... The newly discovered example of a ring-shaped planetary nebula is about 15,000 light-years distant. ... Planetary nebulae are created by sun-like stars in a final phase of stellar evolution. But the Necklace Nebula's central star, near the center of a ring strongly tilted to our line of sight, has also been shown to be binary , a close system of two stars with an orbital period of just over a day. ... Those clouds were likely ejected about 5,000 years before the clouds forming the necklace. ...

... 2010 November 3 . The Necklace Nebula . ... The newly discovered example of a ring-shaped planetary nebula is about 15,000 light-years distant. ... Astronomers estimating the apparent age of the ring to be around 5,000 years, also find more distant gas clouds perpendicular to the ring plane, seen here at the upper left and lower right. Those clouds were likely ejected about 5,000 years before the clouds forming the necklace. ... About APOD | ... NASA Web Privacy Policy and Important Notices . ...

... B. Vicini, A. Natta, A. Marconi, L. Testi, D. Hollenbach, B.T. Draine . 1998, A&A, in press . ... 1998, ApJ, in press . ... L. Testi, F. Palla, A. Natta . ... Francesco Palla . 1998, The Physics of Star Formation and Early Stellar Evolution, eds. C.J. Lada and N. Kylafis, in press . ... 1998, in "The Molecular Astrophysics of Stars and Galaxies - A Volume Honouring Alexander Dalgarno", edited by T. W. Hartquist and D. A. Williams, Oxford University Press, in press . ... Star Formation Group . ...

... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Late Stages of Stellar Evolution . Welcome to the home page of the Late Stages of Stellar Evolution" We are a research group which operates within the Astrophysics Group of the Australia Telescope National Facility. ... To investigate the late stages of stellar evolution and in particular the role of stellar mass-loss in the evolution of asymptotic giant branch stars, proto-planetary nebulae and extremely massive stars. ...

... GSAOI Home . ... Science . ... Despite vast increase in our understanding of the evolutionary nature of planetary nebulae (PNe) during the last three decades, a central question remains: where is the missing mass? Theoretical evolutionary tracks predict that all stars with masses in the range 1.4-8 M Sun should become PNe. ... Clearly, much of the mass of the planetary nebula shell must remain un-ionized, and much of it may be in molecular form. ... The Magellanic Cloud PNe are ideal for this. ...

... Keywords: globular clusters,M3,photometry,HST . ... Perform the most accurate test of the ``stellar clock'' used in dating globular clusters. ... These data will provide the first complete sample of post-main sequence stars over the entire area of the cluster, and will allow the most stringent tests of stellar evolution and dynamics models. ... M3 contains the largest population of Blue Straggler Stars (BSS) detected in a globular cluster so far ( ). ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Stars . ... Space Flight . ... This image of the Tarantula Nebula comprises one of the largest mosaics ever assembled from Hubble photos and includes observations taken by HubbleтАЩs Wide Field Camera 3 and Advanced Camera for Surveys, combined with observations from the European Southern ObservatoryтАЩs MPG/ESO 2.2-metre telescope which trace the location of glowing hydrogen and oxygen. ... Subscribe to Astronotes . ...

... ESO, the European Southern Observatory . ... ESO's Governing Bodies . ... Travel and Contacts . Travel to ESO Headquarters . ... Green ESO . ... Survey Telescopes . ... Star Clusters . ... Stars@ESO . ... View shopping cart . ... ESO 3.6-metre telescope . ... MPG/ESO 2.2-metre telescope . ... ESO 1-metre Schmidt telescope . ... VST . ... The glowing jumble of gas clouds visible in new image make up a huge stellar nursery nicknamed the Prawn Nebula. ... Milky Way : Nebula : Type : Star Formation . ...

... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

... Astrophysics Group . ... Galaxy Formation and Evolution . ... Gas heating and outflows driven by accreting supermassive black holes (quasar phase) may affect the evolution of star formation in their host galaxy. ... The starburst galaxy M82, which expels dust and metal enriched gas out of its disk . ... The interstellar medium (ISM) plays a central role in galaxy evolution, providing the fuel for star formation and also hosting the ?fossil record? of the galaxy formation history. ...

... Tonight's Sky . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... space flight . exoplanets . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... Why can the Hubble Space Telescope see distant galaxies but not exoplanets? ... D espite Hubble's marvelous ability to image distant galaxies, the telescope isn't able to image extrasolar planets. Get instant access to subscriber content on Astronomy.com! ...

home education > activities . ... Quick math activity that asks students to calculate scale models of a binary star system with a black hole in it. [h] . ... Students use a radiometer and a light bulb with a dimmer switch to make connections between the temperature, color, and radiation output of a star. ... This demonstration, similar to the above, from the Exploratorium Snack-book of science activities, lets students demonstrate how molecules scatter light and change the colors of the beam. [m,h] . ...

... Inhomogeneous planetary nebulae: Carbon and Oxygen abundances, Astron. ... Abstract . text in English . ... text in Russian . ... Chemica evolution of the system of galactic planetary nebulae , Astrophysics, 45 , 451-463 (2002) . ... Evolution of Elemental Abundances in Planetary Nebulae, Astronomy Letters, 32 , 557-565 ( 2006 ) . ... text in Russian (0.23Mb) . ... He, C, N, and O Abundances in an Ensemble of Galactic Planetary Nebulae, Astronomy Letters, 35 , 518-533 ( 2009 ) . ...

Stars form from interstellar clouds rich in hydrogen....they shine for billions of years, gradually converting hydrogen into helium....when hydrogen is exhausted, they need to find other energy sources....they expand to become giants and supergiants....low-mass stars expel planetary nebulae and become white dwarfs....high-mass stars explode as supernovae, leaving a neutron star or black hole behind. ... What can they tell us about normal stellar evolution ? ... WWW contact: webmaster@star.arm.ac.uk . ...

... STScI-PRC95-45a CRUCIBLE OF CREATION: PANORAMIC HUBBLE MOSAIC ZOOMS IN ON MAELSTROM OF STAR BIRTH This spectacular color panorama of the center the Orion nebula is one of the largest pictures ever assembled from individual images taken with NASA's Hubble Space Telescope. ... Though this 2.5 light-years wide view is still a small portion of the entire nebula, it includes almost all of the light from the bright glowing clouds of gas and a star cluster associated with the nebula. ...

Bizyaev D., "The Argument Against Long Extragagalactic Distance Scale", Astron. ... Soviet Astronomy) 1997. ... Zasov A., Bizyaev D., "An Estimate of the Hubble Constant using a Criterion for Gravitational Stability of Gaseous Discs", Pis'ma v Astron. ... 1996. ... D.Bizyaev, "Types of galaxies", 1996, Zvezdochet, No 11, p.22 (in Russian) . D.Bizyaev, "The Hubble Constant", 1996, Zvezdochet, No 2, p.20 (in Russian) . D.Bizyaev, "Magellanic Clouds", 1995, Zvezdochet, No 6, p.12. (in Russian) . ...

... 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 . ...

Our publications in 1996 year . Lindner, U.; Einasto, M.; Einasto, J.; Freudling, W.; Fricke, K.; Lipovetsky, V.; Pustilnik, S.; Izotov, Y.; Richter, G. Astronomy and Astrophysics, v.314, p.1-12 (10/1996) . Thuan, Trinh X.; Izotov, Yuri I.; Lipovetsky, Valentin A . ... Edited by Daniel Kunth, B. Guiderdoni, M. Heydari-Malayeri, and Trinh Xu Thuan, 1996., p.607 . ... Edited by Daniel Kunth, B. Guiderdoni, M. Heydari-Malayeri, and Trinh Xu Thuan, 1996., p.587 . ... Thuan, Trinh Xuan; Izotov, Yu. ...

... Shustov B.M., Wiebe D.S. Dust expelling from the Galaxy ( abstract from the journal ). Astronomy Reports , 1995, 39 , 578-586 [AZh, 72 , 650-659]. Wiebe D.S., Shematovich V.I., Shustov B.M. Chemical and dynamical evolution of protostellar clouds: initial stages of collapse ( abstract from the journal ). ... Shustov B.M., Wiebe D.S., Tutukov A.V. Evolution of disk galaxies and loss of heavy elements into the intracluster medium. ... ApJ (Letters), 1998, 503 , L71-L74 ( astro-ph/9806155 ). ...

The project of the informational system creation on the problem of evolution of radio galaxies, as a part of the "Big Trio" project aimed on studing of distant radio galaxies, is designed. This system allows a user to operate with simulated curves of spectral energy distributions (SED) to estimate ages and redshifts by photometry data. Authors use SEDs of several models for different types of galaxies. ... The HTTP and e-mail access is organized to this system. ...