PSRD: Chondrules: Important, but Possibly Unfathomable
... largest are only a couple of centimeters across)? Do the sizes reflect their formation conditions or subsequent sorting? http://www.psrd.hawaii.edu/April17/chondrules.html ...
... largest are only a couple of centimeters across)? Do the sizes reflect their formation conditions or subsequent sorting? http://www.psrd.hawaii.edu/April17/chondrules.html ...
- Repository of the Academy`s Library
... species (e.g. electrons and positive ions), plasma temperature and gas pressure. In addition, MHD waves include perturbations of the electric field, electric current, and macroscopic (or bulk) flows of the plasma. Essentially, the presence of MHD waves is connected with MHD restoring forces associat ...
... species (e.g. electrons and positive ions), plasma temperature and gas pressure. In addition, MHD waves include perturbations of the electric field, electric current, and macroscopic (or bulk) flows of the plasma. Essentially, the presence of MHD waves is connected with MHD restoring forces associat ...
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... This finding enabled us to follow the history of energy release and acquire further information which is important for the studies of particle acceleration in flares in the following Chapters. In Chapter 3 we present the relationship between the spatial distribution of Hα kernels and the distributio ...
... This finding enabled us to follow the history of energy release and acquire further information which is important for the studies of particle acceleration in flares in the following Chapters. In Chapter 3 we present the relationship between the spatial distribution of Hα kernels and the distributio ...
The Plasma Physics Processes that Drive Ring Current
... and reacting to the constant and ever-changing electric and magnetic fields that fill the voids of space. ...
... and reacting to the constant and ever-changing electric and magnetic fields that fill the voids of space. ...
Plasma Diagnostics and Hydrodynamic Evolution of Solar Flares
... 193 Å (right). Images courtesy of helioviewer.org . . . . . . . . . . . . . . ...
... 193 Å (right). Images courtesy of helioviewer.org . . . . . . . . . . . . . . ...
Solar Flares: Magnetohydrodynamic Processes | SpringerLink
... such as radiative energy, kinetic bulk energy, thermal and nonthermal energy. Because of their magnificent behavior, flares have been one of the most attractive scientific targets of the solar physics since they were first observed in the 19th century. The spatial size of a flare depends on individu ...
... such as radiative energy, kinetic bulk energy, thermal and nonthermal energy. Because of their magnificent behavior, flares have been one of the most attractive scientific targets of the solar physics since they were first observed in the 19th century. The spatial size of a flare depends on individu ...
Plasmoid-induced-reconnection and fractal reconnection Kazunari Shibata and Syuniti Tanuma
... al., 1997), and Yohkoh has shown that giant arcades formed after prominence eruptions or CMEs are physically similar to flare arcades even though their total X-ray intensity is much lower than that of normal flares (e.g., Tsuneta et al., 1992b; Hanaoka et al., 1994). Figure 2 shows several examples ...
... al., 1997), and Yohkoh has shown that giant arcades formed after prominence eruptions or CMEs are physically similar to flare arcades even though their total X-ray intensity is much lower than that of normal flares (e.g., Tsuneta et al., 1992b; Hanaoka et al., 1994). Figure 2 shows several examples ...
Flare Observations
... Since September 1, 1859, when R.C. Carrington and R. Hodgson observed the first flare in the continuum of white light, the localized, minute-long brightenings on the Sun have remained an enigma. Local flaring of the Sun has been reported at all wavelengths accessible from the ground and from space. ...
... Since September 1, 1859, when R.C. Carrington and R. Hodgson observed the first flare in the continuum of white light, the localized, minute-long brightenings on the Sun have remained an enigma. Local flaring of the Sun has been reported at all wavelengths accessible from the ground and from space. ...
SOLAR HARD X-RAY AND GAMMA-RAY OBSERVATIONS FROM
... ,SMM(see, e.g., Chupp 1990a; Rieger 1990 for reviews), Hinotori (Yoshimori 1989), and more recently COMPTON (Murphyetal. 1993)and rO/Z/iTOtf (Yoshimorietal. 1992). A typical gamma-ray spectrum consists of several prompt nuclear de-excitation lines from elements of the solar atmosphere (e.g., Fe, Mg, ...
... ,SMM(see, e.g., Chupp 1990a; Rieger 1990 for reviews), Hinotori (Yoshimori 1989), and more recently COMPTON (Murphyetal. 1993)and rO/Z/iTOtf (Yoshimorietal. 1992). A typical gamma-ray spectrum consists of several prompt nuclear de-excitation lines from elements of the solar atmosphere (e.g., Fe, Mg, ...
SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS
... Soft x-ray emissions with brightnesses of about 0.01-0.2 Rayleighs were observed from the equatorial regions of Jupiter using the ROSAT/HRI. It was proposed [40] that the equatorial emission, like the auroral emission, may be largely due to the precipitation of energetic (>300 keV/amu) sulfur or oxy ...
... Soft x-ray emissions with brightnesses of about 0.01-0.2 Rayleighs were observed from the equatorial regions of Jupiter using the ROSAT/HRI. It was proposed [40] that the equatorial emission, like the auroral emission, may be largely due to the precipitation of energetic (>300 keV/amu) sulfur or oxy ...
STELLAR ABLATION OF PLANETARY ATMOSPHERES
... that codes based on this assumption can never include the plasmasphere because its ionospheric origin violates the assumption of a thin shell ionosphere. The plasmasphere is an important region of the inner magnetosphere that was discovered early in the space age [Carpenter, 1963; Carpenter et al., ...
... that codes based on this assumption can never include the plasmasphere because its ionospheric origin violates the assumption of a thin shell ionosphere. The plasmasphere is an important region of the inner magnetosphere that was discovered early in the space age [Carpenter, 1963; Carpenter et al., ...
Master`s Thesis
... satellites respectively. Moreover, the performance on stellar flares detection of an optimal detection algorithm called SISTED (Sunlit Ionosphere Sudden TEC Enhancement Detector[8]), which shares the same physical fundamentals as GSFLAI, is also presented. A total of four stellar flares coming from ...
... satellites respectively. Moreover, the performance on stellar flares detection of an optimal detection algorithm called SISTED (Sunlit Ionosphere Sudden TEC Enhancement Detector[8]), which shares the same physical fundamentals as GSFLAI, is also presented. A total of four stellar flares coming from ...
Exospheres and Atmospheric Escape
... determine the structure of the corona and lead to molecular escape are considered in this paper. A planet’s atmosphere decreases in density with increasing altitude, thus an altitude is eventually reached above which molecules can travel planetary scale distances with a very small probability of mak ...
... determine the structure of the corona and lead to molecular escape are considered in this paper. A planet’s atmosphere decreases in density with increasing altitude, thus an altitude is eventually reached above which molecules can travel planetary scale distances with a very small probability of mak ...
Latitudinal and radial gradients of galactic cosmic ray protons in the
... The orbits of Ulysses and the Earth are known and provide the heliospheric radial (1r) and latitudinal (1θ ) distances between Ulysses and PAMELA. In Fig. 4, Ulysses latitude is shown as a function of radial distance: in red the fast latitude scan of Ulysses going from the southern to the northern h ...
... The orbits of Ulysses and the Earth are known and provide the heliospheric radial (1r) and latitudinal (1θ ) distances between Ulysses and PAMELA. In Fig. 4, Ulysses latitude is shown as a function of radial distance: in red the fast latitude scan of Ulysses going from the southern to the northern h ...
Thermal Convection, Magnetic Field, and Differential Rotation in
... details of the structure are controversial, the tachocline is thought to be ellipsoidal. For example, Charbonneau et al. (1999) show that the center of the tachocline is rt /R⊙ = 0.693 ± 0.003 at the equator which is below the base of the convection zone and rt /R⊙ = 0.717 ± 0.003 at the pole which ...
... details of the structure are controversial, the tachocline is thought to be ellipsoidal. For example, Charbonneau et al. (1999) show that the center of the tachocline is rt /R⊙ = 0.693 ± 0.003 at the equator which is below the base of the convection zone and rt /R⊙ = 0.717 ± 0.003 at the pole which ...
Light perturbation from stellar non radial oscillations: an application
... • Taking into account sphericity of the photosphere reveals a possible significant increase of the relative intensity perturbation at the solar limb for some modes of oscillation: - both for p and g-modes - and only for l+m even modes • The effect on the full-disk perturbation is expected to be smal ...
... • Taking into account sphericity of the photosphere reveals a possible significant increase of the relative intensity perturbation at the solar limb for some modes of oscillation: - both for p and g-modes - and only for l+m even modes • The effect on the full-disk perturbation is expected to be smal ...
cosmic-ray neon, wolf-rayet stars, and the superbubble origin of
... material of solar system composition and accelerated by subsequent SN shocks within the superbubble to provide the bulk of the GCRs. The calculations of Schaller et al. (1992) and Woosley & Weaver (1995) are used to estimate the yields of 20 Ne and 22 Ne from W-R stars and core-collapse SNe, and fro ...
... material of solar system composition and accelerated by subsequent SN shocks within the superbubble to provide the bulk of the GCRs. The calculations of Schaller et al. (1992) and Woosley & Weaver (1995) are used to estimate the yields of 20 Ne and 22 Ne from W-R stars and core-collapse SNe, and fro ...
The magnetic field configuration of a solar prominence inferred from
... structures1 . Prominences, also referred to as filaments when observed against the solar disk, are cool, dense, magnetized formations of 104 K plasma embedded in the 106 K solar corona (for reviews see Mackay et al. 2010; Labrosse et al. 2010). They are located above polarity inversion lines (PILs o ...
... structures1 . Prominences, also referred to as filaments when observed against the solar disk, are cool, dense, magnetized formations of 104 K plasma embedded in the 106 K solar corona (for reviews see Mackay et al. 2010; Labrosse et al. 2010). They are located above polarity inversion lines (PILs o ...
Absence of the strahl during times of slow wind
... et al., 2008; Vocks, 2012; Pavan et al., 2013; Che and Goldstein, 2014; Che et al., 2014); however, there is still no clear consensus on the specific mechanisms involved in the formation of any of its four individual populations. The strahl is thought to be formed from the initial highenergy electro ...
... et al., 2008; Vocks, 2012; Pavan et al., 2013; Che and Goldstein, 2014; Che et al., 2014); however, there is still no clear consensus on the specific mechanisms involved in the formation of any of its four individual populations. The strahl is thought to be formed from the initial highenergy electro ...
Eclipse Box Activity Guide - Girl Scouts of Northern California
... What Is This About? Our Sun shines brightly in the daytime, warms our planet, and helps plants grow. But the sunlight we see with our eyes is only a very small part of the light the Sun gives off. Most sunlight cannot be seen with just our eyes. One type of this invisible light is called “ultraviole ...
... What Is This About? Our Sun shines brightly in the daytime, warms our planet, and helps plants grow. But the sunlight we see with our eyes is only a very small part of the light the Sun gives off. Most sunlight cannot be seen with just our eyes. One type of this invisible light is called “ultraviole ...
EUV and X-ray Spectroscopy of the Active Sun
... path of propagating electrons towards the dense chromosphere (c). Heating of the chromosphere results in chromospheric evaporation (d) which fills the loops with hot, SXR emitting plasma (e). Direct heating of the looptop can result in large pressure gradients that drive conductive fronts (f ). . . ...
... path of propagating electrons towards the dense chromosphere (c). Heating of the chromosphere results in chromospheric evaporation (d) which fills the loops with hot, SXR emitting plasma (e). Direct heating of the looptop can result in large pressure gradients that drive conductive fronts (f ). . . ...
The Sun as an X-Ray Star. III. Flares
... Y ohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar Ñares, for comparison with stellar X-ray Ñares. Eight Ñares, from weak (GOES class C5.8) to very intense ones (X9) are selected as representative of the Ñaring Sun. The emission measure distributio ...
... Y ohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar Ñares, for comparison with stellar X-ray Ñares. Eight Ñares, from weak (GOES class C5.8) to very intense ones (X9) are selected as representative of the Ñaring Sun. The emission measure distributio ...
Infrared Solar Physics - National Optical Astronomy Observatory
... “Why does anyone still observe the Sun using visible wavelengths of light?” a colleague recently asked of me. Certainly night-time astronomers have been exploiting the infrared spectrum for many years to address critical science questions in that field. The spatial resolution, flux and background pr ...
... “Why does anyone still observe the Sun using visible wavelengths of light?” a colleague recently asked of me. Certainly night-time astronomers have been exploiting the infrared spectrum for many years to address critical science questions in that field. The spatial resolution, flux and background pr ...
Potential for Life on the Terrestrial Planets
... The efficiency of atmospheric erosion of CO2-rich exoplanets, with the size and mass similar to that of the Earth, due to Coronal Mass Ejection (CME)-induced ion pick up within close-in habitable zones of active M-type dwarf stars is investigated. Since Mstars are active at the X-ray and EUV radiati ...
... The efficiency of atmospheric erosion of CO2-rich exoplanets, with the size and mass similar to that of the Earth, due to Coronal Mass Ejection (CME)-induced ion pick up within close-in habitable zones of active M-type dwarf stars is investigated. Since Mstars are active at the X-ray and EUV radiati ...
The Limits of Our Solar System - Lunar and Planetary Institute
... Sun, they are accelerated inward by gravity but pushed outward by the radiation pressure (see review by Fahr, 1974). For H, the radiation pressure and gravity are comparable, so the H is not accelerated inward. Helium is heavier and is accelerated inward. Hydrogen also has a much shorter ionization ...
... Sun, they are accelerated inward by gravity but pushed outward by the radiation pressure (see review by Fahr, 1974). For H, the radiation pressure and gravity are comparable, so the H is not accelerated inward. Helium is heavier and is accelerated inward. Hydrogen also has a much shorter ionization ...
Solar phenomena
Solar phenomena are the natural phenomena occurring within the magnetically heated outer atmospheres in the Sun. These phenomena take many forms, including solar wind, radio wave flux, energy bursts such as solar flares, coronal mass ejection or solar eruptions, coronal heating and sunspots.These phenomena are generated by a helical dynamo near the center of the Sun's mass that generates strong magnetic fields and a chaotic dynamo near the surface that generates smaller magnetic field fluctuations.The sum of all solar fluctuations is referred to as solar variation. The collective effect of all solar variations within the Sun's gravitational field is referred to as space weather. A major weather component is the solar wind, a stream of plasma released from the Sun's upper atmosphere. It is responsible for the aurora, natural light displays in the sky in the Arctic and Antarctic. Space weather disturbances can cause solar storms on Earth, disrupting communications, as well as geomagnetic storms in Earth's magnetosphere and sudden ionospheric disturbances in the ionosphere. Variations in solar intensity also affect Earth's climate. These variations can explain events such as ice ages and the Great Oxygenation Event, while the Sun's future expansion into a red giant will likely end life on Earth.Solar activity and related events have been recorded since the 8th century BCE. Babylonians inscribed and possibly predicted solar eclipses, while the earliest extant report of sunspots dates back to the Chinese Book of Changes, c. 800 BCE. The first extant description of the solar corona was in 968, while the earliest sunspot drawing was in 1128 and a solar prominence was described in 1185 in the Russian Chronicle of Novgorod. The invention of the telescope allowed major advances in understanding, allowing the first detailed observations in the 1600s. Solar spectroscopy began in the 1800s, from which properties of the solar atmosphere could be determined, while the creation of daguerreotypy led to the first solar photographs on 2 April 1845. Photography assisted in the study of solar prominences, granulation and spectroscopy. Early in the 20th century, interest in astrophysics surged in America. A number of new observatories were built with solar telescopes around the world. The 1931 invention of the coronagraph allowed the corona to be studied in full daylight.