... User Guide ] Task: imdiff Purpose: Shift and expand an image to make it match another. ... No default. Key: in2 The second input image. ... Key: adjust This gives the name of an output image data-set, being a version of second image after adjustment. ... The following five parameters give the initial estimates for the various parameters that IMDIFF is trying to find. ... Key: expand This gives the initial expansion. ... Key: offset This gives the initial dc offset to apply to IN2. ...

... Still, for earthbound astronomers NGC 5548 is not just another pretty face-on spiral galaxy. Home to some 250 Cepheid variable stars and a recent Type Ia supernova explosion, key objects for astronomical distance determinations , NGC 5548 is one of 8 galaxies used in a new study that includes additional Hubble Space Telescope observations to improve the measurement of Hubble's Constant - the expansion rate of the Universe. ... NASA Official: Jay Norris. ... NGC 2683: Edge On Spiral Galaxy . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2011 March 30 . NGC 5584: Expanding the Universe . Credit: NASA , ESA , A. Riess (STScI/JHU), L. Macri (Texas A M Univ.) et al. Hubble Heritage ( STScI / AURA ) . ... The winding spiral arms of this gorgeous island universe are loaded with luminous young star clusters and dark dust lanes. ... About APOD | ...

... What is the evidence for the Big Bang? ... Has the time dilation of distant source light curves predicted by the Big Bang been observed? ... Ask your own question! ... In the empty Universe, one of the many possible definitions of distance does agree with the assumptions in this question: the angular size distance , and it does reach a maximum value of the speed of light times one half the age of the Universe. ... The standard Big Bang model is singular at the time of the Big Bang, t = 0 . ...

... Bad Astronomy . ... Mad Science . ... Universe Today . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... As we look farther out, to more distant objects, we see that they are rushing away from us. ... If the Universe is open, it will expand forever. ... If the Universe is flat, it is forever balanced between open and closed; it will expand forever, but always slowing, just balancing gravity. ... 2008 Phil Plait. ... Subscribe to the Bad Astronomy Newsletter! ...

... It turns out one possibility is a form of matter/energy invented by Einstein in the 1920s to make sure his equations of General Relativity did not predict the Expansion of the Universe. Although Einstein was willing to predict several things with his equations of General Relativity, he obviously thought an expanding Universe was too much, and so he invented the Cosmological Constant, which repels itself, and was meant to balance the force of gravity, and make the Universe static. ...

... Binary orbits in the acceleration/period plane . Circular Orbits . ... We first present the equations for the period and acceleration of a pulsar in an eccentric binary system as a function of its position in the orbit. ... In Freire, Kramer & Lyne (2001) (from where most of this text and following equations are taken), we describe in more detail how circular binary orbits can be determined from the observed periods and accelerations of the pulsar. ... where is the orbital period of the binary. ...

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Astronotes Armagh Planetarium's Stellar Blog! ... Planets . ... Our Galaxy . ... Weird and Fun . ... It came from another galaxy: This artistтАЩs impression shows HIP 13044 b, an exoplanet orbiting a star that entered our galaxy from beyond. ... HIP 13044 is one of tens of millions of stars in the тАЬHelmi streamтАЭ, stars that belonged to a dwarf galaxy consumed by our own Milky Way galaxy, some six to nine billion years ago. ... Tweets that mention ESO finds weird doomed planet from another galaxy | ...

S P E C I A L R E P OR T F F 62 ROM SLOWDOWN to SPEEDUP By Adam G. Riess and Michael S. Turner Distant supernovae are revealing the crucial time when the expansion of the universe changed from deceler ating to acceler ating tion. ... Gravity keeps us grounded. ... Although Einstein's general theory of relativity allows for gravity to push as well as pull, most physicists regarded this as a purely theoretical possibility, irrelevant to the universe today. ...

Isaac Newton on the British pound note . ... 1) In the absence of forces, a body at rest will stay at rest, and a body moving at a constant velocity in a straight line continues doing so indefinitely. 2) When a force is applied to an object ("body"), it accelerates in the direction of the force. ... The second law gives an explicit formula, and hence is the one most useful. ... Mach argued that Newton's laws boil down to one law: . ... Mass and force are now readily derived. ...

... Epistemology is a part of the study of Philosophy dealing with how we use our senses to know something about the world. ... Yet we know that we can be deceived by our senses. ... If we cannot always trust our senses, how can we ever know anything for certain about the world? ... A branch of epistemology that has come into vogue in the last 10-15 years is the problem of consciousness. ... What relationship is there between our conscious experience and the true nature of the physical world? ...

... Energy . ... The free ions and electrons in a plasma behave the same way. Knowing the temperature of the high atmosphere of Earth, or that of the Sun, we can calculate energies expected of ions and electrons found there. However, ions and electrons actually observed in space are often much, much more energetic, and may move at a respectable fraction of the velocity of light (300,000 km/sec or 186,000 miles/sec). ... Typical energy of an electron in the polar aurora. 40,000 ev . ... 50,000 ev . ...

... Tonight's Sky . ... Observing . ... Astronomy for Kids . ... How fast is the universe expanding? Astronomers independently confirm a value for the Hubble constant, a number that reveals the universe's size, age, and eventual fate. ... The Hubble constant, named for astronomer Edwin Hubble, who first observed cosmic expansion in 1929, is one of the fundamental numbers cosmologists use in describing our universe. ... Only registered members of Astronomy.com are allowed to comment on this article. ...

... Ten years ago a startling discovery stunned the astronomical community. ... This illustration reveals the changing rate of cosmic expansion: the shallower the curve, the faster the rate. ... Michael Turner of the University of Chicago coined the term "dark energy" to describe the unknown force that is hastening cosmic expansion. ... If you enjoyed this excerpt from a feature article and would like to receive our quarterly Mercury magazine, we invite you to join the ASP and receive 4 issues a year. ...

... For this one needs additionally to associate a weight with each attitude sample. ... time => real64Data(addColumn(binnedAttTab, 'TSTART', REAL64, 's')) raDeg => real64Data(addColumn(binnedAttTab, 'RA', REAL64, 'deg')) decDeg => real64Data(addColumn(binnedAttTab, 'DEC', REAL64, 'deg')) paDeg => real64Data(addColumn(binnedAttTab, 'PA', REAL64, 'deg')) isGood => boolData( addColumn(binnedAttTab, 'IS_GOOD', BOOLEAN)) weights => real64Data(addColumn(binnedAttTab, 'WEIGHTS', REAL64)) . ...

... Eventually galaxies came into being. ... These would form a halo around the galaxy with individual clusters constantly plunging in and out in memory of the original collapse. ... In 1929, five years after he had determined galactic distances, Hubble discovered that the red shifts of galaxies were proportional to their distances. ... However we know the universe does not expand freely and the mutual gravitational attraction of all matter pulls on retreating galaxies and restrains their dispersal. ...

Bigbang Forum Message . ... Big Bang | ... Gravity And The Big Bang . ... The poison of prejudice has infected the minds and hearts of an entire profession, ASTRONOMY (and cosmology). ... Because the universe is so big the Big Bang theory alone could not answer the question of how very distant galaxies seem to know about each other. ... www.astronomy.net . ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... Science User Portal . ... Galaxies . ... Star Clusters . ... Stars@ESO . ... New observations from ESOтАЩs Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. ... This allows them to make a map that shows the quantity of heavy elements present in different parts of a galaxy and also determine where in the galaxy star formation is occurring most vigorously....

... The group of radio emitting X-ray binaries (XRB's), such as SS433, Cyg X-3, LSI , Cir X-1, etc., exhibit highly variable bursting radio emission interpreted as synchrotron radiation from relativistic electrons. ... In this paper, a numerical model for radio outbursts in XRB's is developed. The model is based on a process of continuous injection of relativistic particles into a spherical expanding plasmon, ejected following a transitory supercritical accretion event onto the compact star. ...