... September 25, 1997 . T Pyxidis: Recurrent Nova . ... Explanation: What happens when a thermonuclear blast occurs on the surface of a white dwarf star? ... Like other binary star systems which produce nova outbursts , T Pyx is composed of a dense white dwarf and a close companion star. An outburst occurs when the temperature and density of the sea of matter dumped from the companion onto the surface of the white dwarf reach the nuclear flash point for hydrogen . ... About APOD > . ...

... Bad Astronomy . ... Mad Science . ... Site Info . ... Public Talks . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... Who is this guy who calls himself "The Bad Astronomer?" ... First, yes, I am a real live astronomer (when people ask me what astronomers do, I tell them "They astronom !" ... These are emitted by powerful objects like black holes, exploding stars, and super-dense neutrons stars. ... Finally, am I really a bad astronomer? ... 2008 Phil Plait. ...

An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . ... Astronomers can also determine the speed a galaxy is moving by breaking up its light into its component colors, rainbow-fashion. ... This pattern is now called "the expanding universe", since the entire universe of galaxies seems to be moving away. ... The Ancient Universe - The Age of the Expanding Universe - The Age of the Oldest Stars - The Age of Light From Distant Galaxies - The Age of the Chemical Elements | ...

... For a hundred years, astronomers have been trying to pin down the exact distance to one of our nearest neighbouring galaxies, the Large Magellanic Cloud. ... In the case of the Large Magellanic Cloud, its distance was determined by looking at pairs of stars that orbit each other. ... Finding the accurate distance to the Large Magellanic Cloud is an important breakthrough, because the distance to stars in that galaxy can be used to find the distance to even more remote galaxies. ...

... The greater the distance, the smaller the parallax. ... That triangle has the same proportions as the much larger triangle ABC, and therefore, if the distance B'C to the thumb is 10 times the distance A'B' between the eyes, the distance AC to the far landmark is also 10 times the distance AB. ... The most distant objects our eyes can see are the stars, and they are very far indeed: light which moves at 300,000 kilometers (186,000 miles) per second, would take years, often many years, to reach them. ...

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... The expansion is measured as a number called the Hubble Constant . ... Our value is about 20% lower than the one got with the Hubble Space Telescope in 1994," said Dr Jim Lovell, leader of the team that made the measurement. The Hubble Constant is named after American astronomer Edwin Hubble, who in the 1920s found that other galaxies were moving away from ours. ... The Hubble Constant links the galaxy's distance with its speed." ... A short run-down on the Hubble Constant: . ...

... connection points . ... The point P3 is the connection between the horizontal and vertical actuators and is the axis of rotation for the tail gunner motion. processing: survey/020204/reduc We can compute P3,P5 (the moveable points) in dome centerline coordinates if we have the actuator distances and we know the positions of the above connection points in dome centerline coordinates for a given position of the tertiary (say the nominal focus position).(see actuator distances to dome centerline ). ...

November 2006 Astronotes 1 Candles in the Dark Image Credit: Wikipedia.org By Colin Johnston, Science Communicator Since the mid-ninteenth century astronomers have used the principle of parallax to measure the distance to other stars. ... How then can we tell, for example, that M31, the galaxy in Andromeda, is 2.2 million light years away? It would be straight-forward to tell how far away a star was if it was exactly the same brightness as our own Sun. ...

... Posts tagged ?distance measure? ... From arxiv/math.st:0708.0169v1 . Data-Driven Goodness-of-Fit Tests by L. Mikhail . ... ArXiv] Data-Driven Goodness-of-Fit Tests, Aug. ... Tags: consistency , distance measure , distribution , goodness-of-fit test , inverse problem , Neyman type , regularity condition , score . Category: arXiv , Fitting , Uncertainty | 1 Comment . ... Entries RSS . Comments RSS . ... vlk on [MADS] Parallel Coordinates . ... Entries (RSS) and Comments (RSS) . ...

... We have measured this "redshift" for the pink black holes, and allowed for it in our calculations. ... We see this effect in the emission from gas around these pink black holes, but it is far too small an effect to account for the pinkness. Thus the swirling motions of gas around or into the black holes cannot produc the colour. ... At first we thought that these things were normal blue black holes hidden behind clouds of interstellar dust, that absorbed the blue light and made them appear pink. ...

In order to measure the density of the Universe, it is necessary to sample a region that is larger than the scale on which the Universe becomes approximately homogeneous. ... When applied to clusters of galaxies we find a mass to luminosity ratio that implies a density of the Universe that is about 0.3 times the critical density. ... Thus the mass-to-muinosity ratio appears to vary with the size of the region measured, from 3 in the solar neighborhood to 30 in galaxies to 300 in clusters of galaxies. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . This is the catalogue for an exhibition at Armagh Observatory to coincide with the transit of Venus on 8 June, 2004. ... But, once the distance to one planet was known, all others would follow. It was as if the distance to Dublin from Armagh was known to be twice the distance to Belfast, but neither distance was actually known in miles. Section I . ... The 19th century transits of Venus . ... Armagh Observatory . ...

... ARTICLE: The Adventurous Search For The Astronomical Unit . ... Kepler himself had suggested to use the rare occasions of Venus transiting (crossing) the solar disk to measure our distance to the planet. ... Due to the orbital inclination of Venus against the ecliptic of 3.5°, a Venus transit is so rare that it happens only at intervals of 121.5 years, 8 years, 105.5 years, 8 years and so on. ... Crabtree witnessing the transit of Venus 1639 . ... Transits of Venus - The Quest for the Solar Parallax...