... Like a last gasp of breath, Sun-like stars puff away their outer layers of gas at the end of their lives. This gas floats away into space and forms beautiful and striking clouds, which are called planetary nebulae (although they have nothing to do with planets). ... Yet, astronomers looking at 100 planetary nebulae in the bulging centre of our Galaxy, the Milky Way have found that most of the bipolar planetary nebulae in this region are acting in the same, strange, way. ...

... We sometimes use the word "nebula" to refer to galaxies, various types of star clusters and various kinds of interstellar dust/gas clouds. ... Early in this century, there was a great debate as to the nature of the nebulae like this one which at that time could not be resolved into individual stars. ... A typical galaxy is 100,000 light-years in diameter. ... M 42 shown) Reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars. ... M 1 shown) . ...

... High-velocity clouds (HVCs) were discovered by Muller, Oort & Raimond (1963) in the 21-cm line emission of neutral, atomic hydrogen. They are gas clouds which are characterised by high radial velocities incompatible with a participation in the rotation of our Galaxy. ... This suggestion was seized by Braun & Burton (1999) who identified 66 compact high-velocity clouds (CHVCs) with positional and kinematic characteristics being compatible with a distribution across the entire Local Group. ...

... self-absorption - the absorption of light shining on an object by a process similar to that which produced the light originally; if a cloud emits less light than it absorbs from other clouds behind it, this net loss of light, termed self-absorption , causes the foreground cloud to appear darker than the background field (the term is from spectroscopy, where small absorption dips sometimes occur in larger emission lines, making the latter look as if it is absorbing part of itself) . ... HISA Main ...

... Files in red?history) . ... Trapped Motion . ... 10a. Particle Drift . ... Fast Particles . ... The fact charged particles circle around field lines was well known to J.J. Thomson when he experimented with electron and ion beams in a magnetic field. ... The notion of adiabatic invariance is tied with the early years of quantum theory. ... By about1910, physicists realized that these patterns indicated changes in the laws of physics as one approached atomic dimensions. ...

Circling around magnetic field lines. ... The ring current . Because positive ions and negative electrons drift in opposite directions (see drawing), that motion will create an electric current that circulates clockwise around the Earth when viewed from north. ... How then can the radiation belt and ring current arise? ... Electric fields are able to push trapped particles earthward, and unlike the purely magnetic motion described earlier, an electric field can also energize them. ...

... A faint, dusty rose of the northern sky, emission nebula IC 410 lies about 12,000 light-years away in the constellation Auriga. ... Cosmic Rays . ... The Comet and the Galaxy . ... During late March and early April 1997, Comet Hale-Bopp passed nearly in front of the Andromeda Galaxy. ... The First Explorer . ... Low clouds are seen in silhouette against the first hints of sunlight, while two famous cosmic clouds, the Clouds of Magellan, also hover in the brightening sky. ... A Cerro Tololo Sky . ...

Using the data obtained with the Spitzer Space Telescope as part of the Surveying the Agents of a Galaxy's Evolution (SAGE) legacy survey, we have studied the variations of the dust composition and abundance across the Large Magellanic Cloud (LMC). ... Using a model and comparing with a reference spectral energy distribution from our Galaxy, we deduce the relative abundance variations of small dust grains across the LMC. ... ADS Citation Query . ... citations vs. year [year,citations] . ...

What happens to a star heavier than five solar masses? ... Stars about ten solar masses probably behave like our five solar mass star until they reach the end of core-helium burning. ... The Crab nebula was formed after a massive explosion ripped a star apart in 1054. ... Today, the glowing outer layers of the star are still rushing away from a tiny star in the centre. ... An incredible explosion rips through the outer layers of the star, releasing colossal amounts of energy in a supernova explosion. ...

... Magnetic fields, subatomic particles, etc., traveling in different directions fill the universe. Do they deflect or otherwise affect one another? If so, isnт??t the information we get from them distorted? ... Neutrino astronomy, which is still in its infancy, is attractive because neutrinos interact so weakly with matter that few of these distorting effects occur. Get instant access to subscriber content on Astronomy.com! ...

Astronotes Armagh Planetarium's Stellar Blog! ... Solar System . Sun . ... Stars . ... Monthly Sky Notes . ... Among the wonders of the sky they shared may have been something we do not have today, a neighbouring star roaming through the outer edge of the Solar System. ... Today Scholzт??s Star is about 20 light years from the Sun in the constellation of Monoceros. ... Seen from our Solar System, Scholzт??s Star barely moves across the across the sky. ... Astronotes . ... Subscribe to Astronotes . ...

... August 28, 1998 . Hydrogen Trifid . ... Explanation: Clouds of glowing hydrogen gas mingle with dark dust lanes in the Trifid Nebula , a star forming region in the constellation Sagittarius. In this and other similar emission nebulae , energetic ultraviolet light from an embedded hot young star strips electrons from the surrounding hydrogen atoms . ... It shows those regions with substantial emission from atomic hydrogen . ... Tomorrow's picture: Star Colors . ... About APOD > . ...

GALAXIES cenA .tiff 40 Bright Radio Galaxy M31.tiff Nikon Andromeda Galaxy (note HII regions in spiral arms) ngc6744.tiff 40 NGC 6744 a face-on spiral clouds_20d.tiff H'blad The Magellanic Clouds our nearest neighbours Lmc_7.tiff Nikon The Large Magellanic Clouds Lmc_zoom.tiff Nikon Detail of previous image smc_7.tiff Nikon The Small Magellanic Clouds smc-zoom.tiff Nikon Detail of previous image 30dor_40_BVR.tiff 40 The 30 Dor ... B [OIII] Halpha trifid.tiff 40" The Trifid Nebula. ...

... The ancient chronical said about the colour rings around the Sun and the Moon, about three suns in the sky, light columns, bright lightning, different "comets" rushing to the Earth, moving among the stars or round the Earth with the sky. All these occurrences may be divided into three categories: one that occur in the near or far space, processes going on in the Earth atmosphere under the influence of cosmic factors and at last the occurrences connected with the Earth atmosphere. ... Rainbow . ...

... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

... In a solar prominence, charged particles stream up from the Sun, spiraling around magnetic field structures poking out of the solar surface, and ultimately fall back along those structures into the Sun. ... As evolution would predict, animals' eyes sense the colors of light emitted most strongly by the Sun. ... The tiny Moon can completely cover the disk of the Sun, blocking most of the emitted visible light, and reveal the Sun's faint outer atmosphere called the corona...a mass of incandescent gas ...

... Posts tagged ?systematic error? ... Thanks to L. Lyons? work discussed in [ArXiv] Particle Physics , I found this paper, titled Systematic Errors describing the concept and statistical inference related to systematic errors in the field of particle physics. ... Continue reading ?systematic errors? Tags: coverage , Heinrich , likelihood , Lyons , nuisance parameter , objective priors , p-value , particle physics , statistical error , subjective priors , systematic error . ... Comment . ...

Gamma-rays from the GC . M.Chernyakova (DIAS), D.Malyshev (DIAS), F.Aharonian (DIAS, MPIK), R.M.Crocker(MPIK), D.I.Jones(MPIK) 1 10°x10° Count and TS maps (>300 GeV) Gamma-rays from the GC 2 TS maps of the GC at different energies 300 MeV ­ 3GeV 3 GeV ­ 30 GeV 30 GeV ­ 300 GeV Gamma-rays from the GC 3 4 Gamma-rays from the GC Lightcurve 5 Gamma-rays from the GC Source spectrum Model X-ray and low-energy emission come from the central object, probably SMBH accretion disk. ...

11 august 2014/Monday: Arriving, Registration . ... The variation of solar flare coronal X-ray source spatial properties. ... Melnikov V.F., Charikov Yu.E., Kudriavtsev I.V. Directivity of X-ray and gamma-ray emission from different parts of flaring magnetic loops. ... E., Melnikov V.F. Angular characteristics of polarization degree of hard X-ray emission from different parts of flaring magnetic loops. ... The thick target model and analytical calculations of the hard X-ray emission from solar flares. ...

Next: Polarization efficiency: size/shape/orientation effects Up: Optical properties of cosmic Previous: The 2175? feature . To model the interstellar polarization one needs to calculate the forward-transmitted radiation for an ensemble of non-spherical aligned dust grains. ... Let non-polarized stellar radiation passes through a dusty cloud with a homogeneous magnetic field. ... The angle between the line of sight and the magnetic field is ( ). ... where the angle is connected with and ( ). ...