Results 21 to 30 of about 13,043 (174)

Composite grains: Application to circumstellar dust

Atti della Accademia Peloritana dei Pericolanti : Classe di Scienze Fisiche, Matematiche e Naturali, 2011
Using the discrete dipole approximation (DDA) we calculate the absorption efficiency of the composite grain, made up of a host silicate spheroid and inclusions of graphite, in the spectral region 5.0-25.0μm.
D. B. Vaidya, R. Gupta
doaj   +1 more source

Polarimetric variations of binary stars. II. Numerical simulations for circular and eccentric binaries in Mie scattering envelopes [PDF]

, 2001
We present numerical simulations of the periodic polarimetric variations produced by a binary star placed at the center of an empty spherical cavity inside a circumbinary ellipsoidal and optically thin envelope made of dust grains.
Bastien P., Brown J. C., Brown J. C., Brown J. C., Daniel J.-Y., Daniel J.-Y., N. Manset, P. Bastien, Simmons J. F. L., Simmons J. F. L.   +9 more
core   +3 more sources

Sudden Extreme Obscuration of a Sun-like Main-sequence Star: Evolution of the Circumstellar Dust around ASASSN-21qj

The Astrophysical Journal, 2023
ASASSN-21qj is a distant Sun-like star that recently began an episode of deep dimming events after no prior recorded variability. Here we examine archival and newly obtained optical and near-infrared data of this star.
Jonathan P. Marshall, Steve Ertel, Francisca Kemper, Carlos del Burgo, Gilles P. P. L. Otten, Peter Scicluna, Sascha T. Zeegers, Álvaro Ribas, Oscar Morata   +8 more
doaj   +1 more source

Disentangling the Origin and Heating Mechanism of Supernova Dust: Late-Time Spitzer Spectroscopy of the Type IIn SN 2005ip [PDF]

, 2010
This paper presents late-time near-infrared and {\it Spitzer} mid-infrared photometric and spectroscopic observations of warm dust in the Type IIn SN 2005ip in NGC 2906.
Chevalier, Roger A., Dwek, Eli, Fox, Ori D., Leisenring, Jarron M., Skrutskie, Michael F., Sugerman, Ben E. K.   +5 more
core   +3 more sources

The formation of polycyclic aromatic hydrocarbons in evolved circumstellar environments [PDF]

, 2010
The formation of Polycyclic Aromatic Hydrocarbons in the circumstellar outflows of evolved stars is reviewed, with an emphasis on carbon stars on the Asymptotic Giant Branch.
Cherchneff, Isabelle
core   +2 more sources

Oceans, Lakes, and Stromatolites on Mars

Advances in Astronomy, Volume 2020, Issue 1, 2020., 2020
Billions of years ago, the Northern Hemisphere of Mars may have been covered by at least one ocean and thousands of lakes and rivers. These findings, based initially on telescopic observations and images by the Mariner and Viking missions, led investigators to hypothesize that stromatolite fashioning cyanobacteria may have proliferated in the surface ...
Rhawn G. Joseph, Olivier Planchon, N. S. Duxbury, K. Latif, G. J. Kidron, L. Consorti, R. A. Armstrong, C. Gibson, R. Schild, Michael Kueppers   +9 more
wiley   +1 more source

The T Tauri star RY Tau as a case study of the inner regions of circumstellar dust disks [PDF]

, 2007
We study the inner region of the circumstellar disk around the TTauri star RY Tau. Our aim is to find a physical description satisfying the available interferometric data, obtained with the mid-infrared interferometric instrument at the Very Large ...
A. A. Schegerer, Adams, Akeson, Allen, Basri, Beckwith, Bertout, Bertout, Blandford, Blum, Boss, Bouwman, Calvet, Calvet, Calvet, Calvet, Ch. Leinert, Chiang, Chiang, Cohen, D'Alessio, D'Alessio, D'Alessio, Dominik, Draine, Draine, Dullemond, Dullemond, Dullemond, Duschl, Eiroa, Eisner, Eisner, Elias, Fendt, Folha, Gail, Gail, Hanner, Hartigan, Hartmann, Harvey, Herbig, Herbst, Herbst, Indebetouw, Isella, Jaffe, Johansen, Johns-Krull, Joy, Jäger, Kenyon, Klahr, Kornet, Kuhi, Königl, Landstreet, Laughlin, Leinert, Leinert, Leinert, Leinert, Leinert, Leinert, Lissauer, Lodato, Lucas, Lynden-Bell, Mannings, Mannings, Mathis, McCabe, Meeus, Millan-Gabet, Miyake, Monnier, Mora, Muzerolle, Najita, Nakajima, Natta, Natta, Padgett, Pascucci, Pavlyuchenkov, Petrov, Pickering, Pontoppidan, Preibisch, Pringle, Rodmann, Rydgren, S. Wolf, Schegerer, Siess, Sonnhalter, Strom, Th. Ratzka, Uchida, Ulrich, van Boekel, Vink, Vinkovic, Wehrstedt, Weidenschilling, Weinberger, Weingartner, Whitney, Wielen, Wolf, Wolf, Wolf, Wolf, Wood, Wurm, Wünsch, Wünsch, Yorke, Zajtseva   +119 more
core   +1 more source

Discovery of Reflection Nebulosity Around Five Vega-like Stars [PDF]

, 2001
Coronagraphic optical observations of six Vega-like stars reveal reflection nebulosities, five of which were previously unknown. The nebulosities illuminated by HD 4881, HD 23362, HD 23680, HD 26676, and HD 49662 resemble that of the Pleiades, indicating
David C. Jewitt, Desert F.-X., Dunkin S. K., James P. Lloyd, James R. Graham, Kalas P., Paul Kalas, Plets P., Sfeir D. M., Steven V. W. Beckwith, Sylvester R. J., Sylvester R. J., Sylvester R. J., Welsh B. Y.   +13 more
core   +2 more sources

Observing dust settling and coagulation in circumstellar discs: Selected constraints from high resolution imaging

, 2010
Circumstellar discs are expected to be the nursery of planets. Grain growth within such discs is the first step in the planet formation process in the core-accretion gas-capture scenario.
Beckwith, Bjorkman, Blum, Boss, Brauer, Brown, Cuzzi, Draine, Draine, Duchêne, Dullemond, Dullemond, D’Alessio, Garaud, Guilloteau, Gullbring, Güttler, J. Sauter, Kamp, Kemper, Kessler-Silacci, Kim, Lada, Langkowski, Lucy, Mathis, McCabe, Meeus, Mie, Neuhäuser, Ormel, Ossenkopf, Pinte, Przygodda, Robitaille, S. Wolf, Sauter, Schegerer, Schegerer, Shakura, Sicilia-Aguilar, Sicilia-Aguilar, Simon, Stapelfeldt, Stapelfeldt, Thamm, Weidenschilling, Weidling, Weingartner, Wilking, Witt, Wolf, Wolf, Wolf, Wood   +54 more
core   +1 more source

Silicates in D-type symbiotic stars: an ISO overview [PDF]

, 2007
We investigate the IR spectral features of a sample of D-type symbiotic stars. Analyzing unexploited ISO-SWS data, deriving the basic observational parameters of dust bands and comparing them with respect to those observed in other astronomical sources ...
Allen D. A., Anandarao B. G., de Graauw T., Evans A., Feast M. W., Formiggini L., Girard T., Jaeger C., Jaeger C., M. Contini, Martin-Pintado J., Muerset U., Nussbaumer H., Nussbaumer H., Nussbaumer H., P. Rafanelli, Pegourie B., Posch T., R. Angeloni, S. Ciroi, Schilke P., Webster B. L., Willson L. A.   +22 more
core   +2 more sources