... 2006 December 19 . Massive Stars in Open Cluster Pismis 24 . Credit: NASA , ESA and J. M. ApellАniz ( IAA , Spain). Explanation: How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. ... Component stars would still remain near 100 solar masses, making them among the more massive stars currently on record. ... About APOD | ...

... December 30, 1998 . Supernova 1994D and the Unexpected Universe . Credit: High-Z Supernova Search Team , HST , NASA . Explanation: Far away, long ago, a star exploded. ... Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae . ... The large number and great distances to supernovae measured in 1998 have been interpreted as indicating that we live in a previously unexpected universe . ... About APOD > . ... NASA Technical Rep.: ...

Seven months ago, on Mar 19, 2008, at 09:12 Moscow time, a new star appeared on the sky. The Sun had already risen over the Russia, but people of the Western hemisphere might be able to see by their eyes a faint starlet near one of Bootes constellation stars. This starlet appeared and faded by an order of magnitude in a minute. Astronomers named it GRB080319B or, informally, the Naked-Eye Burst, as it was twice as bright as human eye can see a star. ... Royal Astronomical Society . ...

... Classes . ... classes that define a functional representation of the sky brightness More... class . casa::ComponentList . A class for manipulating groups of components. More... class . ... Base class for component shapes. ... Base class for model components of the sky brightness. ... A model component of the sky brightness. ... Base class for spectral models. ... Internal ComponentModels_module classes and functions. classes that define a functional representation of the sky brightness . ...

... Archives . ... The PCA and ICA is used for separating mixed components with some assumptions. ... The need of source separation methods in astronomy has led various adaptations of decomposition methods available. ... I rarely come up with a paper which gathered and summarized component separation methods applicable to astronomical data. In that regards, the following paper seems useful to overview methods of reducing dimensionality for astronomers. [arxiv:0805.0269] . ... Chandra Blog . ...

... Just above and to the right of the photograph's center are the four stars that mark the boundaries of the famous Southern Cross. The Tails of Comet Hyakutake . ... This photograph of Comet Hyakutake was taken the night of April 18th and highlights different components of the tail. ... Comet Hyakutake and a Cactus . ... Polaris, the north star, is the bright star seen just to the upper right of the comet's head. ... Comet Hyakutake is seen here just as the Sun sets on April 22. ... April . ...

Top] [Prev] [Next] . Serpens SVS 20 is a binary pre-main sequence star, whose components are separated by 1.5 arcsec. Although of very different brightness, both components have the same spectral energy distribution in the range 0.9 to 5 microns. Eiroa and Casali (1992) discovered that SVS 20 had a arc-shaped nebulosity, departing from the binary star towards the southwest. ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

On March 29, 2003, an exceptionally bright Gamma-Ray Burst (GRB) was discovered by the HETE-2 satellite (Vanderspek et al. ... 2003, GCN, 2020, 1), GRB 030329 is the nearest cosmological burst detected to date, and its extreme brightness can be attributed to its proximity. ... In the fourth epoch, 51 days after the burst, GRB 030329 appeared resolved at 15 GHz with a component appearing to the north east at 0.28 +/- 0.05 mas from the main component (Fig. a). ... days after the burst. ...

XMM-Newton CCF Release Note XMM- CCF -REL-143 Improved model of RGS instrumental Oxygen absorption A. M. T. Pollock December 19, 2002 1 CCF components CCF component VALDATE EVALDATE Blocks changed XSCS ag RGS1 EXAFS 0002 1999-01-01T00:00:00 H2O-P-CCD1 NO H2O-P-CCD2 H2O-P-CCD3 H2O-P-CCD4 H2O-P-CCD5 H2O-P-CCD6 H2O-P-CCD7 H2O-P-CCD8 H2O-P-CCD9 RGS2 ... 6 Test procedures  Use fv to look at the new les and ensure that the oxygen data agree with the data supplied by SRON Utrecht. ...

Russian . ... text in Russian) . ... The Behaviour of the Bz Component of the Magnetic Field in Coronal Mass Ejections . ... Cooperation of IZMIRAN and Sternberg Astronomical Institute in the Study of the Sublimational Component of the Solar Coronal Radiation . ... Solar Wind and Magnetic Storms in the 24th Solar Activity Cycle . ... text in English) . ... The Solar Corona in the Light of TRACE Observations . ... Expeditions of Irkutsk Astronomers to Total Solar Eclipses in 1981--2012 . ...

... Well, there are at least a million times more galaxies in the Universe than there are human beings! ... These newcomers are bigger and brighter than anything else in space, and if that wasn't interesting enough, they also glow bright green! This has led astronomers to name them 'green bean' galaxies (look at the little green bean-like spot in the middle of this space picture). ... We think that they shine so brilliantly because of a black hole at their centre. ...

The "ring of fire" seen by satellite cameras around the polar caps (picture below) is probably created by electrons leaking from the tail's plasma sheet, whose magnetic field lines form a somewhat imperfect trap. ... One possible explanation involves the close association between auroral arcs and electric currents which flow along field lines between the ionosphere and distant space ( Birkeland currents ). ... That produces an extra resistance to the flow of current. ...

... In collaborative work with David Garc?a Alvarez (an Observatory PhD student now at Harvard) and John Butler, an extensive study of the RS CVn binary HR1099 was completed leading to two papers; the first on Doppler imaging and the second on flare activity. Spectra for the Doppler imaging were taken at two different sites, Kitt Peak National Observatory (KPNO), Arizona, and Mount Stromlo Observatory (MSO), Australia, during the 1998 MUltiSIte COntinuous Spectroscopic (MUSICOS) campaign. ...

... Flux density at 1 GHz (/Jy): 2720 . ... 1991, ApJ, 373, 146. ... ADS . ... VLA at 1.4 GHz and 4.8 GHz (both 1".3), for polarisation studies. ... VLA at 1.4 GHz and 4.8 GHz, for proper motion studies. ... 151 MHz observations for bulk expansion studies. ... Chandra observations, showing outer shock. ... Fesen et al. ... Spitzer observations. ... Chandra observations of rim. ... 2006, ApJ, 636, 848. ... 2006, ApJ, 647, L41. -ray line observations. ... Spitzer and Chandra observations for 3-D structure...

Direct Electron Imaging Using Back Thinned CCD's . ... where, Vim is the maximum radial emission energy of photoelectrons from the cathode (eV), Vs is the cathode to anode voltage (V), k is the spatial frequency (2 p lp/mm), L is the cathode to anode spacing of the proximity focused diode (mm), d is the field-free region thickness(mm), h is the backscattering coefficient, (G/G 0 .) is the ratio of the average EBS gain of the secondary electrons to the primary gain, and W is the CCD pixel pitch (mm). ...

... On December 10th, 2005 the Technical Management Meeting was held, at which the decision had been taken to fill the Progress M-55 vehicle Propulsion System with the propellant components and compressed gases. On December 12th, 2005 Progress M-55 transport cargo vehicle was filled with the propellant components and compressed gases. ...

... V838 Mon is a member of a new class of eruptive variables which appear as a peculiar novae having late K-M type spectra in their outburst. Before its outburst, it was a wide binary system of B3V type stars. ... The B3V companion was seen in the outburst in the UV spectrum taken with HST (Rauch et al., ... In the latest spectra, the light of B3V companion was predominating in the short-wave photometric bands. ... CCD blue frames of V838 Mon before the eclipse (left) and in the eclipse (right). ...

... Moscow, Russia . ... March-October 2000 . ... Gusev A.S. Multicolor CCD Photometry of Six Lenticular and Spiral Galaxies. ... Gusev A.S., Park M.-G. Structure and stellar population of ringed barred galaxy NGC 2336 // Astronomy and Astrophysics, 2003, V.410, P.117-129. ... Gusev A.S. Photometric Properties of Bars in Galaxies // Astronomy Reports, 2000, V.44, N9, P.579-591. ... Gusev A.S. BVRI CCD Photometry of Pecular Galaxies NGC 5605 and NGC 5665 // Astronomy Reports, 2000, V.44, N9, P.569-578. ...

... Since moonshine is really reflected sunlight, the full Moon is on the average slightly brighter in mid-winter, when Earth is closest to the Sun. In addition, the distance of the full Moon also varies, due to the ellipticity ("eccentricity") of the Moon's orbit. On 22 December, 1999, the two effects combined to produce the brightest full Moon of the century. ... This year will be the first full moon to occur on the winter solstice, Dec. 22nd, commonly called the first day of winter. ...