... Credit: Don Goldman Explanation: Blown by fast winds from a hot, massive star, this cosmic bubble is huge. ... The massive star itself, a Wolf-Rayet star , is the bright blue one near the center of the nebula. ... Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. ... NASA Web Site Statements, Warnings, and Disclaimers . ... Thor s Helmet . Thor s Helmet (NGC 2359) and Planetary Nebula . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2013 December 24 . Sharpless 308: Star Bubble . ... Explanation: Blown by fast winds from a hot, massive star, this cosmic bubble is huge. ... The massive star that created the bubble, a Wolf-Rayet star , is the bright one near the center of the nebula. ... Budget Universe: Free APOD 2014 Calendar in PDF format . ... About APOD | ...

. Next: Evolution in low mass Up: Binary Neutron Stars Previous: X-ray Binaries . љ . љ љ . Figure 45: . Jon Bell . Thu Dec 19 15:15:11 GMT 1996

Next: Ejectors in Massive Binary Previous: Artificial Galaxy: Full Matrix . The first version of the Scenario Machine was aimed especially at the simulation of massive binary star evolution. ... First, there is a large class of intermediate mass binaries (say, consisting initially of 8 + 5 solar masses) that can also produce NS and thus lead to the formation of a bright X-ray source. ... Next: Ejectors in Massive Binary Previous: Artificial Galaxy: Full Matrix Mike E. Prokhorov . ...

... STScI-PRC98-11A STARING INTO THE WINDS OF DESTRUCTION: HST/NICMOS IMAGES OF THE PLANETARY NEBULA NGC 7027 The Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) has captured a glimpse of a brief stage in the burnout of NGC 7027, a medium-mass star like our sun. ... The material settles into a wind of gas and dust blowing away from the dying star. ... During this phase, intense ultraviolet radiation from the central star lights up a region of gas surrounding it. ...

... Stars . ... Cepheid variable stars have been known since the 18th century. ... Regularly brightening to a peak over days, weeks or months before fading these variable stars were remarkable curiosities to astronomers in past centuries.€а The term Cepheid is taken from the star Delta Cephei in the constellation of Cepheus, which was identified as variable€а in 1784 by the teenaged prodigy John Goodricke (1764-96). ... Tweets that mention Cepheids: Inconstant Stars which break the rules | ...

Some astronomers ignore low-mass stars because they aren t very bright. However, stars with initial masses between about 0.8 Msun and 8 Msun (AGB stars) play an important role as the main site of the slow neutron capture (s-)process, which produces roughly half of the elements heavier than iron. ... From this work, we will see have a better understanding of AGB nucleosynthesis, the chemical evolution of globular clusters, and the properties of helium-rich stars. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Astronomers from nearly a dozen countries will gather in Armagh during the final week of July to study the origin and evolution of magnetism in massive stars. ... An important question for astronomers, however, is whether stars much more massive than our Sun, and perhaps millions of times brighter, have equally strong magnetic fields, and the extent to which such magnetic fields affects the evolution of these massive stars. ...

... Wispy tendrils of hot dust and gas glow brightly in this ultraviolet image of the Cygnus Loop nebula, taken by NASA s Galaxy Evolution Explorer. The nebula lies about 1,500 light-years away and is a supernova remnant, left over from a massive stellar explosion that occurred between 5,000 to 8,000 years ago. ... The filaments of gas and dust visible here in ultraviolet light were heated by the shock wave from the supernova, which is still spreading outward from the original explosion. ...

... Science . ... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members . ... Science Users Information . ... Data Handling and Products . ... Science Data Products Forum . ... ESO Data . ... ESO Data Access Policy . ... ESO Science Newsletter . ... ESO astronomers often are working on scientific programmes and data sets that are suited for PhD theses. This page gives an overview over what is currently offered by Faculty astronomers. ... Thesis topic . ...

... Authors: Linda J. Smith 1 2 , Antonella Nota 1 3 , Anna Pasquali 1 , Claus Leitherer 1 , Mark Clampin 1 , Paul A. Crowther 4 We present new HST/FOS and ground-based long slit spectroscopic observations of the nebulae around the two LMC Luminous Blue Variables R127 (= HDE269858) and R143 (= HDE269929), and the Ofpe/WN9 star S119 (= HDE269687). ... We find that the circumstellar environment of R127 is complex and suggestive of two discrete ejections in the mass loss history of the central star. ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... A new bright LBV (Luminous Blue Variable) star was detected in M33 galaxy. LBV stars are the most massive stars in the final stages of evolution before exploding in of supernovae. ... The new LBV star (Fig.1) is the seventh in M33. ... It is one of the brightest LBV stars of the M33 galaxy. ... The brightest object is the core of the galaxy, - a compact star cluster comprising a supermassive black hole. The new LBV star N93351 is located down and to the left from the core. ...

... The HI - Star Formation Connection . ... Coffee . ... Dark Galaxies and Dark Matter . ... HI in Normal Galaxies . HI and Galaxy Evolution over Cosmic Time . ... How Galaxies Accrete Gas . ... The Billion Galaxy Survey . ... Searches for Dark Galaxies . ... Evidence for Dark Matter in Galaxies . HI in Galaxies: Overview . ... Open Questions in Normal Galaxies . ... Starburst galaxies and BCDs . ... HI Rich Galaxies . ... Open Questions in HI and Galaxy Evolution . HI and Galaxy Evolution . ...

Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System Characteristics Formation Exosolar Planets Class 3 Stars The Sun Stellar Evolution of Low and High Mass Stars Deaths of Stars Exotic Stars Class 4 Galaxies Galaxy Classification Formation of Galaxies Galactic Evolution ... So far, one planet has been studied by this method. ...

... Sunday , October 6, 2013 Standard quasar-like AGN Standard AGN have: · · · · · Luminous accretion disk (with X-ray corona) Bright line emission (ionised by disk) Dusty obscuring torus (emits in IR/sub-mm) Orientation-dependent observed properties Sometimes, extended radio jets Sunday , October 6, 2013 Another class of AGN Other AGN , exemplified by weak radio ... Sunday, October 6, 2013 Summary · · · · · · Not all AGN follow the "standard" accretion disk picture. ...

... Baffled, you turn to the waiter. ... The waiter smiles. ... Some prefer small stars while others insist that the larger they are the better they are. ... Of course," he adds, sensing your concern, "you are the guest of Chez Stella. ... Immediately you hear the "tock... tock... tock" of the stopwatch, and you gaze deep into the distant star. ... You hadn't noticed before, but it is giving off vast symmetric clouds of what looks like smoke or dust hanging in the space around the beautiful star. ...

... LMC Project Outline . NGC 1818 Initial Results . ... The Large Magellanic Cloud (LMC) is uniquely suitable for the study of massive star clusters at all stages of evolution. By combining HST observations of these clusters with N-body models we hope to understand the origin and evolution of rich star clusters in our own Galaxy, in the LMC, and beyond. ... We aim to combine our HST observations with N-body models to understand the formation and evolution of globular clusters. ...

... Future seminars . P a s t seminars . ... Radiation-driven winds from stars and Active Galactic Nucle" . ... It is now clearly understood that the problem of mass loss is crucially important both from the point of view of it’s influence on the evolution of stars and for the explanation of physical processes and observational data in active galactic nuclei (AGN). ... Absorption of the radiation by continuum opacity is responsible for such an evolutionary significant mass loss in cold massive stars. ...

... This paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...