... UIT , NASA Explanation: This is the mess that is left when a star explodes. ... In the center of the Crab Nebula lies the powerful Crab pulsar - a spinning neutron star with mass comparable to our Sun but with the diameter of only a small town . ... The Crab still presents mysteries today as the total mass of the nebula and pulsar appears much less than the mass of the original pre-supernova star! ... Publications with keywords: pulsar - Crab Nebula . ... M1: The Crab Nebula from Hubble . ...

... November 22, 1998 . The High Energy Crab Nebula . ... UIT , NASA . ... The Crab Nebula is so energetic that it glows in every kind of light known. ... In the center of the Crab Nebula lies the powerful Crab pulsar - a spinning neutron star with mass comparable to our Sun but with the diameter of only a small town . ... The Crab still presents mysteries today as the total mass of the nebula and pulsar appears much less than the mass of the original pre-supernova star! ... About APOD > . ...

home publications > mercury . SEARCH ASP SITE: Match ALL words Match ANY word . ... Publications of the ASP (PASP) . ... What Is a "Planet"? ... The Sun defined daytime and the stars provided a fixed background of twinkling lights at night. ... The Greeks included the Sun and Moon as planets, along with Mercury, Venus, Mars, Jupiter, and Saturn, because motion against the stars was their defining characteristic of "planet." Both the stars and planets were thought to revolve around Earth. ...

... ESO is building what will be the World's largest optical telescope array, The Very Large Telescope (VLT). The VLT Project organisation is responsible for the design and construction of the Unit Telescopes, including enclosures, optics, adapter-rotators and coating unit. ... Unit Telescopes Overview - This page is outdated, an update is in process. ... Secondary mirror (M2 Unit) - This page is outdated, an update is in process. ... Coating Unit - This page is outdated, an update is in process. ...

... Dark energy is believed to be a component of the Universe whose repulsive gravity is presently accelerating the expansion of the Universe.€а Although it comprises the bulk of the mass-energy of the Universe, its nature is not well understood.€а €аAlbert Einstein originally suggested its existence about 80 years ago. A supernova is the explosive death of a star, which unleashes a burst of light through the cosmos. ... This website is a gift from Nancy Riess . ...

... X-rays are made up of photons that are emitted from stars, or quasars, or supernovae, the sun, or simply: anything that is undergoing a change either in size or temperature or giving out heat. ... in an X-ray binary star system, in which one normal star's orbit is crossed by a neutron star, when the neutron star by means of gravitational pull takes matter from the normal star X-rays form. ... Artists conception of a normal star (HDE 226868) and a black hole taking matter from the normal star. ...

... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Such a model can reproduce much of the observed late-time evolution of the radio flux density and spectral index (though recent results for SNб 1993J (van Dyk et al. 1994) show that the Chevalier model does not adequately describe the early behaviour of radio light curves for this supernova, perhaps due to variations in the mass-loss rate and clumping in the stellar wind, which are not yet accounted for in the model). ...

This all-sky image, constructed from 2 years of observations by NASA's Fermi Gamma-ray Space Telescope, shows how the sky appears at energies greater than 1 billion electron volts (1 GeV). Brighter colors indicate brighter gamma-ray sources. ... A diffuse glow fills the sky and is brightest along the plane of our galaxy (middle). Discrete gamma-ray sources include pulsars and supernova remnants within our galaxy as well as distant galaxies powered by supermassive black holes. ...

XMM-Newton Science Analysis System Page: 1 rgso setcalc November 22, 2004 Abstract Calculate the mean and the standard deviation of the pulse height distribution of RGS diagnostic images. ... This will only be implemented at a later time, if in-orbit experience warrants it. rgso setcalc accepts a list of DIAGNOSTIC datasets (refer to the ODF ICD [1]. For each DIAGNOSTIC dataset rgso setcalc calculates the mean and standard deviation of the pulse height distribution. ...

... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...

... Stars . ... Dark Nebula: The Taurus Molecular Cloud, in the constellation of Taurus (The Bull), lies about 450 light years from Earth. This image is a composite of observations made with submillimetre wavelengths, which reveal the heat glow of the molecular cloud (shown in orange tones) and in visible light to reveal the rich background of stars. Image credit: ESO/APEX (MPIfR/ESO/OSO)/A. Hacar et al./ ... The Orion nebula is a very famous nebula and we know that it is full of stars. ...

... November 5, 1997 . The Milky Way's Gamma-Ray Halo . Credit: D. Dixon ( UCR ), D. Hartmann ( Clemson ), E. Kolaczyk ( U. Chicago ), NASA . Explanation: Our Milky Way galaxy appears to be surrounded by a halo of gamma rays . Gamma rays are the most energetic form of electromagnetic radiation , with more than a hundred thousand times the energy of visible light, but known gamma-ray sources don't account for the diffuse distribution of this high-energy glow. ... About APOD > . ...

Cosmic rays are not the only sign of high energy particles in the distant universe. Additional evidence comes (like most astronomical data) from visible light and other types of electromagnetic waves , e.g. x-rays and radio waves. ... Photons of visible light have about 2 electron volts (ev), while medical x-ray photons may have energies of 50,000 ev and those of gamma rays reach 1,000,000 ev and even more. ... To produce x-rays or gamma rays, electrons must collide with something. ...

... Recherche dans le site : . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Un jet de particules de 37 ann†йes-lumi†иre dans la Car†иne . ... Situ†й †а 23 000 ann†йes-lumi†иre dans la constellation australe de la Car†иne, il est produit par une †йtoile †а neutrons en rotation (un pulsar) fon†зant †а plus 3 millions de km/h dans l'espace interstellaire. ... Etat du ciel . ...

Photon Scattering: Basic Principle of Photon Scattering . Audio Narration is available . No Scattering: Photon Source and Detector . ... For optical photons, scattering goes as wavelength to the -4 power. In the case of blue photons compared to red photons, this means that blue photons are about 10 times more likely to get scattered than red photons. ... Watch the blue photons scatter away from the detector . ... Interstellar dust make stars appear redder than they really are . ...

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. ...

... Bad Astronomy . Misconceptions . ... Bad Astronomy : "We're light years more advanced than our competition!" ... Even the closest astronomical object, the Moon, is 400,000 kilometers away! ... A beam of light will travel 9,500,000,000,000 kilometers in one year. This distance is defined as a light year ; the distance light travels in a year. ... This is another example of Bad Astronomy; like a light year, a parsec is a unit of distance, not time (to be specific, it equals 3.26 light years) . ...

Galactic Wind Shells and High Redshift Radio Galaxies . ... M.Krause . Astronomy & Astrophysics, v.436, 845-851 . Very Light Jets II: Bipolar large scale simulations in King atmospheres [small version] . ... Simulations of Astrophysical Jets in Dense Environments . M.Krause, V.Gaibler & M.Camenzind . in: High Performance Computing in Science and Engeneering '05 eds.: E.Krause, W.J ger & M.Resch. ... M.Krause & M.Camenzind . ... Martin Krause & Paul Alexander . ... Martin Krause . ...

Tired light models invoke a gradual energy loss by photons as they travel through the cosmos to produce the redshift-distance law. ... The tired light model can not produce a blackbody spectrum for the Cosmic Microwave Background without some incredible coincidences. ... So the CMB must have come from a far away part of the Universe, and its photons will thus lose energy by the tired light effect. ... Assume that the CMB starts out as a T = (1+z)*T_o = 2.998 K blackbody, which is the blue curve. ...

... Submitted by Al Takeda on 09/24/2015 13:03:02 . Veil Nebula - Supernova Remnant . The Veil Nebula is a supernova remnant located in the Cygnus constellation. ... The entire Veil Nebula covers an area more than 3 degrees, which is 6 times the diameter of the full moon. ... AstroTech AT66, 66mm, f/5 ED Refractor using an AstroTech flat field corrector, SBIG STL-6303E monochrome CCD camera, Losmandy Gemini G-11 EQ mount. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...