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Related papers: Multiband Optical Light Curves of Black-Widow Puls…

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We report the results of quasi-simultaneous optical and NIR photometry of the low-mass X-ray binary, 4U 1957+115. Our observations cover B, V, R, I, J, H and K-bands and additional time-series NIR photometry. We measure a spectral energy…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Pasi Hakala , Panu Muhli , Phil Charles

We analyze new, high quality multicolor light curves of four overcontact binaries: AK Her, HI Dra, V1128 Tau and V2612 Oph, and determine their orbital and physical parameters using the modeling program of G. Djurasevic and recently…

Solar and Stellar Astrophysics · Physics 2015-06-23 S. Caliskan , O. Latkovic , G. Djurasevic , I. Ozavci , O. Basturk , A. Cseki , H. V. Senavci , T. Kilicoglu , M. Yilmaz , S. O. Selam

We present commissioning data from the OSIRIS integral field spectrograph (IFS) on the Keck II 10 m telescope that demonstrate the utility of adaptive optics IFS spectroscopy in studying faint close-in sub-stellar companions in the haloes…

The number of spatially unresolved white dwarf plus main-sequence star binaries has increased rapidly in the last decade, jumping from only ~30 in 2003 to over 3000. However, in the majority of known systems the companion to the white dwarf…

Solar and Stellar Astrophysics · Physics 2016-08-31 S. G. Parsons , A. Rebassa-Mansergas , M. R. Schreiber , B. T. Gansicke , M. Zorotovic , J. J. Ren

The wealth of detections of millisecond pulsars (MSPs) in $\gamma$-rays by {\em Fermi} has spurred searches for these objects among the several unidentified $\gamma$-ray sources. Interesting targets are a sub-class of binary MSPs, dubbed…

High Energy Astrophysical Phenomena · Physics 2020-08-19 C. Braglia , R. P. Mignani , A. Belfiore , M. Marelli , G. L. Israel , G. Novara , A. De Luca , A. Tiengo , P. M. Saz Parkinson

Gaia observations have reignited interest in the optical and ultraviolet (UV) opacity problems of cool white dwarfs ($T_{\rm eff} \leq 6000$ K), which were thought to be resolved nearly two decades ago through the inclusion of Lyman…

The near-ultraviolet and optical (white-light) continuum radiation in M dwarf flares exhibits a range of observed characteristics, suggesting that the amount of heating at large optical depth varies among impulsive-type and gradual-type…

Solar and Stellar Astrophysics · Physics 2019-03-06 Adam F. Kowalski , Mihalis Mathioudakis , Suzanne L. Hawley

The binary system HESS J0632+057 was recently detected by {Fermi} to possess orbital modulated GeV emission. In this paper, we study the possibility that the compact companion of HESS J0632+057 is a pulsar. Under such a presumption, we…

High Energy Astrophysical Phenomena · Physics 2017-08-30 Shu-Xu Yi , Kwong Sang Cheng

With a spectral type of T10, UGPS J072227.51-054031.2 is one of the coolest objects known to date in the solar neighborhood. Multiple systems are relatively common among early and mid-T dwarfs. We search for faint and close companions…

Solar and Stellar Astrophysics · Physics 2015-05-19 H. Bouy , J. Girard , E. L. Martin , N. Huelamo , P. W. Lucas

We carried out light curve solutions of ten detached eclipsing eccentric binaries observed by Kepler. The formal errors of the derived parameters from the light curve solutions are below 1%. Our results give indications that the components…

Solar and Stellar Astrophysics · Physics 2016-05-25 D. Kjurkchieva , D. Vasileva

This study presents new, high-quality, optical photometric observations of three W UMa type contact binaries. The analysis of the corresponding light curves is made using Djurasevic's inverse problem method. To explain the light curve…

Solar and Stellar Astrophysics · Physics 2025-07-02 Marko Grozdanović , Gojko Đurašević

We present a photometric analysis of 19 DA and 13 DAO white dwarfs (WDs) with effective temperatures exceeding 60 kK, building on the spectral analysis reported in the first paper of this two-part study. By examining archival light curves…

Solar and Stellar Astrophysics · Physics 2026-01-19 Semih Filiz , Nicole Reindl , David Jones , Paulina Sowicka , Matti Dorsch , Thomas Rauch , Klaus Werner

We present the Photometry and Rotation Curve Observations from Extragalactic Surveys (PROBES) compendium of extended rotation curves for 3163 late-type spirals, with matching homogeneous multiband photometry for 1677 of them. PROBES…

Astrophysics of Galaxies · Physics 2022-09-22 Connor Stone , Stephane Courteau , Nikhil Arora , Matthew Frosst , Thomas Jarrett

We discovered Fe $K_{\alpha}$ complex emission and pulsation in two highly variable sources (4XMM J174917.7--283329, 4XMM J174954.6--294336). The equivalent widths of 6.4 and 6.7 keV lines of 4XMM J174917.7--283329 are $99^{+84}_{-72}$ and…

High Energy Astrophysical Phenomena · Physics 2023-03-15 Samaresh Mondal , Gabriele Ponti , Frank Haberl , Kaya Mori , Nanda Rea , Mark R. Morris , Sergio Campana , Konstantina Anastasopoulou

Wide-field time-domain photometric sky surveys are now finding hundreds of eclipsing white dwarf plus M dwarf binaries, a population encompassing a wealth of information and potential insight into white dwarf and close binary astrophysics.…

We report the results from a pilot study to search for black holes and other dark companions in binary systems using direct imaging with SHARK-VIS and the iLocater pathfinder "Lili" on the Large Binocular Telescope. Starting from known…

We present the results of a long-term periodicity search in a sample of $\gamma$-ray blazars within a multiwavelength context. These blazars have been selected from the Steward Observatory sample as part of its optical monitoring program…

High Energy Astrophysical Phenomena · Physics 2022-11-16 J. Otero-Santos , P. Peñil , J. A. Acosta-Pulido , J. Becerra González , C. M. Raiteri , M. I. Carnerero , M. Villata

The Kepler Mission has acquired 33.5d of continuous one-minute photometry of KPD 1946+4340, a short-period binary system that consists of an sdB and a white dwarf. In the light curve, eclipses are clearly seen, with the deepest occurring…

Black widows are close binary systems in which a millisecond pulsar is orbited by a companion a few per cent the mass of the sun. It has been suggested that the pulsar's rotationally powered $\gamma$-ray luminosity gradually evaporates the…

High Energy Astrophysical Phenomena · Physics 2020-05-20 Sivan Ginzburg , Eliot Quataert

Millisecond pulsars (MSPs) are prolific GeV $\gamma\text{-ray}$ emitters, and nearly 80\% of Fermi-LAT MSPs reside in compact binaries. We demonstrate that the companions in these compact MSPs binaries are also 511 keV annihilation line…

High Energy Astrophysical Phenomena · Physics 2025-09-05 Zachary Metzler , Zorawar Wadiasingh
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