Related papers: An Unusual Eclipsing Blue Straggler V8-NGC 6752
Recently, a new class of white dwarfs (``slowly cooling WDs'') has been identified in the globular cluster M13. The cooling time of these stars is increased by stable thermonuclear hydrogen burning in their residual envelope. These WDs are…
We studied eight new doubly eclipsing stellar systems. We found that they are all rare examples of quadruple systems of 2 + 2 architecture, where both inner pairs are eclipsing binaries. Until now, such a configuration had only been proven…
Evidence is emerging that the luminous X-ray sources in the cores of globular clusters may often consist of, or perhaps even as a class be dominated by, ultracompact (P < 1 hr) binary stars. To the two such systems already known, in NGC…
We analyze extensive BVRI photometry and radial velocity measurements for three double-lined deeply-eclipsing binary stars in the field of the old open cluster NGC 7142. The short period (P = 1.9096825 d) detached binary V375 Cep is a high…
The visual A component of the Gliese 586AB system is a double-lined spectroscopic binary consisting of two cool stars with the exceptional orbital eccentricity of 0.976. Such an extremely eccentric system may be important for our…
The period distribution of contact binaries exhibits a very sharp short period cut-off at 0.22 days. In order to provide valuable information on this short period limit, we observed ten totally eclipsing contact binaries with orbital…
The evolutionary state of the 198 day eclipsing binary BM Cas is examined using spectra that cover five orbital cycles. Radial velocities measured from SiII 6347 and SiII 6371 track the motion of the primary, and a mass function is found…
We identify SDSSJ121010.1+334722.9 as an eclipsing post-common-envelope binary, with an orbital period of P ~ 3 hrs, containing a very cool, low-mass, DAZ white dwarf and a low-mass main-sequence star of spectral type M5. A model atmosphere…
We have used deep high-resolution multiband images taken at the ESO Very Large Telescope to identify the optical binary companion to the millisecond pulsar (PSR J1911-5958A) located in the halo of the Galactic Globular Cluster NGC6752. The…
An early-type, massive, short-period ($P_{\rm orb}=2^{\rm d}.310951$) eclipsing spectroscopic binary DN Cas has been re-visited with new spectral and photometric data. The masses and radii of the components have been obtained as…
Using multicolour photometry we have confirmed the binary nature of the new W-type W UMa eclipsing binary VSX J053024.8+842243 and established its primary eclipse ephemeris to be HJD = 2455924.38150(26) + 0.4322929(1) * E. Using the light…
We find that the emission line object OGLEJ005039.05-725751.4, a member of the cluster OGLE-CL SMC 64, exhibits a peculiar light curve pattern repeating with a recurrence time of 141.45 days. The light curve resembles periodic outbursts…
We used high-spatial resolution images acquired with the WFC3 on board HST to probe the population of variable blue straggler stars in the central region of the poorly studied Galactic globular cluster NGC 6541. The time sampling of the…
V455 Car is a southern oscillating eclipsing Algol-type system with an orbital period of 5.132888 days. Our first photometric solutions based on the Transiting Exoplanet Survey Satellite indicate that it is a semi-detached binary with the…
We present an analysis of a new, detached, double-lined eclipsing binary system with K7 Ve components, discovered as part of the University of New South Wales Extrasolar Planet Search. The object is significant in that only 6 other binary…
Accurate photometric CoRoT space observations of a secondary seismological target, HD 174884, led to the discovery that this star is an astrophysically important double-lined eclipsing spectroscopic binary in an eccentric orbit (e of about…
We present spectroscopic analyses of 17 faint blue stars in the globular cluster NGC 6752. Effective temperatures, surface gravities, and helium abundances are determined and compared to theoretical predictions. All stars are helium…
OO Aql is a rare W UMa-type eclipsing binary in which the two solar-type stars may have only recently evolved into contact. The binary has an unusually high mass ratio (0.84), and a relatively long orbital period (0.506 d) for it spectral…
Contact binary systems (also known as W UMa systems) consist of a pair of hydrogen-burning dwarf stars orbiting each other so closely that they share a common envelope. Although they are relatively common, there is as yet no established…
The blue-straggler binary WOCS 5379 is a member of the old (6-7 Gyr) open cluster NGC 188. WOCS 5379 comprises a blue straggler star with a white dwarf companion in a 120-day eccentric orbit. Combined with the orbital period, this helium…