... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2006 April 17 . Barnard's Loop around the Horsehead Nebula . ... Although glowing like an emission nebula , the origin of the bubble , known as Barnard's Loop , is currently unknown. ... To the left of the Horsehead Nebula , visible as the small dark indentation near the image top, is the photogenic Flame Nebula . ... About APOD | ...

Подписка на рассылку обзоров astro-ph на Subscribe.Ru . ... Предыдущий выпуск (N335) . ... Обсудить на форуме Scientific.RU . ... Подписка на рассылку обзоров на Subscribe.Ru . Обзоры препринтов astro-ph . ... Собственно обзоры препринтов. ... Ранее обзоры также были на Астронете и на Scientific.Ru . ... АНКи доступны на Астронете , а с 2006 по 2008 г. также на сайте Элементы.Ру . ... Ранее они также размещались на сайте Астронет и в архиве моих обозрений (кодировка KOI8) на сайте Scientific.Ru . ...

... Although glowing like an emission nebula, the origin of the bubble, known as Barnard's Loop , is currently unknown. Progenitor hypotheses include the wind s from bright Orion stars and the supernovas of stars long gone. ... Just to the right of the lowest star in Orion's belt is a slight indentation in an emission nebula that, when seen at higher magnification , resolves into the Horsehead Nebula . To the right of the belt stars is the bright, famous, and photogenic Orion Nebula . ...

... What work is currently being done to improve the flux calibration accuracy for echelle modes? ... Starting early in Cycle 11, monthly offsetting for echelle modes was turned off to minimize these types of calibration problems. ... We are currently working on redetermining the echelle flux calibration so that it is self-consistent with the 2-D scattered light algorithm. Time dependence of the sensitivity - Sensitivity-monitor data for the echelle modes are currently under investigation. ...

The choice of which type of electricity is called "positive" and which "negative" was made around 1750 by Ben Franklin, early American scientist and man of many talents. Franklin studied static electricity, produced by rubbing glass, amber, sulfur etc. with fur or dry cloth. ... Later, when electric batteries were discovered, scientists naturally assigned the direction of the flow of current to be from (+) to (-). ... Exploration" home page (index) Glossary . Official GSFC Home Page .. ...

... The choice of which type of electricity is called "positive" and which "negative" was made around 1750 by Ben Franklin, early American scientist and man of many talents (the stamp on the left commemorates his role as first US postmaster--and colonial postmaster before that). ... Franklin knew of two types of electric charge, depending on the material one rubbed. ... Later, when electric batteries were discovered, scientists naturally assigned the direction of the flow of current to be from (+) to (-...

... Users . ... Data Collection and Analysis . ... This particular part of the analysis has been disabled since the code is struggling to cope with the number of users seen this year, in particular the large contingent of people who have re-tweeted NASA. ... Order accounts: by user number (effectively random) by number of tweets (includes retweets) by number of followers by number of followers that also tweeted about AAS225 by number of friends that also tweeted about AAS225 . ... by user number . ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Astrophysics graduate student programs . ... Work experience for school students . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . ... Current telescope status . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Asteroid 2010 SO16 and the Earth follow similar orbits around . the Sun. ... out a horseshoe shape in space, taking 175 years to go from . ... Asteroid 2010 SO16 takes 175 years to make the trip from one end of the horseshoe to the other. ... Currently, three other horseshoe companions of the Earth are known to exist but, unlike 2010 SO16, these linger for a few thousand years at most before moving on to different orbits. ...

. The following is a list of the currently installed versions of the CIMA. The links refer to the CIMA version log page . Normal: version 3.0 - this is the next version of CIMA which has become the new default version --- NOTE that this version uses a new syntax for command file observations, uses new configuration files and needs source files with full velocity information . Old: version 2.2 - this is the old version of CIMA You can return to the main CIMA page by clicking here .

Using a combination of instruments on ESO's Very Large Telescope, astronomers have discovered the most massive stars to date, some weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses. The most extreme of these stars was found in the cluster R136 in the Tarantula Nebula. Named R136a1, it is found to have a current mass of 265 times that of the Sun. ...

... The ESO ADS mirror site is currently unavailable. ... Please use one of the ADS sites listed below. Harvard-Smithsonian Center for Astrophysics, Cambridge, USA . ... European Southern Observatory, Garching, Germany . National Astronomical Observatory, Tokyo, Japan . ... Beijing Astronomical Observatory, Beijing, China . Inter-University Centre for Astronomy and Astrophysics, Pune, India . ... Korea Astronomy Observatory . Send comments to <webmaster@eso.org> . ...

This lesson is intended as a revision of basic direct-current (DC) circuits . It was discovered in the 19th century that certain materials (so-called ideal resistors) have a current through them I that is proportional to the potential difference (voltage) across them V. This is not a fundamental law of physics (like momentum conservation) but is an observed behavior which some materials roughly follow (like the friction law we covered earlier in the course). ... This equation is called Ohm's law. ...

Next: Future plans Up: Electronic database Previous: Electronic database . The JPDOC gives access to references to the papers, data files and links to the internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to the radio domain. ... The database also provides links to internet collections of optical data files and personal WWW pages with relevant software and includes some other useful information. ...

. Other Relevant Links . Number counts have been illustrated earlier in the talk. QSO Clustering and Large-Scale Structure , Scott Croom et al . QSO Evolution and the Luminosity Function , B.J. Boyle et al . | Front page | . | << - Contamination | QSO close pairs - >> | . Robert J. Smith, ">rsmith@mso.anu.edu.au Last modified: Fri Sep 24 11:39:02 EST 1999 .

... 23 September 2004 - Telescope First Light! ... 30 July 2004 . ... NIC-FPS is an instrument combining the capabilities of a near-infrared imaging camera with a cryogenic Fabry-Perot etalon currently under development at the Center for Space Astrophysics and Space Astronomy , University of Colorado with support from Rice University , Ball Aerospace and the Astrophysical Research Consortium. It is scheduled to begin operations on the ARC 3.5m telescope at Apache Point Observatory in 2004. ...

Next: Modes of Operation Up: CCD Scientific Performance Previous: Field of View . Thermal excitation of charge carriers from the valence to the conduction band creates a dark current signal which may vary with position in the array, and also has temporal shot noise variation. ... In a device devoid of localized defects which give rise to individual dark current spikes , most dark current arises from electrons generated at interface states at the surface. ...

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... The star formation rate (SFR) of the current SF episode can be estimated from the total H luminosity. ... For the derived total flux F (H )=5.8 erg s -1 cm -2 we obtain a total H luminosity of 10 39 erg s -1 . ... The total mass of ionized gas can be obtained from the average mass density inside the H II region and its volume. An average mass density corresponding to the average electron density of 1 cm -3 within a volume with a diameter of 0.5 kpc yields a total ionized gas mass of 10 6 . ...

... Astrophysics Group . ... FIRST . ... This site is an initiative by MRAO Cambridge to provide improved access for the UK to the images being produced from the FIRST survey. ... Note that a small image returned by this server will have different gridding and orientation from an image of corresponding position and size returned by the FIRST CUTOUT server at the main site. ... This site may evolve to provide more of the facilities available at the FIRST main site in due course. ...