Predicting Sky Dome Appearance on Earth
... significantly shift towards the blue anymore beyond this point. Figures 5, 6 and 7 show the obtained results for low and high solar elevations. Two aspects of these results are noteworthy, since they were not expected: 1. As it turns out, sunsets and sunrises on Earth-like exoplanets are still disti ...
... significantly shift towards the blue anymore beyond this point. Figures 5, 6 and 7 show the obtained results for low and high solar elevations. Two aspects of these results are noteworthy, since they were not expected: 1. As it turns out, sunsets and sunrises on Earth-like exoplanets are still disti ...
Slides - GSI Indico
... What is an electron-positron plasma? Strong electric or magnetic fields, high temperatures massive pair production (E > 2mec2 = 1.022 MeV) electron-positron plasma Examples: • Supernovae: Tmax = 3 x 1011 K kT = 30 MeV >> 2mec2 • Magnetars: Neutron Stars with strong magnetic fields B > 1014 G • ...
... What is an electron-positron plasma? Strong electric or magnetic fields, high temperatures massive pair production (E > 2mec2 = 1.022 MeV) electron-positron plasma Examples: • Supernovae: Tmax = 3 x 1011 K kT = 30 MeV >> 2mec2 • Magnetars: Neutron Stars with strong magnetic fields B > 1014 G • ...
Document
... (see next transparency) • The photosphere is thus representative of the originary solar material, since there was not enough time to mix it with the inner part of the sun, where nuclear reactions occurs and element abundances change. ...
... (see next transparency) • The photosphere is thus representative of the originary solar material, since there was not enough time to mix it with the inner part of the sun, where nuclear reactions occurs and element abundances change. ...
1 Pc2 EMIC waves generated high off the equator in the dayside 2
... location in the magnetosphere was also identified and confirmed using the CIS hot ion data (not shown here). [8] Figure 2, first to third panels, shows dynamic spectra from the Cluster 1 FGM instrument for the radial, azimuthal and compressional components respectively. Waves in the Pc2 range are cl ...
... location in the magnetosphere was also identified and confirmed using the CIS hot ion data (not shown here). [8] Figure 2, first to third panels, shows dynamic spectra from the Cluster 1 FGM instrument for the radial, azimuthal and compressional components respectively. Waves in the Pc2 range are cl ...
Solar-type dynamo behaviour in fully convective stars without a
... In solar-type stars (with radiative cores and convective envelopes), the magnetic field powers star spots, flares and other solar phenomena, as well as chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The dynamo responsible for generating the field depends on the shearing of i ...
... In solar-type stars (with radiative cores and convective envelopes), the magnetic field powers star spots, flares and other solar phenomena, as well as chromospheric and coronal emission at ultraviolet to X-ray wavelengths. The dynamo responsible for generating the field depends on the shearing of i ...
Solar System Formation Reading
... process acts both to confine material to a thin disk (what we now call the eccliptic) as well as causing the orbits of the surviving objects to be regular circles that are spaced apart, so that there are no more collisions. This is illustrated in Figure 8.7. The initial process whereby clumps of sol ...
... process acts both to confine material to a thin disk (what we now call the eccliptic) as well as causing the orbits of the surviving objects to be regular circles that are spaced apart, so that there are no more collisions. This is illustrated in Figure 8.7. The initial process whereby clumps of sol ...
Power Point slides for Reporter Review
... Auroral plasma physics remains a quickly developing field combining aspects of microscropic plasma physics, MHD waves and energy flows, ionospheric structure and chemistry, optical observations, etc. Importance of parallel electric fields has been well established; evolution and structure of the aur ...
... Auroral plasma physics remains a quickly developing field combining aspects of microscropic plasma physics, MHD waves and energy flows, ionospheric structure and chemistry, optical observations, etc. Importance of parallel electric fields has been well established; evolution and structure of the aur ...
ASTRONOMY AND ASTROPHYSICS Properties of solar pores
... and polarimetric observations. There have been numerous attempts to determine the true intensity contrast of pores: Rossbach & Schröter (1970) used an idealized Point Spread Function (PSF) to deconvolve their observations and find values around 0.1 of the photospheric intensity. A first empiric ther ...
... and polarimetric observations. There have been numerous attempts to determine the true intensity contrast of pores: Rossbach & Schröter (1970) used an idealized Point Spread Function (PSF) to deconvolve their observations and find values around 0.1 of the photospheric intensity. A first empiric ther ...
A Novel Forecasting System for Solar Particle Events and Flares
... applying temporal criteria [37], a set of 3680 CME-flare pairs, with a relative timing indicative of a causal relationship, was established. Moreover, the application of spatial criteria [38] led to a sub–sample of 888 CME–flare pairs that fulfilled both criteria (out of which 68 were Xclass, 235 M- ...
... applying temporal criteria [37], a set of 3680 CME-flare pairs, with a relative timing indicative of a causal relationship, was established. Moreover, the application of spatial criteria [38] led to a sub–sample of 888 CME–flare pairs that fulfilled both criteria (out of which 68 were Xclass, 235 M- ...
The Sun
... Usually it is the Earth's Moon that eclipses the Sun. Last June, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun. Eventually the alignment became perfect ...
... Usually it is the Earth's Moon that eclipses the Sun. Last June, most unusually, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun. Eventually the alignment became perfect ...
Penumbral thermal structure below the visible surface
... Context. The thermal structure of the penumbra below its visible surface (i.e., τ5 ≥ 1) has important implications for our present understanding of sunspots and their penumbrae: their brightness and energy transport, mode conversion of magneto-acoustic waves, sunspot seismology, and so forth. Aims. ...
... Context. The thermal structure of the penumbra below its visible surface (i.e., τ5 ≥ 1) has important implications for our present understanding of sunspots and their penumbrae: their brightness and energy transport, mode conversion of magneto-acoustic waves, sunspot seismology, and so forth. Aims. ...
Summary
... forces come into play. This is the case in the generalized Jeans instability. The number of free electrons is less than the number of ions, because some of the electrons are captured by the grains, and are therefore immobilized by the high dust masses. The charge of the dust grain depends on the loc ...
... forces come into play. This is the case in the generalized Jeans instability. The number of free electrons is less than the number of ions, because some of the electrons are captured by the grains, and are therefore immobilized by the high dust masses. The charge of the dust grain depends on the loc ...
Simultaneous observation of the electron acceleration and ion deceleration
... the electrons were often heated and the incident solar wind ions were sometimes slightly decelerated. Figure 2 compares the TOF (Time Of Flight) profile of the three different ion populations: solar wind ions, magnetically reflected ions, and ions backscattered at the lunar surface. Figure 2(c), (d) ...
... the electrons were often heated and the incident solar wind ions were sometimes slightly decelerated. Figure 2 compares the TOF (Time Of Flight) profile of the three different ion populations: solar wind ions, magnetically reflected ions, and ions backscattered at the lunar surface. Figure 2(c), (d) ...
EUV and X-ray Spectroscopy of the Active Sun
... Summary This thesis strives to improve our understanding of solar activity, specifically the behaviour of solar flares and coronal mass ejections. An investigation into the hydrodynamic evolution of a confined solar flare was carried out using RHESSI, CDS, GOES and TRACE. Evidence for pre-flare hea ...
... Summary This thesis strives to improve our understanding of solar activity, specifically the behaviour of solar flares and coronal mass ejections. An investigation into the hydrodynamic evolution of a confined solar flare was carried out using RHESSI, CDS, GOES and TRACE. Evidence for pre-flare hea ...
Twin-Double Layer Structure Producing Tailward Ion
... density from the semi-trapped ions in the very central region of plasma sheet is enough to produce significant repulsive electrostatic Coulomb forces; then two major processes will be probably actuated. First, the portion of ions moving essentially vertically (upward or downward) will be reflected b ...
... density from the semi-trapped ions in the very central region of plasma sheet is enough to produce significant repulsive electrostatic Coulomb forces; then two major processes will be probably actuated. First, the portion of ions moving essentially vertically (upward or downward) will be reflected b ...
Lesson 1 The Sun and Other Stars
... of energy from the Sun’s surface that stretch far out into space. Sometimes this energy disrupts satellites, interfering with TV, radio, and cell phone communication systems. Energy from solar flares also causes displays of different-colored lights in Earth’s upper atmosphere. These lights are calle ...
... of energy from the Sun’s surface that stretch far out into space. Sometimes this energy disrupts satellites, interfering with TV, radio, and cell phone communication systems. Energy from solar flares also causes displays of different-colored lights in Earth’s upper atmosphere. These lights are calle ...
В современной астрофизике одной из наиболее
... Many of these problems were attempted to be solved separately one to each other. In this work the new model of the Sun and origin of the Solar system able to give a joint view on all problems listed above is proposed. Models describing the origin of energy from stars, including the energy of the su ...
... Many of these problems were attempted to be solved separately one to each other. In this work the new model of the Sun and origin of the Solar system able to give a joint view on all problems listed above is proposed. Models describing the origin of energy from stars, including the energy of the su ...
The prominent 1.6-year periodicity in solar motion due to the inner
... The distance of the Sun’s centre due to the inner (terrestrial) planets varies between 101.3 km and 808.2 km (Fig. 3), i.e. the difference is about 700 km. This is more, for example, than the depth of the solar photosphere, which is considered to be about 300–500 km. The distance of the Sun’s centre ...
... The distance of the Sun’s centre due to the inner (terrestrial) planets varies between 101.3 km and 808.2 km (Fig. 3), i.e. the difference is about 700 km. This is more, for example, than the depth of the solar photosphere, which is considered to be about 300–500 km. The distance of the Sun’s centre ...
The Aurora
... Aurora can occure on every planet or moon with a megnetic field and an athmosphere The process of generating auroras is the same throughout the whole solar system even if the configuration, the colours and particularly the rapidly-varying displays, are different from what we see on earth ...
... Aurora can occure on every planet or moon with a megnetic field and an athmosphere The process of generating auroras is the same throughout the whole solar system even if the configuration, the colours and particularly the rapidly-varying displays, are different from what we see on earth ...
Thermal conduction effects on the kink instability in coronal loops
... The initial equilibrium condition is a loop of normalised radius 1, so that the aspect ratio of the initial cylinder is 20, similar to Browning & Van der Linden (2003), Browning et al. (2008) and Hood et al. (2009). Each simulation was run with grid resolutions 1282 × 256 and 2562 × 512. Similar res ...
... The initial equilibrium condition is a loop of normalised radius 1, so that the aspect ratio of the initial cylinder is 20, similar to Browning & Van der Linden (2003), Browning et al. (2008) and Hood et al. (2009). Each simulation was run with grid resolutions 1282 × 256 and 2562 × 512. Similar res ...
18th Cambridge Workshop on Cool Stars, Stellar Systems, and the... Proceedings of Lowell Observatory (9-13 June 2014)
... mass and age. We are however not yet able to completely describe these relations quantitatively under the form of scaling laws. Addressing the topic of spaceweather therefore requires a twofold effort: on the one hand constraining how the properties of dynamo-generated magnetic fields depend on stel ...
... mass and age. We are however not yet able to completely describe these relations quantitatively under the form of scaling laws. Addressing the topic of spaceweather therefore requires a twofold effort: on the one hand constraining how the properties of dynamo-generated magnetic fields depend on stel ...
Electron Firehose instability and acceleration of electrons in solar
... celerated to mean energies of about ∼ 25keV at a rate of about 1036 electrons per second in order to sustain the observed intensity of the hard X-ray bursts. Taking the impulsive phase of a flare to last about 10s and assuming an electron density of about 1010 cm−3 (Moore &Fung 1972; Vaiana & Rosner ...
... celerated to mean energies of about ∼ 25keV at a rate of about 1036 electrons per second in order to sustain the observed intensity of the hard X-ray bursts. Taking the impulsive phase of a flare to last about 10s and assuming an electron density of about 1010 cm−3 (Moore &Fung 1972; Vaiana & Rosner ...
Two-stream instability in collisionless shocks and foreshock
... magnetosonic speed CMS = (VA2 + CS2 ) and the speed of light c. The satellite observations of Solar system shocks, e.g. by the Cluster mission [18–20] and numerous others, have shed considerable light on the shock dynamics. The Solar wind has a typical magnetic field of ≈5 nT and a plasma number den ...
... magnetosonic speed CMS = (VA2 + CS2 ) and the speed of light c. The satellite observations of Solar system shocks, e.g. by the Cluster mission [18–20] and numerous others, have shed considerable light on the shock dynamics. The Solar wind has a typical magnetic field of ≈5 nT and a plasma number den ...
Homework #2 1. There are two ways to estimate the energy carried
... b) Estimate the critical radius Rc (in R ) at which tKH ≈ tf f , i.e, at which KH contraction begins, for a given cloud of mass M (in M ). Assume, as we did in class, that the cloud is fully convective at early times. Show that for R < Rc , the cloud undergoes KH contraction according to your crit ...
... b) Estimate the critical radius Rc (in R ) at which tKH ≈ tf f , i.e, at which KH contraction begins, for a given cloud of mass M (in M ). Assume, as we did in class, that the cloud is fully convective at early times. Show that for R < Rc , the cloud undergoes KH contraction according to your crit ...
Corona
A corona (Latin, 'crown') is an aura of plasma that surrounds the sun and other celestial bodies. The Sun's corona extends millions of kilometres into space and is most easily seen during a total solar eclipse, but it is also observable with a coronagraph. The word ""corona"" is a Latin word meaning ""crown"", from the Ancient Greek κορώνη (korōnē, “garland, wreath”).The high temperature of the Sun's corona gives it unusual spectral features, which led some in the 19th century to suggest that it contained a previously unknown element, ""coronium"". Instead, these spectral features have since been explained by highly ionized iron (Fe-XIV). Bengt Edlén, following the work of Grotrian (1939), first identified the coronal lines in 1940 (observed since 1869) as transitions from low-lying metastable levels of the ground configuration of highly ionised metals (the green Fe-XIV line at 5303 Å, but also the red line Fe-X at 6374 Å). These high stages of ionisation indicate a plasma temperature in excess of 1,000,000 kelvin, much hotter than the surface of the sun.Light from the corona comes from three primary sources, which are called by different names although all of them share the same volume of space. The K-corona (K for kontinuierlich, ""continuous"" in German) is created by sunlight scattering off free electrons; Doppler broadening of the reflected photospheric absorption lines completely obscures them, giving the spectral appearance of a continuum with no absorption lines. The F-corona (F for Fraunhofer) is created by sunlight bouncing off dust particles, and is observable because its light contains the Fraunhofer absorption lines that are seen in raw sunlight; the F-corona extends to very high elongation angles from the Sun, where it is called the zodiacal light. The E-corona (E for emission) is due to spectral emission lines produced by ions that are present in the coronal plasma; it may be observed in broad or forbidden or hot spectral emission lines and is the main source of information about the corona's composition.