. Pulkovo Observatory of Russian Academy of Sciences is situated . near Saint-Petersburg. It was founded in 1839. 196140, Saint-Petersburg, Pulkovskoye chaussee 65/1 . English version . Russian version . This page has been accessed times since May 1, 1999.

Light element abundances in NGC 5128 from planetary nebulae Jeremy R. Walsh, ESO George H. Jacoby, WIYN Reynier Pelletier, Kapteyn Lab., Groningen Nic A. Walton, IoA, Cambridge Planetary nebulae · Low mass (~0.7-7M^ј ) main sequence stars undergo a planetary nebula (PN) phase at ages 0.1-10Gyr depending on initial mass , following the red-giant branch (RGB) and asymptotic g iant branch (AGB) to the white dwarf cooling track · L eng th of PN phase ~104 yr (depending on core mass ) · ...

What happens to a star heavier than five solar masses? ... Stars about ten solar masses probably behave like our five solar mass star until they reach the end of core-helium burning. ... The Crab nebula was formed after a massive explosion ripped a star apart in 1054. ... Today, the glowing outer layers of the star are still rushing away from a tiny star in the centre. ... An incredible explosion rips through the outer layers of the star, releasing colossal amounts of energy in a supernova explosion. ...

... The measured Mg2 index corresponds to a certain defined region of the object and, after systematic corrections applied to series of measurements, it is reduced to a common standard aperture (for galaxies only). The compilation of Mg2 measurements may be accessed in HyperLeda. mg2 is the Mg2 index in mag. The Mg2, as well as velocity dispersions, are standardized to an aperture r norm of 0.595 h -1 kpc, which is equivalent to an angular diameter of 3.4 arcsec at the distance of Coma. ...

... 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. ...

... Central IC 1805 . ... 22.09.2006 . ... Credit Copyright: Ken Crawford ( Rancho Del Sol Observatory ) Explanation: Cosmic clouds seem to form fantastic shapes in the central regions of emission nebula IC 1805. Of course, the clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula's newborn star cluster (aka Melotte 15). ... 2005 2006 . ... Publications with keywords: emission nebula - star formation . Publications with words: emission nebula - star formation . ...

We present Spitzer observations of the nearby dwarf starburst galaxy NGC 1705 obtained as part of the Spitzer Infrared Nearby Galaxies Survey. ... The nebular metallicity of NGC 1705 falls at the transition level of ~0.35 Zsolar found by Engelbracht and collaborators, below which PAH emission is difficult to detect; the fact that a system at this metallicity shows spatially variable PAH emission demonstrates the complexity of interpreting diffuse 8 О?m emission in galaxies. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2006 September 22 . Central IC 1805 . ... Explanation: Cosmic clouds seem to form fantastic shapes in the central regions of emission nebula IC 1805. Of course, the clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula's newborn star cluster (aka Melotte 15). ... About APOD | ... NASA Official: Jay Norris. ...

... Science . ... Science Users Information > Science and Technical Meetings > Conferences 2010 > Central Massive Objects: The Stellar Nuclei - Black Hole Connection . ... Science Users Information . ... Observing with ESO Telescopes . ... Science Software . ... ESO Science Newsletter . ... An ESO workshop for observers and theorists to discuss recent progress in our understanding of the formation and evolution of black holes and star clusters in the centres of galaxies and their connection to each...

... The department was founded in late sixties by Prof. D.Ya.Martynov, who for many years was also the director of Sternberg Astronomical Institute. At present time, the head of the department is Prof. A.M.Cherepashchuk, a pupil of D.Ya.Martynov and his successor as the director of SAI. Since Prof. Martynov, the scientific activity of the department was primarily related to binary stars. ... The department consists of 15 members most of which have Ph.D. in Astrophysics. ...

... Models of central engines (1) Potential of disk accretion onto stellar mass black holes: disk binding energy: thin disk life time: - accreted mass - disk outer radius - gravitational radius - Shakura­Sunyaev parameter Ultra-dense Hyper-Eddington neutrino cooled disks !! ... 1989); Neutron star + Neutron star Neutron star + Black hole White dwarf + Black hole Black hole + compact disk Burst duration: 0.1s ­ 1.0s Released binding energy: (1.2) Collapsars­ origin of long duration GRBs? ...

3) Planets and Brown Dwarfs . ... By its nature, this method is most sensitive to massive planets orbiting close to their stars. ... That means that some of the more massive extrasolar planets could actually be brown dwarfs (although the statistics of the finds suggest that most of them are not). ... Another possible difference between brown dwarfs and massive planets is how they are born. ... They would base the fundamental definition on the mode of formation: a planet is built from planetesimals. ...

Лаборатория Физики Звезд . ... Специальная астрофизическая обсерватория Российской академии наук . ... О лаборатории . ... Новые LBV звезды в галактике Туманность Андромеды .. Подробнее . Свидетельства сверхкритической аккреции на черную дыру в SS433 .. ... Сверхкритический аккреционный диск в SS433 .. ... Пространственная структура оболочки Новой V1494 Орла обнаружена на БТА .. ... Открыта новая LBV-звезда Галактики - двойник знаменитой LBV-звезды P Лебедя .. ...

... To determine a lower limit to the sensitivity of current observations to measurements of NS surface temperatures, we have used data from the Einstein Slew Survey (Elvis et al. 1990) to establish temperature limits for 275 pulsars which received nonzero exposure during the survey. ... Filled squares correspond to pulsars actually detected in the survey data; the smaller symbols correspond to upper limits to the count rates. ... Click here for plot of x-ray data vs. cooling curves. ...

... Since IRS 7 at the Galactic center was identified as a luminous red supergiant (Lebofsky et al. 1982), a lasting debate has been initiated whether the nucleus of the Milky Way galaxy had experienced a recent star formation episode. ... 1993). ... 1994). ... Tamblyn & Rieke (1993) and Schaerer (1994) proposed starburst models which would be able to account for a young stellar population at the Galactic center, although the origin of some peculiar hot stars still remains to be explained (Tamblyn et al...

... Flux density at 1 GHz (/Jy): 1040 . ... Notes: This is the remnant of the SN of AD 1054. ... Optical: Strongly polarised filaments, diffuse synchrotron emission, with `jet' faintly visible. ... VLA at 1.4 GHz, radio detection of `jet'. ... Velusamy 1985, MNRAS, 212, 359. ... Aller & Reynolds 1985, ApJ, 293, L73. ... Comparison of VLA observations at 74 MHz, 327 MHz, 1.5 GHz and 5 GHz for spectral index studies. ... VLA at 5 GHz (1".4) and HST multi-epoch observation for proper motion studies. ...

... According to the most popular cosmological paradigm, the greater part of the galaxy mass is accumulated in the dark matter halo. ... The polar ring galaxies (PRGs) reveal external rings or disks of gas, dust and stars rotating in a plane roughly perpendicular to the disk of the central galaxy. ... The shape of the dark halo in the model was chosen so as to achieve the best fit to the observed rotation of both galaxies themselves and their polar rings. ... The SPRC-7 galaxy. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Armagh Planetarium . ... Moon . ... Space Flight . ... One of the best-known lunar craters, Tycho is not especially large at some 85 km across. ... Bright and with prominent rays of material radiating from it, Tycho is a young crater; there has been little time for the slow and steady rain of micrometeorites to erode it. ... NASAтАЩs LRO recently took this evocative image of the steep slopes of TychoтАЩs central peak illuminated by the morning Sun. ...

The most massive black holes in the nearby Universe seem to largely be hosted by massive central cluster galaxies. The ultra-massive black hole in NGC 1277, reported by van den Bosch et al. based on a stellar kinematic measurement, is an extreme outlier in this respect. NGC 1277 is not a central cluster galaxy, but a lenticular galaxy in the Perseus Cluster, at a distance of about 3.8 from the central cluster galaxy. ...

... Tonight's Sky . ... Observing . ... Sky this Month . ... Astronomers dissect a giant stellar explosion . ... A meticulous analysis of the data has allowed astronomers to investigate the initial phases of this giant stellar explosion, which led to the ejection of matter at velocities close to the speed of light. ... Only registered members of Astronomy.com are allowed to comment on this article. ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter...