... We study the variation of the line width and electron density as a function of height above two coronal holes from forbidden spectral lines of Si VIII. The spectra were obtained with the Solar Ultraviolet Measurements of Emitted Radiation spectrometer flown on the Solar and Heliospheric Observatory spacecraft. ... The electron density shows a decrease from 1.1 10 8 cm -3 to 1.6 10 7 cm -3 over the same distance. ...

Next: The derived luminosity and Up: The galactic population of Previous: The galactic population of . Figure 16: The observed distribution of pulsar dispersion measures. Dotted curve is the total known population, solid curve is the Parkes survey. Figure 17: The observed distribution of pulsar distances above the galactic plane. ... Figure 18: The observed distribution of pulsar flux densities. ...

... Science Users Information > Science and Technical Meetings > Conferences 2010 > The Origin and Fate of the Sun: Evolution of Solar-mass Stars Observed with High Angular Resolution . ... Observing Facilities . ... Observing with ESO Telescopes . ... The goal of this workshop is to review recent results on solar-mass stars obtained with infrared and millimeter interferometers, and to discuss their importance for our understanding of stellar evolution from star formation to stellar end products. ...

The CHIANTI database consists of 4 primary ASCII files for each ion in the database. contains the energy levels in cm^(-1) It includes both experimental data and theoretical values of the levels energies. References: %Observed energy levels (2): Feldman, U., Curdt, W., Landi, E., Wilhelm, K., 2000, ApJ, 544, 508 %Observed energy levels (3,4,5): Sandlin, G.D., Bruekner, G.E., Scherrer, V.E., Tousey, R., 1976, ApJ, 205, L47 %Observed energy levels (6 to 15): Fuhr, J.R., et al., ...

The "ring of fire" seen by satellite cameras around the polar caps (picture below) is probably created by electrons leaking from the tail's plasma sheet, whose magnetic field lines form a somewhat imperfect trap. ... One possible explanation involves the close association between auroral arcs and electric currents which flow along field lines between the ionosphere and distant space ( Birkeland currents ). ... That produces an extra resistance to the flow of current. ...

... Note: Click here a longer, much more comprehensive overview of the polar aurora . ... Magnetic Field . ... Aurora . ... 3b. Fritz Aurora . ... Electrons . ... Typical aurora (Dick Hutchinson ї) . In Alaska, Canada, Norway, Finland or northern Russia, on a clear night, a greenish glow is often seen in the sky, known as the "Northern Lights." ... Auroral light is produced at a height of about 100 km (60 miles) when fast electrons, arriving from space, slam into atoms and molecules of the atmosphere. ...

... Data of obs. ... Reduced (Paper I) . NGC 0023 . VIII.1998 . ... NGC 0132 . ... Reduced . NGC 0157 . ... NGC 0615 . ... NGC 0753 . ... NGC 0945 . ... Bad data (clouds); . NGC 0972 . ... II.1998 . ... NGC 1024 . ... NGC 1058 . ... NGC 1073 . ... NGC 1084 . ... NGC 1134 . ... NGC 1637 . ... NGC 2276 . ... NGC 2608 . ... NGC 2964 . ... NGC 3184 . ... Bad data (low S/N) . NGC 3338 . ... Bad data (IFP failure) . NGC 3344 . ... Reduced (bad data) . ... Back to Project Vortex. ...

... Tonight's Sky . ... Observing . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Do the magnetic fields of the planets affect spacecraft during flybys? ... Yes, a spacecraft that has a net charge will feel an effect due to the Lorentz force while moving through a planet s magnetic field. ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email...

... Galaxies 99 Cosmic background with model of cloudy interstellar medium Yu. ... Figure 1: Averaged spectrum of the cosmic background I f in frequency range 0.25 200 MHz for the Galactic poles. ... First interpretation of the cosmic noise background spectrum at broad band frequency range 0.25 200 MHz with a model of the cloudy interstellar medium ISM is presented here. ... Synthesized background spectra I f for regions of the Galactic poles at the frequency range 0.25 200 MHz is presented in Fig. ...

... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...

... Posts tagged ?BEHR? ... A great advantage of Bayesian analysis, they say, is the ability to propagate the posterior. That is, if we derive a posterior probability distribution