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<jats:title>Abstract</jats:title> <jats:p>We develop a magnetohydrodynamical model of Alfvén wave-driven wind in open magnetic flux tubes piercing the stellar surface of red giant branch (RGB) and asymptotic giant branch (AGB) stars, and investigate the physical properties of the winds. The model simulations are carried out along the evolutionary tracks of stars with initial mass in the range of 1.5–3.0 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> and initial metallicity <jats:italic>Z</jats:italic> <jats:sub>ini</jats:sub> = 0.02. Setting the surface magnetic field strength to 1 G, we find that the wind during the evolution of the star can be classified into the following four types: the first is wind with velocity higher than 80 km s<jats:sup>−1</jats:sup> in the RGB and early AGB (E-AGB) phases, the second is wind with outflow velocity less than 10 km s<jats:sup>−1</jats:sup> seen around the tip of the RGB or in the E-AGB phase, the third is the unstable wind in the E-AGB and thermally pulsing AGB (TP-AGB) phases, and the fourth is the stable massive and slow wind with mass-loss rate higher than 10<jats:sup>−7</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> yr<jats:sup>−1</jats:sup> and outflow velocity lower than 20 km s<jats:sup>−1</jats:sup> in the TP-AGB phase. The mass-loss rates in the first and second types of wind are two or three orders of magnitude lower than the values evaluated by an empirical formula. The presence of a massive and slow wind of the fourth type suggests the possibility that the massive outflow observed in TP-AGB stars could be attributed to Alfvén wave-driven wind.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The ribbon of enhanced energetic neutral atom flux, discovered by the <jats:italic>Interstellar Boundary Explorer</jats:italic> (<jats:italic>IBEX</jats:italic>) in 2009, has redefined our understanding of the heliosphere’s interaction with the local interstellar medium (LISM). Yet, its origin continues to be a topic of scientific debate. The ribbon is circular and traces the region where the putative LISM magnetic field (<jats:italic>B</jats:italic> <jats:sub>LISM</jats:sub>) is perpendicular to the radial direction from the Sun. Using nine years of <jats:italic>IBEX</jats:italic>-Hi observations, we investigate the ribbon circularity and location as functions of time and energy. We provide updated locations of the ribbon center at five energy passbands (centered at 0.7, 1.1, 1.7, 2.7, and 4.3 keV) in ecliptic coordinates [longitude, latitude]: [217.°41 ± 0.°95, 44.°36 ± 0.°93], [219.°72 ± 0.°95, 41.°50 ± 0.°87], [220.°51 ± 1.°19, 39.°96 ± 1.°00], [218.°08 ± 1.°66, 38.°44 ± 1.°24], and [214.°68 ± 1.°48, 34.°13 ± 1.°19] respectively. The weighted mean center location over all energies and all years is [218.°33 ± 0.°68, 40.°38 ± 0.°88] and its radius is 74.°81 ± 0.°65. As viewed by <jats:italic>IBEX</jats:italic> at 1 au, we find that (1) the ribbon is stable over time, with distinct centers at each energy; (2) ribbon centers exhibit small temporal variations, likely caused by the solar wind (SW) speed and density variations; and (3) ribbon location in the sky appears to be driven by (i) the inherent alignment of the ribbon centers along the plane connecting the presumed <jats:italic>B</jats:italic> <jats:sub>LISM</jats:sub> and the heliospheric upwind direction, and (ii) the variable SW structure along the heliographic meridian, further emphasizing that the ribbon source is outside the heliosphere.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We study the coronal dimming caused by the fast halo CME (deprojected speed <jats:italic>v</jats:italic> = 1250 km s<jats:sup>−1</jats:sup>) associated with the C3.7 two-ribbon flare on 2012 September 27, using <jats:italic>Hinode</jats:italic>/EIS spectroscopy and <jats:italic>Solar Dynamics Observatory</jats:italic> (<jats:italic>SDO</jats:italic>)/AIA Differential Emission Measure (DEM) analysis. The event reveals bipolar core dimmings encompassed by hook-shaped flare ribbons located at the ends of the flare-related polarity inversion line, and marking the footpoints of the erupting filament. In coronal emission lines of log <jats:italic>T</jats:italic> [K] = 5.8–6.3, distinct double-component spectra indicative of the superposition of a stationary and a fast upflowing plasma component with velocities up to 130 km s<jats:sup>−1</jats:sup> are observed at these regions, which were mapped by the scanning EIS slit close in time to their impulsive dimming onset. The outflowing plasma component is found to be of the same order as and even dominant over the stationary one, with electron densities in the upflowing component of 2 × 10<jats:sup>9</jats:sup> cm<jats:sup>−3</jats:sup> at log <jats:italic>T</jats:italic> [K] = 6.2. The density evolution in core-dimming regions derived from <jats:italic>SDO</jats:italic>/AIA DEM analysis reveals impulsive reductions by 40%–50% within ≲10 minutes and remains at these reduced levels for hours. The mass-loss rate derived from the EIS spectroscopy in the dimming regions is of the same order as the mass increase rate observed in the associated white-light CME (1 × 10<jats:sup>12</jats:sup> g s<jats:sup>−1</jats:sup>), indicating that the CME mass increase in the coronagraphic field of view results from plasma flows from below and not from material piled up ahead of the outward-moving and expanding CME front.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>A global MHD–neutrals–cosmic-rays simulation is conducted to investigate the effects of anomalous cosmic-rays (ACRs) on the large-scale structure of the outer heliosphere. In the model, the cosmic-rays are treated as a massless fluid that only contribute their pressure to the dynamics of the system. The diffusion of cosmic-rays in the interstellar medium is assumed to be much faster than inside the heliosphere, where it depends on the strength of the magnetic field. The results show that the influence of the cosmic-rays on the structure of the outer heliosphere depends on momentum and energy transfer from the solar wind plasma to the ACRs, accomplished through diffusive shock acceleration at the termination shock, and the subsequent loss of ACRs across the heliopause and their rapid escape into the interstellar medium. Under favorable conditions characterized by a large fraction of energy conversion and a high enough diffusion coefficient in the solar wind, the ACRs were found to reduce the width of the heliosheath by up to ∼18 au. Consequently, these results indicate that the effect of cosmic-rays is a potential key factor for the global structure of the outer heliosphere in a computer model that could partially explain the timing of the heliopause encounters of the two <jats:italic>Voyager</jats:italic> probes.</jats:p>