Authors: M. Kama, M. Min and C. Dominik
A&A 506, 1199 (2009) Received 13 March 2009 / Accepted 27 July 2009
Keywords: stars: circumstellar matter, stars: planetary systems: protoplanetary disks
The solar Ba{\sf II} 4554 Å line as a Doppler diagnostic: NLTE analysis in 3D hydrodynamical model
Authors: N. G. Shchukina, V. L. Olshevsky and E. V. Khomenko
A&A 506, 1393 (2009) Received 12 March 2009 / Accepted 25 June 2009
Keywords: Sun: photosphere, Sun: granulation, line: formation, techniques: spectroscopic, hydrodynamics, radiative transfer
Magnetic evolution of superactive regions – Complexity and potentially unstable magnetic discontinuities
Authors: S. Criscuoli, P. Romano, F. Giorgi and F. Zuccarello
A&A 506, 1429 (2009) Received 12 March 2009 / Accepted 23 July 2009
Keywords: Sun: activity, Sun: magnetic fields, Sun: flares
Low-mass protostars and dense cores in different evolutionary stages in IRAS 00213+6530
Authors: G. Busquet, Aina Palau, R. Estalella, J. M. Girart, G. Anglada and I. Sepúlveda
A&A 506, 1183 (2009) Received 13 February 2009 / Accepted 27 July 2009
Keywords: stars: formation, ISM: individual objects: IRAS 00213+6530, ISM: clouds
PMAS optical integral field spectroscopy of luminous infrared galaxies – I. The atlas
Authors: A. Alonso-Herrero, M. García-Marín, A. Monreal-Ibero, L. Colina, S. Arribas, J. Alfonso-Garzón and A. Labiano
A&A 506, 1541 (2009) Received 9 February 2009 / Accepted 17 July 2009
Keywords: Galaxy: evolution, Galaxy: nucleus, galaxies: Seyfert, galaxies: active, infrared: galaxies
First AGILE catalog of high-confidence gamma-ray sources
Authors: C. Pittori, F. Verrecchia, A. W. Chen, A. Bulgarelli, A. Pellizzoni, A. Giuliani, S. Vercellone, F. Longo, M. Tavani, P. Giommi, G. Barbiellini, M. Trifoglio, F. Gianotti, A. Argan, A. Antonelli, F. Boffelli, P. Caraveo, P. W. Cattaneo, V. Cocco, S. Colafrancesco, T. Contessi, E. Costa, S. Cutini, F. D'Ammando, E. Del Monte, G. De Paris, G. Di Cocco, G. Di Persio, I. Donnarumma, Y. Evangelista, G. Fanari, M. Feroci, A. Ferrari, M. Fiorini, F. Fornari, F. Fuschino, T. Froysland, M. Frutti, M. Galli, D. Gasparrini, C. Labanti, I. Lapshov, F. Lazzarotto, F. Liello, P. Lipari, E. Mattaini, M. Marisaldi, M. Mastropietro, A. Mauri, F. Mauri, S. Mereghetti, E. Morelli, E. Moretti, A. Morselli, L. Pacciani, F. Perotti, G. Piano, P. Picozza, M. Pilia, C. Pontoni, G. Porrovecchio, B. Preger, M. Prest, R. Primavera, G. Pucella, M. Rapisarda, A. Rappoldi, E. Rossi, A. Rubini, S. Sabatini, P. Santolamazza, E. Scalise, P. Soffitta, S. Stellato, E. Striani, F. Tamburelli, A. Traci, A. Trois, E. Vallazza, V. Vittorini, A. Zambra, D. Zanello and L. Salotti
A&A 506, 1563 (2009) Received 4 February 2009 / Accepted 3 August 2009
Keywords: gamma rays: observations, catalogs
Radiative hydrodynamics simulations of red supergiant stars – I. interpretation of interferometric observations
Authors: A. Chiavassa, B. Plez, E. Josselin and B. Freytag
A&A 506, 1351 (2009) Received 3 February 2009 / Accepted 14 July 2009
Keywords: stars: supergiants, stars: atmospheres, hydrodynamics, radiative transfer, techniques: interferometric
Extrasolar planets and brown dwarfs around A–F type stars – VII. \theta Cygni radial velocity variations: planets or stellar phenomenon?
Authors: M. Desort, A.-M. Lagrange, F. Galland, S. Udry, G. Montagnier, H. Beust, I. Boisse, X. Bonfils, F. Bouchy, X. Delfosse, A. Eggenberger, D. Ehrenreich, T. Forveille, G. Hébrard, B. Loeillet, C. Lovis, M. Mayor, N. Meunier, C. Moutou, F. Pepe, C. Perrier, F. Pont, D. Queloz, N. C. Santos, D. Ségransan and A. Vidal-Madjar
A&A 506, 1469 (2009) Received 26 January 2009 / Accepted 27 July 2009
Keywords: techniques: radial velocities, stars: early-type, stars: planetary systems, stars: individual: \theta Cygni
Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253 – II. The magnetic field structure
Authors: V. Heesen, M. Krause, R. Beck and R.-J. Dettmar
A&A 506, 1123 (2009) Received 21 January 2009 / Accepted 29 July 2009
Keywords: galaxies: individual: NGC 253, magnetic fields, methods: observational, methods: data analysis, galaxies: halos, galaxies: ISM
Physical structure and water line spectrum predictions of the intermediate mass protostar OMC2-FIR4
Authors: N. Crimier, C. Ceccarelli, B. Lefloch and A. Faure
A&A 506, 1229 (2009) Received 12 January 2009 / Accepted 5 August 2009
Keywords: ISM: abundances, ISM: molecules, stars: formation
The bright galaxy population of five medium redshift clusters – II. Quantitative galaxy morphology
Authors: B. Ascaso, J. A. L. Aguerri, M. Moles, R. Sánchez-Janssen and D. Bettoni
A&A 506, 1071 (2009) Received 29 December 2008 / Accepted 2 July 2009
Keywords: galaxies: clusters: general, galaxies: structure, cosmology: observations
Dust in brown dwarfs and extra-solar planets – II. Cloud formation for cosmologically evolving abundances
Authors: S. Witte, Ch. Helling and P. H. Hauschildt
A&A 506, 1367 (2009) Received 11 December 2008 / Accepted 21 August 2009
Keywords: astrochemistry, methods: numerical, stars: atmospheres, stars: low-mass, brown dwarfs
The quiet Sun magnetic field observed with ZIMPOL on THEMIS – I. The probability density function
Authors: V. Bommier, M. Martínez González, M. Bianda, H. Frisch, A. Asensio Ramos, B. Gelly and E. Landi Degl'Innocenti
A&A 506, 1415 (2009) Received 18 November 2008 / Accepted 16 July 2009
Keywords: magnetic fields, polarization, turbulence, techniques: polarimetric, methods: data analysis, Sun: magnetic fields
Complexity in the sunspot cycle
Authors: G. Consolini, R. Tozzi and P. De Michelis
A&A 506, 1381 (2009) Received 2 October 2008 / Accepted 5 June 2009
Keywords: Sun: activity, Sun: sunspots, methods: statistical, chaos
Properties and nature of Be stars – 26. Long-term and orbital changes of \zeta Tauri
Authors: D. Ruždjak, H. Boži?, P. Harmanec, R. Fi?t, P. Chadima, K. Bjorkman, D. R. Gies, A. B. Kaye, P. Koubský, D. McDavid, N. Richardson, D. Sudar, M. Šlechta, M. Wolf and S. Yang
A&A 506, 1319 (2009) Received 4 July 2008 / Accepted 24 August 2009
Keywords: stars: early-type, binaries: spectroscopic, stars: emission-line, Be, stars: individual: \zeta Tauri
The massive Wolf-Rayet binary LSS 1964 (=WR 29) – II. The V light curve
Authors: R. C. Gamen, E. Fernández-Lajús, V. S. Niemela and R. H. Barbá
A&A 506, 1269 (2009) Received 2 May 2008 / Accepted 1 August 2009
Keywords: stars: binaries: close, stars: binaries: eclipsing, stars: binaries: spectroscopic, stars: Wolf-Rayet
Supernova progenitor stars in the initial range of 23 to 33 solar masses and their relation with the SNR Cassiopeia A
Authors: B. Pérez-Rendón, G. García-Segura and N. Langer
A&A 506, 1249 (2009) Received 5 April 2008 / Accepted 20 March 2009
Keywords: stars: evolution, ISM: kinematics and dynamics, ISM: supernova remnants, ISM: bubbles, ISM: individual objects: Cassiopeia A
The Hertzsprung-Russell Diagram of Star Clusters
The nearby stars are of all ages, which gives them
a broad variety of luminosities and colors. To see stars of the
same age, to see the effects of mass and composition alone on
a star's color and luminosity, one must examine star clusters.
All of the stars in a star cluster are born at about same time.
The open clusters scattered in the Galactic disk provide us with
collections of young stars. The ancient globular clusters that
swarm around the Galactic center provide us with collections of
old stars. By creating Herzsprung-Russell diagrams for both types
of star cluster—plots of the colors and luminosities of
stars—astrophysicists gain insight into how stars, especially
stars more massive than the Sun, change over billions of years.
Table of the 10 Brightest stars within 10 Parsecs of the Sun
Little more than 350 stars are known to be
within 10 parsecs of the Sun. Most of these are too dim
to see with the unaided eye. Several, however, are among
the brightest stars in the night sky. The 10 brightest are
listed in a table on this page, along with their distances,
apparent visual magnitudes, absolute visual magnitudes,
color indices, and stellar types.
The Hertzsprung-Russell Diagram of the Nearest Stars
The HR diagram of the stars within 10 parsecs is
presented on this page. The diagram reveals that we are
surrounded largely by two types of star: dark main-sequence
stars and degenerate dwarfs. Stars like the Sun are the
exception rather than the rule, and the more luminous A stars
and red giants are rather rare. The brilliant and massive
supergiant O and B stars, of which Rigel in the constellation
Orion is an example, are completely absent from the local
stellar neighborhood, despite their prominence in the night
sky. Most stars in the Galactic disk are much less luminous
than the Sun, and most of the stellar mass of the Galactic
disk is in these stars.