Spitzer Space Telescope mid-infrared spectroscopy has been obtained for 15 carbon-rich protoplanetary nebulae (PPNe) in the Large Magellanic Cloud (LMC) and for two other such stars in the Small Magellanic Cloud (SMC). Of these 17 PPNe, the unidentified 21 ѕ®m feature is strong in 7 spectra, weak in 2 spectra, and very weak or questionable in 4 spectra. ... The remaining two objects show typical carbon-rich PPNe spectra with no 21 ѕ®m features. ...

Figure 1: An averaged OH 1612-MHz spectral profile of V1018 Sco, from 36 separate epochs of observations at Parkes. ... V1018 Sco (IRAS 17317-3331, OH354.88-0.54) is a well known OH/IR star with strong infrared and radio maser emission. The OH 1612-MHz maser spectrum of V1018 Sco, shown in Figure 1, has a double-peaked profile that is characteristic of asymptotic giant branch (AGB) stars where the maser emission occurs from the outer regions of an expanding circumstellar envelope. ...

... Right: cold gas traced by [CII] emission (red) accreting onto a primeval galaxy (green) at z=7.1 ( Maiolino et al. 2015 ) (image credit: ALMA Press Release ) . ... 2010 , Cicone, Maiolino et al. ... 2012 , Cicone, Maiolino et al. ... Right: observed distribution of the average stellar metallicities of passive and star forming galaxies in the local universe, supporting starvation/strangulation as primary quenching mechanism in low/intermediate mass galaxies ( Peng, Maiolino, Cochrane 2015 ). ...

... Star Atlas . ... solar system . ... stars . ... Observe the Solar System . ... What factors determine if a massive star (say, 100 solar masses) forms instead of a Sun-like star? ... Stars of all masses form from dense clumps within exceptionally cold molecular clouds. ... Massive stars tend to form at the centers of high-mass reservoirs of gas. Get instant access to subscriber content on Astronomy.com! ... A gamma-ray burst hints that LIGO's double black holes started as one massive star . ...

... 2016 February 5 . Massive Stars in NGC 6357 . ... Explanation: Massive stars lie within NGC 6357 , an expansive emission nebula complex some 6,500 light-years away toward the tail of the constellation Scorpius . In fact, positioned near center in this ground-based close-up of NGC 6357, star cluster Pismis 24 includes some of the most massive stars known in the galaxy, stars with nearly 100 times the mass of the Sun. ... About APOD | ... NASA Official: Phillip Newman Specific rights apply . ...

... Laboratory and theoretical modelling of the UV bump on the interstellar extinction curve is a very popular topic in dusty investigations. ... feature is illustrated by Fig. 10 where the profiles were calculated using the model of graphite spheres. Figure 10: Normalized extinction efficiencies for graphite spheres. ... The lower panel shows the summary extinction of two graphite spheres with radii and (from upper panel) taken in equal proportions. ...

... The J, H and K bands are characterized by a bright background, such a background is mainly due to the emission of atmospheric lines and of thermal radiation. ... If the source cover a large fraction of the slit, spectra off-source must be observed to adequately sample the sky background. ... The on chip integration time (time spent in each position of the slit) must not exceed 40 seconds in J and H bands and 60 seconds in K band. ... We suggest a sequence of 10 for each elementary integration time. ...

... Contacts . 2012: . ... We refined the fundamental parameters of the components, the orbital periods, and the conditions of photospheric heating of the secondary component by the ultraviolet radiation of the hot component. ... The observations of the star clusters associated with ultra-luminous x-ray sources (ULXs) in four galaxies on the 6-meter and VLT telescopes have shown that all the ULXs are located within 200pc of very young star clusters (younger than 5 million years). ... Archive . ...

Next: Radial velocity of the Up: Optical spectrum of IRAS04296 Previous: Observations and spectra reduction . ... However, molecular emission features are only very rarely observed in the optical spectra of PPNe. ... On the other hand, it is well known that cometary nuclei spectra show prominent Swan band emission. In both spectra of IRAS04296 we have discovered strong emission in the (0;0) and (0;1) bands of the Swan system of the molecule. ... Now consider the case of IRAS04296. ...

Next: Observations and reduction Up: The discovery of SN1998bv Previous: The discovery of SN1998bv . ... Since the life cycle of massive stars is very short (<30Myr), one can expect to observe more or less frequent SNe in galaxies where current intensive star formation takes place. ... 1998). ... The supernova SN 1998bv was discovered on April 6, 1998 in the galaxy HS 1035+4758 selected as an ELG candidate in the HSS. ... Figure 1: DSS image of the galaxy HS 1035+4758. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... Three sixth-form students from St Patrick's Grammar School, Armagh , used the Faulkes Telescope South in Australia in April to observe and measure HW Virginis , an unusual "binary" or double star system suspected to host one or two extrasolar planets orbiting the central stellar pair. ... Armagh Observatory and associated researchers hope to develop this work to look for further evidence of planet-hosting binary star...

... We will consider the rms, (K), for observations with a receiver of system temperature, T , frequency resolution, per polarization, and total integration time per observing cycle, . ... For ``in-band'' frequency switching, the line under investigation is always in the observing band. ... Position Switching or ``Out-of-Band'' Frequency Switching: Here the line is only observed for one half of the time, with noise being present all of the time. ...

Large sunspots were occasionally seen far in the past without any instruments, when the sun was dimmed by thick haze, but not much was remembered of those observations. ... Sunspot Cycle (1850 - 1975) . One who was greatly influenced by Schwabe's discovery was an English gentleman of independent means, Richard Christopher Carrington , who devoted himself to the study of sunspots. ... Carrington had seen a flare, of the rare variety that is visible in white light (only about 50 are known). ...

The large magnetic cloud caused by coronal mass ejection at the Sun on January 6, 1997 came to the Earth at early morning on January 10 and continue to interact with Earth's magnetosphere till January 11 (see for example home page of this event prepeared by Dr. M.Peredo http://www-istp.gsfc.nasa.gov/istp/cloud_jan97/event.html ). ... During the days discussed here INTERBALL-1 satellite was in the magnetosphere (MS) near its dusk flunk - see the Fig. 1 for compearing. ...

... Up: Data Analysis and Processing Techniques . ... Also, a method for quality control of CCD observations is suggested. ... Everyone who observes a celestial object using a CCD detects moving celestial objects as a ``by product''. ... We hope that our investigations may be useful for near-Earth space control and also for searches of the moving celestial objects through analysis of old and new CCD frames obtained at any amateur or professional astronomical observatory. ...

... The discovery of this radiopulsar is potentially important not only for confirming the theory of evolution of NS, but also for understanding processes occurring in stellar winds   from normal stars. After all, a radiopulsar orbiting in the semi-transparent stellar wind of a normal star is a sort of probe scanning an inhomogeneous plasma by pulsed radiation (Lipunov and Prokhorov, 1984)[ 110 ]. ... 1) absorption of radio waves (light curve); . ... This object is a radiopulsar orbiting a Be-star. ...

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. ...

... PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: Testing the non-universality of the low-mass end of the Initial Mass Function in massive Early-Type Galaxies . ... Observing with ESO Telescopes . ... ESO-MIDAS . ... The stellar initial mass function (IMF) in early-type galaxies and the internal distribution of their dark and luminous mass are two of the deepest and most puzzling open issues in modern astrophysics, each of great importance to our understanding of galaxy formation. ...

OBSERVATIONS OF COORBITAL SATELLITES OF SATURN Emel'yanov N., Varfolomeev M. Sternberg State Astronomical Institute, Moscow, e-mail : emelia@sai.msu.ru Institut de MИcanique CИleste et de Calcul des иphИmИrides, Paris, e-mail : emelia@imcce.fr Abstract. To improve the orbital parameters and masses of coorbital satellites of Saturn, Janus and Epimetheus, new observations of these satellites are necessary. ... IN: Saturn. ... New observations of Saturn's coorbital satellites" - Icarus. ...

... 8, ``Celestial Mechanics'', 2002 Using positional observations of minor planets for improving the orientation of star catalogue Yu. ... But expe­ rience shows that this kind of observations can be used succesfully for improving orientation parameters of star catalogues with respect to dynamical reference system. ... Observations of 90 selected minor planets were used in general solution for their orbital elements, orientation parameters and some parameters of phase re­ duction. ...