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 . ...

... Hoags Object: A Strange Ring Galaxy . ... Credit: R. Lucas ( STScI / AURA ), Hubble Heritage Team , NASA Explanation: Is this one galaxy or two? ... How Hoag's Object formed remains unknown, although similar objects have now been identified and collectively labeled as a form of ring galaxy . ... Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of Serpens . ... Ring Galaxy AM 0644 741 from Hubble . ... Polar Ring Galaxy NGC 4650A ...

... 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. ... This model only works on very highly saturated stellar images. ... Several other artifacts that are common in saturated stellar images are also obvious in Figure 4.3 . ...

... 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. ...

... 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. ...

... 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. ...

... 2002 September 9 . Hoag's Object: A Strange Ring Galaxy . ... On the outside is a ring dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. ... How Hoag's Object formed remains unknown, although similar objects have now been identified and collectively labeled as a form of ring galaxy . ... Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of Serpens . ... About APOD | ...

... 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. ...

In this image by NASA's Hubble Space Telescope, an unusual, ghostly green blob of gas appears to float near a normal-looking spiral galaxy. The bizarre object, dubbed Hanny's Voorwerp (Hanny's Object in Dutch), is the only visible part of a 300,000-light-year-long streamer of gas stretching around the galaxy, called IC 2497. ... This Hubble view uncovers a pocket of star clusters, the yellowish-orange area at the tip of Hanny's Voorwerp. ... NASA/ESA/W. Keel (Univ. of Alabama)/the Galaxy Zoo Team ...

... 8) Why does WolfEdit crash when I fill a large area? ... Use one of the four "man pointing a gun" icons in the top left corner of the palette. ... Use the Lift Control Panel item. You can only have a control panel which faces east or west - the north or south face will appear as a lift side panel, although it will work as a control panel. Similarly, a lift side panel viewed from the east or west will appear as a control panel, but won't work as one. ... Because you used the Get Info... box. ...

... An OBJECT column gives the name of the object observed (usually a star name). ... In critical cases, it is common practice to measure sky on two or more positions around a target object, and these positions must be identified. ... A general treatment of this problem requires a column called OBJECT, bearing the usual name of the object (as in the star tables); a column labelled STARSKY, to distinguish between star+sky, star alone, or sky alone; and additional columns to identify the sky position. ...

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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. ...

... Science . ... Science Users Information > Data Handling and Products > Data Reduction FAQ > How can I run the pipeline when there are no bright objects in the individual image? ... Observing with ESO Telescopes . ... The default use of the visir_img_combine recipe of the VISIR pipeline is with the "ref" option set to false. ... The VISIR pipeline will create the combination of the nodded images using the ESO SEQ CUMOFFSETX and ESO SEQ CUMOFFSETY offset information in the fits file headers. ...

... 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 ...

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

... The awsome spectacle of a brilliant comet, with its long ghostly tail streaming behind it, is a rare event. ... Only one other comet, Comet Halley, was seen so far from the Sun, giving scientists an opportunity to watch it as it slowly warmed up and sprouted a tail. ... Comets are the Rip Van Winkles of the solar system -- mini-worlds that have changed little during their 4.5-billion-year nap far from the Sun. ... Observing Comets . ... Once, comets inhabited the entire solar system. ...

... The ROSAT Bright Survey: II. Catalogue of all high-galactic latitude RASS sources with PSPC countrate CR > 0.2 s -1 . ... 1S We present a summary of an identification program of the more than 2000 X-ray sources detected during the ROSAT All-Sky Survey (Voges et al. 1999) at high galactic latitude, |b| > 30degr , with countrate above 0.2 s -1 . This program, termed the ROSAT Bright Survey RBS, is to more than 99.5% complete. ...

... Astrophysics Group . ... Pulsars . ... Stars ? ... The array was designed to detect compact radio sources such as these by virtue of the fact that they would scintillate (twinkle) when observed from the Earth through the interplanetary medium ? ... One of Antony Hewish?s research students, Jocelyn Bell, was set the task of operating the telescope and inspecting the daily charts for the kind deflections in the trace which occurred when a scintillating source passed over the array. ...