Results 71 to 80 of about 20,255 (236)

Revisiting Variable Stars Near Globular Clusters South of −29° Declination

Astronomische Nachrichten, Volume 346, Issue 2, February 2025.
ABSTRACT We review an often‐cited but seldom‐accessed catalogue by Fourcade and Laborde (1966) of 785 variable stars near 47 southern Galactic globular clusters, and recover the locations of 85 stars that were not incorporated into subsequent variable star catalogues and hence have become “lost” to the literature.
Andrew C. Layden, Julia Evangelista, Sakshi Gupta, Mithilesh Mittameda, Eva Mulloy, Sohan I. Muslim, Tiyinoluwa Olushola‐Alao, Akul Rishi   +7 more
wiley   +1 more source

AGN Obscuration and the Unified Model

Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012
Unification Models of Active Galactic Nuclei postulate that all the observed differences between type 1 and type 2 objects are due to orientation effects with respect to the line of sight to the observer. The key ingredient of these models is the obscuring medium, historically envisaged as a toroidal structure on a parsec scale.
Stefano Bianchi, Roberto Maiolino, Guido Risaliti, Isabelle Gavignaud   +3 more
wiley   +1 more source

The deep eclipses of RW Aur revisited by long‐term photometric and spectroscopic monitoring

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow‐up observations. We performed multiband (BVRI) photometry of the system with the Cassegrain‐Teleskop‐Kamera II and the ...
Oliver Lux, Markus Mugrauer, Richard Bischoff   +2 more
wiley   +1 more source

An Empirical Extinction Curve Revealed by Gaia XP Spectra and LAMOST

The Astrophysical Journal
We present a direct measurement of extinction curves using corrected Gaia XP spectra of the common sources in Gaia DR3 and LAMOST DR7. Our analysis of approximately 370,000 high-quality samples yielded a high-precision average extinction curve for the ...
Ruoyi Zhang, Haibo Yuan, Bowen Huang, Tao Wang, Lin Yang, Gregory M. Green, Xiangyu Zhang   +6 more
doaj   +1 more source

The Panchromatic Hubble Andromeda Treasury. XX. The Disk of M31 is Thick

The Astronomical Journal, 2023
We present a new approach to measuring the thickness of a partially face-on stellar disk, using dust geometry. In a moderately-inclined disk galaxy, the fraction of reddened stars is expected to be 50% everywhere, assuming that dust lies in a thin ...
Julianne J. Dalcanton, Eric F. Bell, Yumi Choi, Andrew E. Dolphin, Morgan Fouesneau, Léo Girardi, David W. Hogg, Anil C. Seth, Benjamin F. Williams   +8 more
doaj   +1 more source

Reddening Behaviors of Galaxies in the SDSS Photometric System

, 2008
We analyze the behaviors of reddening vectors in the SDSS photometric system for galaxies of different morphologies, ages, and redshifts. As seen in other photometric systems, the dependence of reddening on the spectral energy distribution (SED) and the ...
Grebel E. K., Myung Gyoon Lee, Sungsoo S. Kim   +2 more
core   +1 more source

Non-uniform extinction in young open star clusters [PDF]

, 2001
The extinction law and the variation of colour excess with position, luminosity as well as spectral class in young open star clusters NGC 663, NGC869, NGC 884, NGC 1502, NGC 1893, NGC 2244, NGC 2264, NGC 6611, Tr 14, Tr 15,Tr 16, Coll 228, Tr 37 and Be ...
Sagar, Ram, Yadav, R. K. S.
core   +3 more sources

oMEGACat. VII. Tracing Interstellar and Intracluster Medium of ω Centauri Using Sodium Absorptions

The Astrophysical Journal
We investigate the foreground interstellar medium along the line of sight and intracluster medium of ω Centauri ( ω Cen) by measuring the equivalent width of Na I D absorptions from MUSE observations. The large line-of-sight velocity difference between ω
Z. Wang, A. C. Seth, M. Latour, J. Strader, M. Häberle, N. Neumayer, C. Clontz, S. Kamann, M. S. Nitschai, M. Alfaro-Cuello, A. Bellini, A. Feldmeier-Krause, M. Libralato, A. P. Milone, P. J. Smith, S. O. Souza, G. van de Ven   +16 more
doaj   +1 more source

Interpretation of the UV spectrum of some stars with little reddening

, 2000
The spectrum of five stars is analysed and explained by the superimposition of two components. One is the extinction of the direct starlight, with an extinction coefficient A which varies as the inverse of the wavelength across all the UV.
Zagury, F.
core   +1 more source

Properties of extragalactic dust inferred from linear polarimetry of Type Ia Supernovae [PDF]

, 2015
Aims: The aim of this paper is twofold: 1) to investigate the properties of extragalactic dust and compare them to what is seen in the Galaxy; 2) to address in an independent way the problem of the anomalous extinction curves reported for reddened Type ...
Baade, D., Clocchiatti, A., Cox, N. L. J., Hoeflich, P., Maund, J. R., Patat, F., Reilly, E., Spyromilio, J., Taubenberger, S., Wang, L., Wheeler, J. C., Zelaya, P.   +11 more
core   +3 more sources