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 . ...

... The concerns here are similar to those for observing bright targets; saturation and blooming of the bright companion PSF must not impact the faint target. Also, one may need to consider subtracting the PSF of the bright object, and effects which limit the accuracy of that subtraction. If the bright companion will saturate and bloom, it will be necessary to rotate the CCD so that blooming along the CCD columns does not obliterate the faint target. ...

... In one situation, we can use light from quasars to probe the material between us and them because that light may pass through one or more galaxies or gas clouds on its way to us. The gas inside the galaxies or the intergalactic clouds acts then as a filter, absorbing selected wavelengths from the quasar light. ... Light from a quasar must pass through clouds of gas and even faint galaxies -- each leaving its imprint on the light -- before we receive it here on Earth. ... Gravitational lensing . ...

... A radio galaxy is a galaxy that emits an unusually big amount of energy at radio wavelengths. ... Inside of each galaxy with an active nucleus (radio galaxies are among them) there must be a system of a "central machine" responsible for the colossal amount of the emitted energy from radio to gamma ranges. ... Sometimes a radio source in an active galaxy may flare again if the needed conditions appear (a new portion of matter would fall into the furnace of the "central machine"). ...

... Next: Unsupervised Catalog Classification Up: Object Detection and Previous: Classification of Objects . ... Multi-resolution allows for image analysis in terms of different scales. ... This approach is used for the detection (and subsequent analysis) of globular cluster systems around elliptical galaxies, and for image characterization and object trawling in large image databases. ... The applicability of this approach to object detection in large image collections has been investigated. ...

... Meade Series 4000 Nebular Filters incorporate the very latest in interference coatings technology. ... Technical Basis of the Meade Broadband Nebular Filter: As shown in the transmission graph below, the Meade Broadband Nebular Filter strongly rejects the light of sodium- and mercury-vapor lights as well as natural airglow and auroral emissions. ... Meade Series 4000 Narrowband Nebular Filters . ... Meade Series 4000 Oxygen-III Nebular Filters . ... Meade Series 4000 Photo-Visual Color Filters . ...

... 2013 July 28 . Hoag's Object: A Strange Ring Galaxy . ... This question came to light in 1950 when astronomer Art Hoag chanced upon this unusual extragalactic object . ... 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 the Snake ( Serpens ). ... About APOD | ...

... About the Sky Map Online, professional edition . The professional version of the Sky Map Online was reflected as the tool for amateure astronomers and for professional astronomers It provides the creation of maps with the magnitude limit for stars up to 21-st magnitude (limit of the First POSS) and field size from several arcmins to 80 by 60 degrees, what makes possible to use it for the following goals: . ... Guiding stars selection. ... Such objects are not recommended to use as guiding stars. ...

GALAXIES IN THE FIELD OF GRB 021004 I.V.Sokolov, Yu.V.Baryshev, T.A.Fatkhullin Results of the B,V,R,I investigations (counts, photometric red shifts, etc.) of the field of size ~ 4\'.3 x 4\'.3 centralized at the host galaxy of GRB 021004 are presented. ... The exposure times were: 3600s (B), 3600s (V), 2700s (R), 1800s (I). Photometric red shifts of these galaxies up to z ~ 3 were determined. Galaxies with a possible broad absorption at 2200A (in the rest frame) were selected. ...