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We report simultaneous UBVRI photo-polarimetric observations of the long period (7.98 h) AM Her binary V1309 Ori. The length and shape of the eclipse ingress and egress varies from night to night. We suggest this is due to the variation in…

Time resolved spectroscopy of the Intermediate Polar FO Aqr reveals the presence of multiple periodicities in the UV range. A strong orbital modulation dominates both continuum and emission line flux variabilities, while line velocity…

The Eclipse Mapping Method is an indirect imaging technique that transforms the shape of the eclipse light curve into a map of the surface brightness distribution of the occulted regions. Three decades of application of this technique to…

Solar and Stellar Astrophysics · Physics 2015-08-14 Raymundo Baptista

We report the analysis of $JHK_{s}$ light curves of the eclipsing dwarf nova IP Peg in quiescence. The light curves are dominated by the ellipsoidal variation of the mass-donor star, with additional contributions from the accretion disc and…

Astrophysics · Physics 2009-11-13 T. Ribeiro , R. Baptista , E. T. Harlaftis , V. S. Dhillon , R. G. M. Rutten

We apply an eclipse mapping technique to observations of the eclipsing magnetic cataclysmic variable HU Aqr. The observations were made with the S-Cam2 Superconducting Tunnel Junction detector at the WHT in October 2000, providing high…

Soft, potentially thermal spectral components observed in some ULXs can be fit with models for emission from cool, optically-thick accretion disks. If that description is correct, the low temperatures that are observed imply accretion onto…

High Energy Astrophysical Phenomena · Physics 2015-06-17 J. M. Miller , D. J. Walton , A. L. King , M. T. Reynolds , A. C. Fabian , M. C. Miller , R. C. Reis

Time-resolved eclipse spectroscopy of the nova-like variable UX UMa obtained with the HST/FOS on 1994 August and November is analyzed with eclipse mapping techniques to produce spatially resolved spectra of its accretion disc and gas stream…

Astrophysics · Physics 2009-10-30 R. Baptista , K. Horne , R. A. Wade , I. Hubeny , K. S. Long , R. G. M. Rutten

{\it GALEX} near ultraviolet (NUV) and far-ultraviolet (FUV) light curves of three extremely low accretion rate polars show distinct modulations in their UV light curves. While these three systems have a range of magnetic fields from 13 to…

Solar and Stellar Astrophysics · Physics 2015-05-18 Albert P. Linnell , Paula Szkody , Richard M. Plotkin , Jon Holtzman , Mark Seibert , Thomas E. Harrison , Steve B. Howell

The AUGER Collaboration has recently published the precise energy spectrum of cosmic rays above 1 EeV, which exhibits rich and interesting features. These features provide an opportunity to investigate the galactic propagation and…

High Energy Astrophysical Phenomena · Physics 2024-04-16 Weikang Gao , Dan Li , Wei Liu , Hua Yue , Hongbo Hu

Recently, brightness variations occurring on twice the accretion disk precession period in the old nova and permanent superhump system V603 Aql have been observed by Bruch & Cook (2018). In an attempt to detect a similar effect in other…

Solar and Stellar Astrophysics · Physics 2019-03-28 Albert Bruch

FU Ori objects are the most extreme eruptive young stars known. Their 4 to 5 magnitude photometric outbursts last for decades and are attributed to a factor of up to 10,000 increase in the stellar accretion rate. The nature of the accretion…

Solar and Stellar Astrophysics · Physics 2024-08-21 Adolfo S. Carvalho , Lynne A. Hillenbrand , Kevin France , Gregory J. Herczeg

Using ASCA observations of several X-ray bursters in the low spectral state Lx~1-5x10^{36} erg/s) restrictions on the parameters of the accretion disk and the boundary layer were obtained. The low state spectra of X-ray bursters observed…

Astrophysics · Physics 2007-05-23 M. Revnivtsev , M. Gilfanov , E. Churazov , R. Sunyaev

$\require{mediawiki-texvc}$ We study accretion disk emission from eight Seyfert $1 - 1.5$ active galactic nuclei (AGN) using far ultra-violet ($1300-1800$ ${\AA}$) slit-less grating spectra acquired with AstroSat/UVIT. We correct for the…

High Energy Astrophysical Phenomena · Physics 2023-06-28 Shrabani Kumar , G. C. Dewangan , K. P. Singh , P. Gandhi , I. E. Papadakis , P. Tripathi , L. Mallick

The prototype nova-like variable VY Sculptoris was observed by the IUE during four different optical brightness states of the system. The FUV flux level from the highest state to the lowest state declines by a factor of 28. We have carried…

Astrophysics · Physics 2009-11-13 Ryan T. Hamilton , Edward M. Sion

We report on high speed photometry of EX Dra in quiescence and in outburst. The analysis of the lightcurves indicates that the outbursts do not start in the outer disc regions. The disc expands during rise to maximum and shrinks during…

Astrophysics · Physics 2009-10-31 R. Baptista , M. S. Catalan , L. Costa

We analyse Sector 20 TESS photometry of the ultra-hot Jupiter WASP-12b, and extract its phase curve to study the planet's atmospheric properties. We successfully recover the phase curve with an amplitude of 549 $\pm$ 62 ppm, and a secondary…

Earth and Planetary Astrophysics · Physics 2021-02-08 Niall Owens , E. J. W. de Mooij , C. A. Watson , M. J. Hooton

We have constructed a detailed radiative transfer disk model which reproduces the main features of the spectrum of the outbursting young stellar object FU Orionis from ~ 4000 angstrom, to ~ 8 micron. Using an estimated visual extinction…

We report the analysis of time-series of infrared $JHK_s$ photometry of the dwarf nova V2051 Oph in quiescence with eclipse mapping techniques to investigate structures and the spectrum of its accretion disc. The light curves after removal…

Solar and Stellar Astrophysics · Physics 2020-01-08 Raymundo Baptista , Eduardo Wojcikiewicz

We have obtained Far Ultraviolet Spectroscopic Explorer (905-1187 Angstrom) spectra of the non-magnetic cataclysmic variable Z Cam during a period of quiescence. The spectrum resembles that of a hot (57,000 K) metal-enriched white dwarf. A…

Astrophysics · Physics 2009-11-10 Louise Hartley , Knox S. Long , Cynthia S. Froning , Janet E Drew

We present high-speed, three-colour photometry of the faint eclipsing cataclysmic variables XZ Eri and DV UMa. We determine the system parameters through two techniques: first, timings of the eclipse contact phases of the white dwarf and…

Astrophysics · Physics 2009-11-10 W. J. Feline , V. S. Dhillon , T. R. Marsh , C. S. Brinkworth
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