M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Risks Comparable to NEOs . ... The Increasing Rate of Discovery of Asteroids . ... Comet and Asteroid Collision Probabilities . ... Extreme albedo comets and the impact hazard (PDF Format) . ... Asteroid Impact Animations . ... Workshop on Scientific Requirements for Mitigation of Hazardous Comets and Asteroids - 2002 . ... The Spaceguard Survey Report, 1992 (PDF) . Tsunami from Asteroid/Comet Impacts . ...

... Strange visual effects would appear as documented in the above relativistically-accurate animation . First of all, relativistic aberration would cause objects to appear to bunch up in front you. Next, the Doppler shift would cause the colors of forward objects to shift toward the blue, while things behind you would shift toward the red. ... NASA Web Site Statements, Warnings, and Disclaimers . ... Publications with keywords: motion - color . Publications with words: motion - color . ...

... October 22, 1995 . A Quasar - Galaxy Collision? Credit: NASA , HST , John Bahcall, Institute for Advanced Study. ... The large redshifts imply that these objects, now known as quasars (QUASi-stellAR objects), lie near the edge of the observable Universe. ... This Hubble Space Telescope image shows a quasar known as PKS 2349 (the star-like object near the center) and a galaxy (surrounding fuzzy patch), but the quasar is not at the galaxy's center! ... About APOD | ... NASA Technical Rep.: ...

... 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 ...

... This effect is visible in Figure 4.3 which shows a logarithmic stretch of the image resulting from a 100s exposure on a star of V magnitude 2.6 through filter F502N in the PC. Extreme overexposure of the Loral CCDs is not believed to cause any permanent effects, and therefore the WFPC2 does not have a bright object limit. ... Several other artifacts that are common in saturated stellar images are also obvious in Figure 4.3 . ... Figure 4.3: Saturated Stellar Image Showing Horizontal Smearing. ...

... Home Articles Observing Resources for Amateur Astronomers ? Part 1: Beginning Observers Observing Resources for Amateur Astronomers ? Part 3: Advanced Observers . ... Observing Resources for Amateur Astronomers - Part 1: Beginning Observers . Observing Resources for Amateur Astronomers - Part 2: Intermediate Observers . Observing Resources for Amateur Astronomers - Part 3: Advanced Observers . Observing Resources for Amateur Astronomers - Part 4: Magazines and Miscellany . ...

The Doppler shift is the effect of sound increasing or decreasing in pitch as an object moves towards or away from you. ... Light works the same way, except light is shifted to redder colours when an object is moving away, and to blue colours when an object is travelling towards us. ... Almost every object he observed had its light stretched to redder colours, indicating essentially everything in the Universe was moving away from us. ... So the Hubble constant tells us how old the Universe is. ...

... This chapter documents all the JavaScript objects, along with their methods and properties. ... Full entries for each object appear in alphabetical order; properties and functions not associated with any object appear in Chapter 2, "Top-Level Properties and Functions." ... Tables included in the description of each object summarize the object's methods and properties. Full entries for an object's methods and properties appear in alphabetical order after the object's entry. ...

Next: ZGSC (Compressed GSC) and XSKYMAP . ... This is a preliminary report on an investigation of the quality and properties of plates digitized during creation of the Guide Star Catalog (GSC). The results will be vital for reclassifying GSC objects. ... Many objects are measured on more than one plate, and thus have multiple catalog entries. ... Among the shortcomings of the GSC are: biased magnitudes and incorrect classifications for certain objects, presence of artifact objects. ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

... Since the reddening found for the stars in Table 13 was small, no reddening correction was attempted. ... These diamonds indicate the positions of very low mass, 3 Myr old, objects from the work of Burrows et al. ... This optical V versus R - I scheme is a very powerful method of detecting very low mass (VLM) objects. ... Because of this, young brown dwarfs are intrinsically no more difficult to observe in the optical than low mass stars at the age of Orionis. ...

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. ...

Turning the Camera Skyward . A reconfigured camera can take wide-field exposures of astronomical objects (constellations, the Milky Way, zodiacal light, moving artificial satellites, meteor showers, variable stars, etc.) to reveal much fainter objects and structures than seen by naked eye. ... This picture reveals objects more than 2.5 times fainter than can be seen by the naked eye, including not only stars but also the Orion nebula (M42), where new stars are being born. ...

... Planets . ... Earth Satellites . ... Monthly Sky Notes . ... As the sun sets in the west each evening, Jupiter, the largest planet in our Solar System, is rising in the east in the constellation of Aries, where it is visible throughout the night setting just before sunrise. ... On 28 October the Earth comes between the Sun and Jupiter, in opposition, meaning as the Sun sets in the sky Jupiter will rise. ... Also this month rising into the sky in the early hours of the morning is Mars the Red planet....

Blackholes Forum Message . Forums: . ... Black Holes And RedShift . ... Perhaps black holes really are the reproductive means of the universe.Could the black hole of a Quasar red-shift the electromagnetic energy trying to escape it? ... Perhaps black holes treat electromagnetic energy the same way. ... No one really knows enough about Quasars and black holes to say for sure but ask yourself this: Why would all the Quasars in the universe be moving away from the Milky Way? ... www.astronomy.net . ...

... 50 Weirdest Objects . ... Observing springtime deep-sky objects with a large telescope . ... What effect, if any, do the objects in the Kuiper Belt and Oort Cloud have on the orbits or characteristics of the eight major planets? ... KUIPTER BELT | OORT CLOUD . Kuiper Belt and Oort Cloud objects can exert gravitational effects on the planets, but the real question is whether such perturbations are detectable. ... Get instant access to subscriber content on Astronomy.com! ...

... Among these objects, the newly discovered Kuiper Belt Objects (KBO's) outside the orbit of planet Neptune (also known as Trans-Neptunian Objects) are of particular interest, but the meeting was also concerned with distant comets and some of the small moons of the outer planets. ... The Kuiper Belt is a zone outside the orbits of Neptune and Pluto in which icy solar system objects were expected to be present; the first was found in 1992. ... ESO Press Photo 41/98 . ... Send comments to <ips@eso.org> ...

... Meade Instruments Corporation . ... Autostar Computer Controllers . 497 Autostar . ... One of the most important advances in telescope control in the past 25 years, the Meade #497 Autostar Computer Controller turns the ETX into an automatic celestial object locating system. ... The #497 Autostar Computer Controller plugs into the control panel of ETX-90EC, ETX-105EC, and ETX-125EC telescopes and enables automatic location of more than 30,000 celestial objects. ... about meade | ... Meade 4M | ...

... Comet Animation . ... Comet structures are diverse and very dynamic, but they all develop a surrounding cloud of diffuse material, called a coma, that usually grows in size and brightness as the comet approaches the Sun. ... As comets approach the Sun they develop enormous tails of luminous material that extend for millions of kilometers from the head, away from the Sun. ... The evaporated molecules boil off and carry small solid particles with them, forming the comet's coma of gas and dust. ...