In absolute terms, what is the brightest astronomical body in the universe?
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From the website taken among the other answers, I took this quasar with its 4 to 5 million - billions times brighter than the sun. If this light is the same as here around the sun, I consider that the total energy on a given sphere is a constant. But the energy density is directly related to the surface of the corresponding sphere. It growth to the second power of its radius. In other words, when the energy is 4 times the one of the sune, the earth has to be at 2 AU (300 000 000 km) from the sun to get the same light level. Having a 4 to 5 * 10^15 (million - billion) more light means 70 000 000 AU to get the same light level. Since 1 AU is 150 000 000 km, this means a 10^16 km away from the light source. This represents a 1000 light years of travel. The closest star, besides the sun, is a 4.5 light years.\nThat's bright !\n\nAnother source gives hypernovae as brightest. A value of 3 * 10^46 J is given as the same energy level as the universe (for two seconds). To have an analogous, it's necessary to go for the big bang theory. If we receive one joule per square meter and per day on earth from the sun, then the corresponding sphere for this flash is 5 millions light years big. That's brighter but damn short. Two seconds !\n\nI have a third candidate. It was much shorter and much brighter. The big band itself.
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Alpha Centauri is the brightest star in the constellation Centaurus and 3d-brightest star in the sky; also known as Rigil Kent or Rigil Kentaurus; 1992 position R.A. 14h39.1m, Dec. −60°49′. It is a yellow main-sequence star of the same spectral class (G2 V) as the sun and of about the same size and mass; its apparent magnitude is −0.26. Actually, Alpha Centauri is a triple-star system, the components being designated A, B, and C. Alpha Centauri C is also called Proxima Centauri because it is the closest star to the earth (other than the sun), at a distance of 4.28 light-years, components A and B are currently 4.34 light-years away. Proxima Centauri orbits about the common center of mass of the system with a period of more than 250,000 years, so that in about 125,000 years it will be more distant than A and B.\nThis is not counting the sun, friend.
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is it possible that this might be called the cat's eye nebula?  if so, go to hubblesite.org. no specific listing for "god's eye"
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if it is extemely bright, then it is most likely the planet Jupiter. The moon moves a lot each day, so you need to say exactly what day and time you saw it.
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Largest Star (By Size) - VV Cephei - 1900 times diameter of sun\n\nMost Luminous Star - LBV 1806-20 - 40,000,000 times luminous than the sun\n\nHowever, the brightest objects in our universe are the quasars... Check the links below for more info\n\nI hope these were the answers u were lookin for...
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reflection of light\n\nDuring daylight the sky has the appearance of a deep blue surface, but this is the result of the air scattering sunlight. [1] There is no "blue object" above the earth in any normal sense, so it is hard to say what object the sky is. The sky is thus sometimes defined as the denser gaseous zone of a planet's atmosphere. At night the sky has the appearance of a black surface or region scattered with stars. But if we then say that the sky is the entire visible universe, it would not be the same thing we see during the day.
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If you mean the bright object sometimes near the moon when it's low in the sky around sunset or sunrise, it's Venus, otherwise known as the morning star or evening star. Three ways to verify that it is Venus: \n1. After the Sun and moon, it's the next brightest natural object in the sky.\n2. It's never seen more than a couple of hours after sunset in the western sky or before sunrise in the eastern sky, though it's bright enough to sometimes be visible just before sunset or just after sunrise.\n3. With good binoculars resting on something solid (to prevent vibration) you can sometimes make out a disk (or some part of it, depending on phase). Venus is the only planet whose disk can be seen without a telescope.
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No. \n\nStar:\nA self-luminous celestial body consisting of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures\n\nPlanet:\nA nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves.\n\nSo, stars are self-luminous (have their own light) and are stationary. Planets don't produce their own light and revolve around a star.
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The number of stars in the visible universe is estimated to be 70 sextillion, or 70,000,000,000,000,000,000,000 [seven followed by twenty-two zeros].\n\nor\n\nWikipedia claims that the observable universe contains about 7 × 1022 stars, organized in about 100 billion galaxies, which themselves form clusters and superclusters. An Ask the Scientist response to this question claimed that there are about 10 billion (10^10) stars in an average galaxy, \nand there are about 10 billion galaxies that we can observe in the universe, so the answer is 100 billion billion or 10^20. I don't think it is an issue that we have a precise answer for as yet.
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The brightest stars, the ones you can see with the naked eye, are all B8 and B9.  Some of the dimmer ones are of other classes--B,A,F, and perhaps some cooler classes, too.
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Astronomer - the scince is Astronomy
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Actually the Hubble Space Telescope has an unlimited range. It can actually see ALMOST to the edge of the observable universe (..about 13.7-billion light years). For about the first 100,000 years of its existence, the universe was opaque.  Hubble can see no farther than this 100,000 year limit because there's nothing for it to see.
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It is an approximate way of measuring how big or bright or heavy something is.\n\nThe term comes from the brightness of stars. The brightest star in the sky is Sirius and there are about another dozen almost as bright (Vega, Aldebaran, Betelgeuse etc) that are collectively known as first magnitude stars. Not quite so bright are the second magnitude stars (eg a coupl of stars in The Plough are 2nd Magnitude, and so on down to the 5th and 6th magnitude stars, such as members of The Pleiades, which are only visible to the naked eye on bright, clear nights. And then even fainter stars that can only be seen with binoculars or a small telescope or a huge radio telescope.\n\nThe point is that star brightness is described in categories, in bands, which share similar properties eg "only able to be seen when there is a full moon out" or "supernovae". And it doesn't need to be more precise than that.\n\nThe phrase "to the nearest order of magnitude" is used widely outside of astronomy to indicate an approximate idea of what to expect, eg "How big a fine will I get for a parking offence? £100?"\n\nThe questioner is wanting to be reassured it is not £1,000 but more like £50 - £150.
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Sirius B is one of the most massive white dwarf known.  Its volume is about the same as Earth, but the mass is comparable to that of the Sun. Since the mass of the Sun is approximately 333000 times that of the Earth, and that Earth has a density of 5.5, we have a specific density of 1800000 for Sirius B. That means 1 cubic cm of Sirius B should have a mass of 1800000 g,\nor 1800 kg, or 1.8 tonne (about 2 tons). So, this is not quite the 50 tons you were told.\nThat said, one may have been talking about the *core* of the star, where density is evidently a lot higher than the average for the whole star.
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sun....its a star btw but there are stars bigger than the sun
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It is Olbers' Paradox.\n\nWhy isn't the night sky as uniformly bright as the surface of the Sun?  If the Universe has infinitely many stars, then it should be.  After all, if you move the Sun twice as far away from us, we will intercept one quarter as many photons, but the Sun will subtend one quarter of the angular area.  So the areal intensity remains constant.  With infinitely many stars, every angular element of the sky should have a star, and the entire heavens should be as bright as the sun.  We should have the impression that we live in the center of a hollow black body whose temperature is about 6000 degrees Celsius.  This is Olbers' paradox.  It can be traced as far back as Kepler in 1610, and was rediscussed by Halley and Cheseaux in the eighteen century; but it was not popularized as a paradox until Olbers took up the issue in the nineteenth century.
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It is called a QUAsi-StellAR Object or quasar.\n\nNowadays they are generally believed to be galactic cores with enormous black holes at their center.\n\nIt appears starlike (quasi-stellar) but is actually very different in size and what it's made of.