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相关论文: Massive Variability Surveys from Venezuela

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We describe an ongoing variable star search program and present the first reduced results of a search in a 19 square degree (4.4\circle x 4.4\circle) field centered on J2000 {\alpha} = 22:03:24, {\delta} = +18:54:32. The search was carried…

星系天体物理 · 物理学 2011-02-01 Michael D. Williams , E. F. Milone

Photometric variability in young stellar objects (YSOs) provides critical insight into the mechanisms of mass accretion, disk evolution, and circumstellar extinction in early stellar evolution. We present an analysis of day-timescale…

With a combination of adaptive optics imaging and a multi-epoch common proper motion search, we have conducted a large volume-limited (D $\le$ 75 pc) multiplicity survey of A-type stars, sensitive to companions beyond 30 au. The sample for…

We present both the technical overview and main science drivers of the fourth phase of the Optical Gravitational Lensing Experiment (hereafter OGLE-IV). OGLE-IV is currently one of the largest sky variability surveys worldwide, targeting…

太阳与恒星天体物理 · 物理学 2015-04-24 A. Udalski , M. K. Szymański , G. Szymański

As a part of our ongoing Volume-limited A-Star (VAST) adaptive optics survey, we have obtained observations of 26 binary systems with projected separations <100 AU, 13 of which have sufficient historical measurements to allow for refinement…

As deep spectroscopic campaigns extend to higher redshifts and lower stellar masses, the interpretation of galaxy spectra depends increasingly upon models for very young stellar populations. Here we present new HST/COS ultraviolet…

Detailed studies of intermediate/low mass pre-main sequence (PMS) stars outside the Galaxy have so far been conducted only for small targeted regions harbouring known star formation complexes. The VISTA Survey of the Magellanic Clouds (VMC)…

The SuperWASP Cameras are wide-field imaging systems sited at the Observatorio del Roque de los Muchachos on the island of La Palma in the Canary Islands, and the Sutherland Station of the South African Astronomical Observatory. Each…

Low-mass objects are ubiquitous in our Galaxy. Their low temperature provides them with complex atmospheres characterised by the presence of strong molecular absorption bands which, together with their faintness, have made their accurate…

太阳与恒星天体物理 · 物理学 2025-08-12 Pedro Mas-Buitrago

One of the most remarkable properties of massive stars is that almost all of them are found in binaries or higher-order multiple systems. Observations that cover the full companion mass ratio and separation regime are essential to constrain…

太阳与恒星天体物理 · 物理学 2023-10-18 Tinne Pauwels , Maddalena Reggiani , Hugues Sana , Alan Rainot , Kaitlin Kratter

Dynamic model atmospheres of Mira stars predict variabilities in the photospheric radius and in atmospheric molecular layers which are not yet strongly constrained by observations. Here we measure the variability of the oxygen-rich Mira…

太阳与恒星天体物理 · 物理学 2018-06-06 M. Wittkowski , G. Rau , A. Chiavassa , S. Hoefner , M. Scholz , P. R. Wood , W. J. de Wit , F. Eisenhauer , X. Haubois , T. Paumard

The Taiwanese-American Occultation Survey (TAOS) project has collected more than a billion photometric measurements since 2005 January. These sky survey data-covering timescales from a fraction of a second to a few hundred days-are a useful…

Photometric measurements are prone to systematic errors presenting a challenge to low-amplitude variability detection. In search for a general-purpose variability detection technique able to recover a broad range of variability types…

We performed an intensive photometric monitoring of the PMS stars falling in a field of about 10x10 arc-minutes in the vicinity of the Orion Nebula Cluster (ONC). Photometric data were collected between November 2006 and January 2007 with…

太阳与恒星天体物理 · 物理学 2009-11-05 A. Frasca , E. Covino , L. Spezzi , J. M. Alcala' , E. Marilli , G. Furesz , D. Gandolfi

We report the main results of our six year long intensive optical monitoring on blazars ON 231 (W Com), BL Lac, and 3C 273. Intensive optical monitoring is an indispensable tool to obtain well sampled light curves and thus to understand the…

天体物理学 · 物理学 2010-12-13 G. Tosti , S. Ciprini , E. Massaro , M. Maesano , F. Montagni , R. Nesci

We present the results of a 2-epoch variability survey in the Hubble Deep Field with the goal of investigating the population of AGN to z=1. The primary data sets analyzed for galactic variability are the original HDF observations obtained…

天体物理学 · 物理学 2009-11-10 Vicki L. Sarajedini , Ronald L. Gilliland , Christina Kasm

The Chandra Cygnus OB2 Legacy Survey is a wide and deep X-ray survey of the nearby and massive Cygnus OB2 association. The survey has detected ~8,000 X-ray sources, the majority of which are pre-main sequence X-ray emitting young stars in…

太阳与恒星天体物理 · 物理学 2015-11-13 Nicholas J. Wright , Jeremy J. Drake , Mario G. Guarcello , Vinay L. Kashyap , Andreas Zezas

We search OGLE-I photometric database for stars, which, as defined by formal criteria adopted by OGLE-I microlensing search, showed variability during only one out of 3 or 4 observing seasons. The results include 17 previously reported…

天体物理学 · 物理学 2007-05-23 Przemyslaw Wozniak , Michal Szymanski

We present the first edition of a catalog of variable stars found in the Magellanic Clouds using OGLE-II data obtained during four years: 1997-2000. The catalog covers about 7 square degrees of the sky - 21 fields in the Large Magellanic…