了观测，该爆发扰动了$\emph{GOES-12}$ SXR成像仪（SXI）观测到的暗条通道上的一个S形通道，导致了该通道的爆发。该事件与太阳和日光层天文台（$\emph{SOHO}$）上的大角度和光谱日冕仪（LASCO）观测到的部分晕日冕物质抛射（CME）有关，并导致形成两个耀斑状条带，爆发后日冕环和两个瞬态日冕洞（TCH），但没有明显记录到与爆发相对应的$\emph{GOES}$或H $α$耀斑。这两个TCHs由相反的磁极性主导，位于喷发的乙状结肠的两端。它们在He I 10830、EUV和SXR观测中显示出相似的位置和形状。在早期喷发阶段，增亮首先出现在两个后续的TCH的位置，这可以清楚地识别在He I 10830，EUV和SXR图像。这一喷发事件可以用磁通量绳模型来解释，而两个TCH很可能是磁通绳的脚。
Multiwavelength observation of a large-scale flux rope eruption above kinked mini-filament
我们分析了2012年4月30日发生在AR NOAA 111465的西临耀斑（C3.9）的多波长观测。SDO/AIA 304、1600射电望远镜和Hinode/SOT H $α$记录的高分辨率图像显示了一个与扭结不稳定性相关的小暗条（上升速度$\sim$ 40 km s $^{-1}$）的激活和暗条南支附近C级耀斑的开始。第一次磁重联发生在暗条的一个足点，导致其南支断裂。花丝显示北支和顶点逆时针方向的解绕运动，未能爆发。磁通绳（仅在热通道中可见，即，AIA 131和94通道和Hinode/SXT）结构在扭结丝上发生第二次磁重联时沿中性线出现。在扭曲的暗条上方形成RHESSI硬X射线源（12-25 keV），同时出现与光球增亮（AIA 1700 <$）相关的131 <$s热环，表明粒子从暗条顶部沿着这些环加速。此外，在171光年的灯丝上方观察到的EUV扰动/波也显示出与磁重联的密切联系。磁通绳慢慢上升（$\sim$ 100 km s $^{-1}$）可能通过在$\sim$ 15-20分钟内与周围剪切磁场重联而产生相当大的扭曲结构，AIA 171和SWAP 174的图像显示了一个冷压缩锋，（或CME锋面环）周围的热通量绳结构。
We examine in greater detail five events previously identified as being sources of strong transient coronal outflows in a solar polar region in Hinode/EUV Imaging Spectrometer (EIS) Doppler data. Although relatively compact or faint and inconspicuous in Hinode/Soft X-ray Telescope (XRT) soft-X-ray (SXR) images and in Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) EUV images, we find that all of these events are consistent with being faint coronal X-ray jets. The evidence for this is that the events result from eruption of minifilaments of projected sizes spanning 5000 -- 1…
A quiescent prominence was observed at north-west limb of the Sun using different channels of Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory (SDO). We report and analyse twisting/swirling motions during and after the prominence eruption. We segregate the observed rotational motions into small and large scale. Small scale rotational motions manifest in the barbs of the prominence while the large scale rotation manifests as the roll motion during the prominence eruption. We noticed that both footpoints of the prominence rotate in the counter-clockwise direction. We propose…
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$α$ ($λ$ 1216 Å) spectroheliograph launched on September 30, 2014. The campaign targeted active region NOAA AR 12172 and was closely coordinated with the Hinode and IRIS missions and several ground-based observatories (NSO/IBIS, SOLIS, and BBSO). A filament eruption accompanied by a low level flaring event (at the GOES C-class le…
We report a detailed analysis of a failed eruption and flare in active region 12018 on 2014 April 3 using multiwavelength observations from SDO/AIA, IRIS, STEREO, and Hinode/SOT. At least four jets were observed to emanate from the cusp of this small active region (large bright point) with a null-point topology during the two hours prior to the slow rise of a filament. During the filament slow rise multiple plasma blobs were seen, most likely formed in a null-point current sheet near the cusp. The subsequent filament eruption, which was outside the IRIS field of view, was accompanied by a flar…
Fine-structure dynamics in solar prominences holds critical clues to understanding their physical nature of significant space-weather implications. We report evidence of rotational motions of horizontal helical threads in two active-region prominences observed by the \emph{Hinode} and/or \emph{IRIS} satellites at high resolution. In the first event, we found transverse motions of brightening threads at speeds up to 55~km~s$^{-1}$ seen in the plane of the sky. Such motions appeared as sinusoidal space--time trajectories with a typical period of $\sim$390~s, which is consistent with plane-of-sky…
A recent study using {\it Hinode} (SOT/FG) data of a sunspot revealed some unusually large penumbral jets that often repeatedly occurred at the same locations in the penumbra, namely at the tail of a penumbral filament or where the tails of multiple penumbral filaments converged. These locations had obvious photospheric mixed-polarity magnetic flux in \NaI\ 5896 Stokes-V images obtained with SOT/FG. Several other recent investigations have found that extreme ultraviolet (EUV)/X-ray coronal jets in quiet Sun regions (QRs), coronal holes (CHs) and near active regions (ARs) have obvious mixed-pol…
Most of the commonly discussed solar coronal jets are of the type consisting of a single spire extending approximately vertically from near the solar surface into the corona. Recent research supports that eruption of a miniature filament (minifilament) drives many such single-spire jets, and concurrently generates a miniflare at the eruption site. A different type of coronal jet, identified in X-ray images during the Yohkoh era, are two-sided-loop jets, which extend from a central excitation location in opposite directions, along low-lying coronal loops more-or-less horizontal to the surface. …
Direct Observations of Magnetic Reconnection Outflow and CME Triggering in a Small Erupting Solar Prominence
我们研究了2014年5月1日01：35 UT发生的一次小日珥喷发，并由太阳动力学天文台（SDO）的界面区成像光谱仪（IRIS）和大气成像组件（AIA）观测到。爆发前和爆发后的图像是由日之上的X射线望远镜（XRT）拍摄的。在爆发前，日珥上方存在一个圆顶状的结构，以日冕雨为分界。随着喷发的进行，我们发现了日珥磁场和上覆磁场重连的证据。在AIA和IRIS中可以看到快速流动，表明重新连接流出。在AIA 171 A通道中，沿一条可能重新连接的磁力线观测到了~300 km s $^{-1}$的天平面流。IRIS探测到与AIA气流一致的、约200 km s $^{-1}$的间歇性快速视线气流。差分排放测量计算表明，加热的快速流动的起源。喷发后的XRT图像显示，热环可能是由于重新配置的磁场在喷发和随后的加热等离子体在这些环路。虽然有证据表明在爆发期间日珥上方的重连，但IRIS的高空间分辨率图像显示了日珥下方的潜在重连地点。对爆发日珥的高度-时间分析表明，日珥的初始上升速度为~0.4 km/s $^{-1}$，随后迅速加速，最终速度为~250 km/s $^{-1}$。在这两个阶段之间的过渡期间，IRIS的亮度表明，爆发的快速部分的爆发触发器可能是一个系绳切割机制，而不是突破机制。
The largest magnetic storm in solar cycle 24 was caused by a fast coronal mass ejection (CME) that was related to a small C9.1 flare that occurred on 15 March 2015 in solar active region (AR) NOAA 12297. The purpose of this study is to understand the onset mechanism of the geo-effective huge solar eruption. We focused on the C2.4 flare that occurred prior to the C9.1 flare of the filament eruption. The magnetic field structure in the AR was complicated: there were several filaments including the one that erupted and caused the CME. We hence carefully investigated the photospheric magnetic fiel…
Stealth coronal mass ejections (CMEs) are eruptions from the Sun that have no obvious low coronal signature. These CMEs are characteristically slower events, but can still be geoeffective and affect space weather at Earth. Therefore, understanding the science underpinning these eruptions will greatly improve our ability to detect and, eventually, forecast them. We present a study of two stealth CMEs analysed using advanced image processing techniques that reveal their faint signatures in observations from the extreme ultraviolet (EUV) imagers onboard the Solar and Heliospheric Observatory (SOH…
We report on the 2017 September 10 ground level enhancement (GLE) event associated with a coronal mass ejection (CME) whose initial acceleration (~9.1km s^-2) and initial speed (~4300 km/s) were among the highest observed in the SOHO era. The GLE event was of low intensity (~4.4% above background) and softer-than-average fluence spectrum. We suggest that poor connectivity (longitudinal and latitudinal) of the source to Earth compounded by the weaker ambient magnetic field contributed to these GLE properties. Events with similar high initial speed either lacked GLE association or had softer flu…
We examine a sampling of 23 polar-coronal-hole jets. We first identified the jets in soft X-ray (SXR) images from the X-ray telescope (XRT) on the Hinode spacecraft, over 2014-2016. During this period, frequently the polar holes were small or largely obscured by foreground coronal haze, often making jets difficult to see. We selected 23 jets among those adequately visible during this period, and examined them further using Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) 171, 193, 211, and 304 Ang images. In SXRs we track the lateral drift of the jet spire relative to the je…
Catalogue and statistics of greater than 100 MeV solar proton events during solar cycles 23-25 from SOHO-ERNE observations
National Observatory of Athens（雅典国家天文台）；University of Turku（图尔库大学）；Institut de Recherche en Astrophysique et Planétologie (IRAP), CNRS, Université de Toulouse（天体物理学与行星学研究所以及法国国家科学研究中心，图卢兹大学）；Christian-Albrechts-Universität zu Kiel（基尔基督教阿尔布雷希特大学）；Leibniz-Institut für Astrophysik Potsdam（波茨坦莱布尼茨天体物理研究所）
We report on the linear relationship between the durations of two types of electromagnetic emissions associated with shocks driven by coronal mass ejections: sustained gamma-ray emission (SGRE) and interplanetary type II radio bursts. The relationship implies that shocks accelerate about 10 keV electrons (for type II bursts) and greater than 300 MeV protons (for SGRE) roughly over the same duration. The SGRE events are from the Large Area Telescope (LAT) on board the Fermi satellite, while the type II bursts are from the Radio and Plasma Wave Experiment (WAVES) on board the Wind spacecraft. He…
Three homologous C-class flares and one last M-class flare were observed by both the Solar Dynamics Observatory (SDO) and the Hinode EUV Imaging Spectrometer (EIS) in the AR 11429 on March 9, 2012. All the recurrent flares occurred within a short interval of time (less than 4 hours), showed very similar plasma morphology and were all confined, until the last one when a large-scale eruption occurred. The C-class flares are characterized by the appearance, at approximatively the same locations, of two bright and compact footpoint sources of $\approx$~3--10~MK evaporating plasma, and a semi-circu…
We investigate in detail the magnetic cause of minifilament eruptions that drive coronal-hole jets. We study 13 random on-disk coronal hole jet eruptions, using high resolution X-ray images from Hinode/XRT, EUV images from SDO/AIA, and magnetograms from SDO/HMI. For all 13 events, we track the evolution of the jet-base region and find that a minifilament of cool (transition-region-temperature) plasma is present prior to each jet eruption. HMI magnetograms show that the minifilaments reside along a magnetic neutral line between majority-polarity and minority-polarity magnetic flux patches. Thes…
We study a quiet-Sun blowout jet which is observed on 2014 May 16 by the instruments on board Solar Dynamics Observatory (SDO). We find the twin CME as jet-like and bubble-like CME simultaneously as observed by LASCO C2 on board Solar and Heliospheric Observatory (SoHO), Solar Terrestrial Relation Observatory (STEREO A and STEREO B/COR2). They are respectively associated with the eruption of the northern and southern sections of the filament. A circular filament is rooted at the internetwork region at the base of the blowout jet. The collective magnetic cancellation is observed by SDO/HMI line…
We investigate the coronal and interplanetary evolution of a coronal mass ejection (CME) launched on 2010 September 4 from a source region linking two active regions (ARs) 11101 and 11103, using extreme ultraviolet imaging, magnetogram, white-light and in situ observations from SDO, STEREO, SOHO, VEX and Wind. A potential-field source-surface model is employed to examine the configuration of the coronal magnetic field surrounding the source region. The graduated cylindrical shell model and a triangulation method are applied to determine the kinematics of the CME in the corona and interplanetar…
We describe the energy budget of a coronal mass ejection (CME) observed on 1999 May 17 with the Ultraviolet Coronagraph Spectrometer (UVCS). We constrain the physical properties of the CME's core material as a function of height along the corona by using the spectra taken by the single-slit coronagraph spectrometer at heliocentric distances of 2.6 and 3.1 solar radii. We use plasma diagnostics from intensity ratios, such as the O VI doublet lines, to determine the velocity, density, temperature, and non-equilibrium ionization states. We find that the CME core's velocity is approximately 250 km…
