Astronomy Picture of the Day . The Dark River to Antares . ... 3.06.2008 . ... Credit: Mюximo Ruiz Explanation: Connecting the Pipe Nebula to the bright star Antares is a flowing dark cloud nicknamed the Dark River . ... Antares , the bright star that appears yellow just below the center of the frame, is embedded in the colorful Rho Ophiuchi nebula clouds. ... Publications with keywords: dark cloud . Publications with words: dark cloud . ... Dark Clouds of the Carina Nebula . Dark Cloud ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2004 August 9 . The Dark River to Antares . ... Explanation: Connecting the Pipe Nebula to the bright star Antares is a flowing dark cloud nicknamed the Dark River . The murkiness of the Dark River is caused by absorption of background starlight by dust , although the nebula contains mostly hydrogen and molecular gas. ... About APOD | ...

... Circumstellar disc of beta Pictoris: constraints on grain properties from polarization. To appear in the Astronomy & Astrophysics . abs , src , ps ] . ... Dust influx to Titan from Hyperion . ... abs ] . ... Characteristics of bulges and disks in interacting galaxies . ... Dust grains around Herbig Ae/Be stars: porous, cometary-like grains? ... To appear in the Astronomy & Astrophysics Supplement . ... Finally, Links may lead you to more options (e.g. via the LANL preprint system). ...

... 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. ...

... 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 ...

We present a time-lapse sequence of 20 near-infrared ( J and K band) snapshots of the central 20 20 of the Crab pulsar wind nebula, taken at subarcsecond resolution with the Hokupa`a/QUIRC adaptive optics camera on the Gemini North Telescope and sampled at intervals of 10 minutes and 24 hr. It is observed that the equatorial wisps and polar knots in the termination shock of the pulsar wind appear to fluctuate in brightness on kilosecond timescales. ...

Photon Scattering: Basic Principle of Photon Scattering . Audio Narration is available . No Scattering: Photon Source and Detector . ... For optical photons, scattering goes as wavelength to the -4 power. In the case of blue photons compared to red photons, this means that blue photons are about 10 times more likely to get scattered than red photons. ... Watch the blue photons scatter away from the detector . ... Interstellar dust make stars appear redder than they really are . ...

... SEARCH ASP SITE: Match ALL words Match ANY word . ... ASP Conference Series . ... Accidental Astrophysics: The Devil's In the Magnitudes, Part II . ... The star second to the Sun in brilliance is Sirius. ... Recall the magnitude system, passed down to us through a hundred generations of sky watchers, as a means of quantifying stellar brightness ("Accidental Astrophysics," May/June, p. 9). ... Yes, it is a magnitude difference, but that difference is due to the distance between us and the star. ...

... This beautiful new image shows a glowing cloud of cosmic dust (called a nebula) sitting boldly against a backdrop of shining stars. To the naked eye, thick clouds like these appear empty and dark, but some are actually home to the brightest nebulae and hottest young stars in the Universe! Stars are made of gas, so it is no surprise that they are born inside thick gassy clouds. But the clouds that give birth to stars also block our view of them growing within. ...

... August 6, 1998 . Infrared Horsehead . ... Explanation: This famous cosmic dust cloud was imaged in infrared light by the European Space Agency's Infrared Space Observatory (ISO) satellite. The false-color picture shows the bright infrared emission from dust and molecular gas in part of the Orion star forming region surrounding the Horsehead Nebula . In visible light, the horsehead-shaped dust cloud looks dark against a background of bright glowing gas. ... About APOD > . ...

... Armagh Planetarium . ... Universe . ... Continue Reading.. ... 2 Comments After entering the Twittersphere in 2010 Armagh PlanetariumтАЩs online presence has grown over the past few years encompassing the Astronotes blog and Facebook accounts. ... No Comments In July 2015 Belfast Met opened its doors to budding astronauts, pilots and app geniuses with a new series of STEM summer camps. ... Here you will find the latest news and views from the fascinating worlds of astronomy and space exploration. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... These noctilucent "night-shining" clouds (or NLCs) are believed to form by sunlight reflecting off ice crystals high in the atmosphere, and usually appear in the northwest to northeast. ... NLCs occur at very high altitudes, in excess of 50 miles high, in the region above the stratosphere known as the mesosphere and at first sight they look like cirrus clouds. ... Noctilucent Clouds, July 2006 . ... NLCs from Space . ...

... Extended Narrow-line Emission in the Bright Seyfert 1.5 Galaxy HE 2211-3903 Scharw chter, J. , Dopita, M.A., Zuther, J., Fischer, S., Komossa, S., Eckart, A. 2011, AJ, v. 142, Issue 2, August 2011, pp. ... The nearby QSO host I Zw 1: the stellar disk and adjacent objects Scharw chter, J. , Eckart, A., Pfalzner, S., Saviane, I., Zuther, J. 2007, A , v. 469, Issue 3, July III 2007, pp. ... Krips, M., Eckart, A., Neri, R., Zuther, J., Downes, D. Scharw chter, J. 2005, A , v. 439, Issue 1, pp. ...

Our publications in 2007 year Pustilnik, S. A.; Tepliakova, A. L.; Kniazev, A. Y.; Burenkov, A. N.; SAO; Russia; SAAO; Africa, South . eprint arXiv:0712.4205, submitted to Astrophysical Bulletin (SAO) (12/2007) . Pustilnik, S. A.; Tepliakova, A. L.; Kniazev, A. Y. eprint arXiv:0712.4007, submitted to Astron.Lett (12/2007) . ... Kniazev, A. Y.; Pustilnik, S. A.; Zucker, D. B. eprint arXiv:0707.4285, submitted to MNRAS (07/2007) . ... eprint arXiv:0707.4288 (07/2007) . ...

... 2004: . ... An increase in star brightness is followed by a decrease in asphericity and wind velocity to the point where stationary and even accreting fraction of the wind appears in extremely bright objects together with a flowing out fraction. ... Based on an analysis of observations obtained with BTA and on the published data it was found that degree of abnormality of energy distribution in continuum of magnetic chemically peculiar stars increases with an increase of their rotation period. ...

The red colors in this image show the galaxy M66 as it appears at the submillimeter wavelength of 850 microns, while the white background shows the galaxy as it appears in visible light. Regions of cold dust that appear as dark streaks in the white image glow brightly in the red image. ...

True Color Image Gallery: Galactic SNR | Magellanic Cloud SNR . ... Chandra Proposer's Guide pile up section ] During frame readout, the ACIS CCDs take 40 microsec to (parallel) transfer the charge by one pixel. As a result of this, each frame readout, each pixel is exposed for 40 microsec to a source (plus cosmic X-ray background) at each location along its column. ... Note also that the image does not just trail, it extends along the whole column. ... Chandra Supernova Remnant Catalog . ...

... Jitter is usually very small in magnitude and random in effect, and is not expected to lead to systematic throughput changes. ... However, such a change should lead to an obvious decline in the strength of the comparison lines at one end of the spectrum relative to the other and not an overall decline in counts. No such effect is seen (the counts decline evenly from one end of the spectrum to the other). ... The value changes steadily, but not by enough to account for the changes in counts seen. ...

. Home . Documentation . Watchouts . Help . Calibration . Installation . Software requirements . Download . Notice that SOC-only packages like deceit, newsiam, odfcheck, etc , may appear listed in the list of all packages but no documentation is available for any of them. SAS User's Guide . HTML . PDF . PS . HEASARC ABC Guide (not up to date) . HTML . PDF . ps.gz . Pages maintained by SAS librarian . Any question about SAS should be addressed to the XMM-Newton help desk . Updated on: August 31, 2007

The form on this Web page allows specifying a celestial position for which the full 4x4 degree NVSS FITS image is desired. ... Other services of the NVSS survey include: . ... NVSS Postage stamp (small FITS or jpeg file) server . direct ftp to NVSS 4x4 deg. FITS image and documentation server . NVSS source catalog and software ftp server - but please note that you will need to schedule an overnight job for a quiet time slot to download the 150Mb CATALOG.FIT file to avoid timeouts etc. ...