X-Ray and Extreme Ultraviolet Emission from Comets
... Astrophysical X-ray emission is generally found to originate from hot collisional plasmas, such as the million-degree gas found in the solar corona (e.g., Foukal, 1990), the 100million-degree gas observed in supernova remnants (e.g., Cioffi, 1990), or the accretion disks around neutron stars and bla ...
... Astrophysical X-ray emission is generally found to originate from hot collisional plasmas, such as the million-degree gas found in the solar corona (e.g., Foukal, 1990), the 100million-degree gas observed in supernova remnants (e.g., Cioffi, 1990), or the accretion disks around neutron stars and bla ...
Astronomy Astrophysics
... rotation axis under which the star is seen. The long-term photometry of the young single star LQ Hya, although not included in the initial project, is also used in the present analysis to enlarge the investigated sample. We determined for LQ Hya three different starspot cycles and an antisolar patte ...
... rotation axis under which the star is seen. The long-term photometry of the young single star LQ Hya, although not included in the initial project, is also used in the present analysis to enlarge the investigated sample. We determined for LQ Hya three different starspot cycles and an antisolar patte ...
The Sun as an X-Ray Star. III. Flares
... and emission measures following expected solar-like trends. The peak temperatures of analyzed stellar Ñares are quite higher, and their emission measures orders of magnitude higher ([50 MK and [1054 cm~3, respectively), than typical solar ones. Deviations from the single temperature description have ...
... and emission measures following expected solar-like trends. The peak temperatures of analyzed stellar Ñares are quite higher, and their emission measures orders of magnitude higher ([50 MK and [1054 cm~3, respectively), than typical solar ones. Deviations from the single temperature description have ...
Relationship between solar wind dynamic pressure and amplitude
... is given by C = kfα, where k is the proportionality constant and f (assumed as unity) is related to the mode of the interaction of the IPS or DC with the magnetosphere. Physically, C means SC amplitude normalized by solar wind dynamic pressure variation. A time-varying external magnetic field indu ...
... is given by C = kfα, where k is the proportionality constant and f (assumed as unity) is related to the mode of the interaction of the IPS or DC with the magnetosphere. Physically, C means SC amplitude normalized by solar wind dynamic pressure variation. A time-varying external magnetic field indu ...
Probability of Solar Flares Turn Out to Form a Coronal Mass
... A new solar cycle of 24th has started since 4 January 2008. It is believed that the 24th solar cycle will be less energetic than the last maximum in 2002 2003. Overall energetic eruptions seem to be less frequent in cycle 24 as shown by the lower number of type II radio bursts, full halo CMEs, and i ...
... A new solar cycle of 24th has started since 4 January 2008. It is believed that the 24th solar cycle will be less energetic than the last maximum in 2002 2003. Overall energetic eruptions seem to be less frequent in cycle 24 as shown by the lower number of type II radio bursts, full halo CMEs, and i ...
MHD seismology as a tool to diagnose the coronae of X
... these Sun-like stars have seed magnetic field generation in their interior, which transport outward to permeate their chromosphere and coronae in leading to the formation of transients (e.g., flares) as well as some form of MHD wave activity (e.g., Pandey & Srivastava 2009) similar to the transients ...
... these Sun-like stars have seed magnetic field generation in their interior, which transport outward to permeate their chromosphere and coronae in leading to the formation of transients (e.g., flares) as well as some form of MHD wave activity (e.g., Pandey & Srivastava 2009) similar to the transients ...
A new view on the solar wind interaction with the Moon | Geoscience
... interacting with a magnetic dipole field above an insulating surface, Howes et al. (2015) investigated the lunar surface charging in the magnetic anomaly regions. They have found that the surface gets charged to larger positive potentials of around +50 V when the dipole moment was perpendicular to t ...
... interacting with a magnetic dipole field above an insulating surface, Howes et al. (2015) investigated the lunar surface charging in the magnetic anomaly regions. They have found that the surface gets charged to larger positive potentials of around +50 V when the dipole moment was perpendicular to t ...
The Sirius Festival
... Song 4: “Flame of Silence”. Man does not live unto himself alone. Cosmic process is based upon benevolence and mutual assistance. Those who function under Divine Law are ever ready to help those who have achieved less and, accordingly, are helped by those who have achieved more. The history of huma ...
... Song 4: “Flame of Silence”. Man does not live unto himself alone. Cosmic process is based upon benevolence and mutual assistance. Those who function under Divine Law are ever ready to help those who have achieved less and, accordingly, are helped by those who have achieved more. The history of huma ...
Oxygen isotopes in circumstellar Al_2O_3 grains from meteorites
... The Al 20 3 grains exhibit a range in 16 0/ 18 0 that is larger than predicted for a suite of stars with the same starting composition (Fig. 3). The predicted range in 160/ 18 0 does not increase significantly for stars up to ~15M 0 (Dearborn 1992; El Eid 1994; Boothroyd et al. 1994). Thus, a differ ...
... The Al 20 3 grains exhibit a range in 16 0/ 18 0 that is larger than predicted for a suite of stars with the same starting composition (Fig. 3). The predicted range in 160/ 18 0 does not increase significantly for stars up to ~15M 0 (Dearborn 1992; El Eid 1994; Boothroyd et al. 1994). Thus, a differ ...
The Absolute Chronology and Thermal Processing of Solids in the
... chondrules and, instead, indicate that chondrule formation started contemporaneously with CAIs and lasted ~3 My. This time scale is similar to disk lifetimes inferred from astronomical observations, suggesting that the formation of CAIs and chondrules reflects a process intrinsically linked to the s ...
... chondrules and, instead, indicate that chondrule formation started contemporaneously with CAIs and lasted ~3 My. This time scale is similar to disk lifetimes inferred from astronomical observations, suggesting that the formation of CAIs and chondrules reflects a process intrinsically linked to the s ...
The solar silicon abundance based on 3D non
... abundance determinations, and particularly for the Sun. Unfortunately, errors can enter spectroscopic abundance analyses from a number of different places. Often, errors in the transition probabilities of the spectral lines used to carry out the abundance analysis have a large effect. This is an iss ...
... abundance determinations, and particularly for the Sun. Unfortunately, errors can enter spectroscopic abundance analyses from a number of different places. Often, errors in the transition probabilities of the spectral lines used to carry out the abundance analysis have a large effect. This is an iss ...
Penumbral thermal structure below the visible surface
... We have found that both on average and in 98.7 % of the studied penumbral area, ξ(T ) > 0, which implies that the temperature gradient below the visible surface of the penumbra is lower than the mean temperature gradient of the quiet Sun. A particular interpretation that can be drawn from these resu ...
... We have found that both on average and in 98.7 % of the studied penumbral area, ξ(T ) > 0, which implies that the temperature gradient below the visible surface of the penumbra is lower than the mean temperature gradient of the quiet Sun. A particular interpretation that can be drawn from these resu ...
From the Sun`s atmosphere to the Earth`s atmosphere
... and coronal mass ejections (CMEs) – result from the presence of a dominant magnetic field. Eruptive events correspond to a liberation of magnetic energy stored in the solar corona. This energy is then converted into: – heating of the environment associated with UV/EUV and X beams; – particle acceler ...
... and coronal mass ejections (CMEs) – result from the presence of a dominant magnetic field. Eruptive events correspond to a liberation of magnetic energy stored in the solar corona. This energy is then converted into: – heating of the environment associated with UV/EUV and X beams; – particle acceler ...
seismic constraints on interior solar convection
... bars are identical for both components, but for more clarity these are only shown for the longitudinal velocity. The average level of the travel-time noise in single day MDI medium- quiet Sun data is converted to velocity using the calibration curve in Figure 4. Based on the non-detection of convec ...
... bars are identical for both components, but for more clarity these are only shown for the longitudinal velocity. The average level of the travel-time noise in single day MDI medium- quiet Sun data is converted to velocity using the calibration curve in Figure 4. Based on the non-detection of convec ...
Solar flux variation of the electron temperature morning
... rate also build up after sunrise but it has a smaller effect on the electron temperature than the plasma density. The high temperatures are not seen in the evening during sunset because the electron density has not had time to decay from the high daytime values. [5] A variation of the equatorial mor ...
... rate also build up after sunrise but it has a smaller effect on the electron temperature than the plasma density. The high temperatures are not seen in the evening during sunset because the electron density has not had time to decay from the high daytime values. [5] A variation of the equatorial mor ...
Infrared Solar Physics - National Optical Astronomy Observatory
... many years to address critical science questions in that field. The spatial resolution, flux and background problems are even more extreme at night than they are for observations of the Sun. Infrared detector and instrument technology is clearly robust, and the scientific advantages are important. S ...
... many years to address critical science questions in that field. The spatial resolution, flux and background problems are even more extreme at night than they are for observations of the Sun. Infrared detector and instrument technology is clearly robust, and the scientific advantages are important. S ...
Study of Low Voltage Prebreakdown Sites in Multicrystalline Si
... are not continuous lines but instead consist, as in [11], of bright point sets. Moreover, not all electrically active grain boundaries introduce breakdown sites. It should be noted that, in the EBIC images of grain boundary producing the line breakdown sites (Figure 3(a)), some dark points and lines ...
... are not continuous lines but instead consist, as in [11], of bright point sets. Moreover, not all electrically active grain boundaries introduce breakdown sites. It should be noted that, in the EBIC images of grain boundary producing the line breakdown sites (Figure 3(a)), some dark points and lines ...
Sunspots: from small-scale inhomogeneities towards a global theory
... depth, i.e., along the line-of-sight, and on spatial scales below 0.5 arcsec. Yet, many details of the small-scale geometry of the fields are still unclear such that the small scale inhomogeneities await a consistent explanation. A simple model which relies on magnetic flux tubes evolving in a penum ...
... depth, i.e., along the line-of-sight, and on spatial scales below 0.5 arcsec. Yet, many details of the small-scale geometry of the fields are still unclear such that the small scale inhomogeneities await a consistent explanation. A simple model which relies on magnetic flux tubes evolving in a penum ...
Geomagnetism and Aeronomy, 2016, Vol. 56, № 7, pp. 1
... the solar wind, acceleration of charged particles to high (relativistic) energies and their transport in the heliosphere, triggering of the most powerful phenomena of the solar activity such as flares and coronal mass ejections (CMEs). These and many other problems of solar physics is of general ast ...
... the solar wind, acceleration of charged particles to high (relativistic) energies and their transport in the heliosphere, triggering of the most powerful phenomena of the solar activity such as flares and coronal mass ejections (CMEs). These and many other problems of solar physics is of general ast ...
- Achieve the Core
... region where the Voyagers are now "the heliosheath." It is essentially the border crossing between the Solar System and the rest of the Milky Way. Lots of things try to get across— interstellar clouds, knots of galactic magnetism, cosmic rays and so on. Will these intruders encounter a riot of bubbl ...
... region where the Voyagers are now "the heliosheath." It is essentially the border crossing between the Solar System and the rest of the Milky Way. Lots of things try to get across— interstellar clouds, knots of galactic magnetism, cosmic rays and so on. Will these intruders encounter a riot of bubbl ...
Upper ionosphere of Mars is not axially symmetrical
... Figure 6 compares the maps of the local electron number density measured by MARSIS in the E + and E − hemispheres for solar zenith angles 45◦ ≤ SZA ≤ 90◦ during years 2005–2006 (MGS was lost in November 2006). An asymmetry, if it does exist, is very weak although the statistics are also not sufficie ...
... Figure 6 compares the maps of the local electron number density measured by MARSIS in the E + and E − hemispheres for solar zenith angles 45◦ ≤ SZA ≤ 90◦ during years 2005–2006 (MGS was lost in November 2006). An asymmetry, if it does exist, is very weak although the statistics are also not sufficie ...
galactic cosmic radiation and solar energetic particles
... as the inverse of the solar sunspot number cycle. This is discussed more fully in Section 6.2.2.1. The isotropic flux exposure to galactic cosmic radiation in space at sunspot minimum is - 4 protons cm 2 s' resulting in a yearly integrated exposure of - 1.3 x 108 protons/cm2. The isotropic flux expo ...
... as the inverse of the solar sunspot number cycle. This is discussed more fully in Section 6.2.2.1. The isotropic flux exposure to galactic cosmic radiation in space at sunspot minimum is - 4 protons cm 2 s' resulting in a yearly integrated exposure of - 1.3 x 108 protons/cm2. The isotropic flux expo ...
Mass transport in the heliosphere by energetic neutral atoms
... inner source pickup ions. In addition, the recently identified outer source of pickup ions [Schwadron et al., 2002], particularly important for understanding of the causally related anomalous cosmic rays, further complicates interpretation of the pickup ion measurements and establishing the nature o ...
... inner source pickup ions. In addition, the recently identified outer source of pickup ions [Schwadron et al., 2002], particularly important for understanding of the causally related anomalous cosmic rays, further complicates interpretation of the pickup ion measurements and establishing the nature o ...
Plasma waves above the ion cyclotron frequency in the solar wind: a
... 10−4 Hzfci ) which is thought to be where the energy is finally converted into heat. The evolution of the first part of the
diagram (low frequencies) is compatible with the WKB propagation of fluctuations in a spherically expanding solar wind.
...
... 10−4 Hz
Solar observation
Solar observation is the scientific endeavor of studying the Sun and its behavior and relation to the Earth and the remainder of the Solar System. Deliberate solar observation began thousands of years ago. That initial era of direct observation gave way to telescopes in the 1600s followed by satellites in the twentieth century.