Search Publications
On the post-common-envelope central star of the planetary nebula NGC 2346
Jones, David; Van Winckel, Hans; Boffin, Henri M. J. +1 more
The common-envelope phase is one of the most poorly understood phases of (binary) stellar evolution, in spite of its importance in the formation of a wide range of astrophysical phenomena ranging from cataclysmic variables to cosmologically important supernova Type Ia, and even recently discovered gravitational wave producing black hole mergers. T…
Modelling Kepler eclipsing binaries: homogeneous inference of orbital and stellar properties
Agol, E.; Kiefer, F.; Ali, A. +1 more
We report on the properties of eclipsing binaries (EBs) from the Kepler mission with a newly developed photometric modelling code, which uses the light curve, spectral energy distribution of each binary, and stellar evolution models to infer stellar masses without the need for radial velocity (RV) measurements. We present solutions and posteriors …
The WAGGS project - II. The reliability of the calcium triplet as a metallicity indicator in integrated stellar light
Kamann, Sebastian; Schiavon, Ricardo P.; Foster, Caroline +12 more
Using data from the WiFeS Atlas of Galactic Globular cluster Spectra, we study the behaviour of the calcium triplet (CaT), a popular metallicity indicator in extragalactic stellar population studies. A major caveat of these studies is that the potential sensitivity to other stellar population parameters such as age, calcium abundance, and the init…
New β Cep pulsators discovered with K2 space photometry
Aerts, C.; Bowman, D. M.; Burssens, S. +3 more
We present the discovery of three new β Cep pulsators, three new pulsators with frequency groupings, and frequency patterns in a B3Ib star, all of which show pulsations with frequencies as high as about 17 d-1, with K2 space mission photometry. Based on a Fourier analysis and iterative pre-whitening, we present a classification and eval…
A treatment procedure for GMOS/IFU data cubes: application to NGC 2835
Ricci, T. V.; Ferrari, Fabricio; Steiner, J. E. +3 more
We present a set of treatment techniques for GMOS/IFU data cubes, including correction of the differential atmospheric refraction; Butterworth spatial filtering, to remove high spatial-frequency noise; instrumental fingerprint removal; Richardson-Lucy deconvolution, to improve the spatial resolution of the observations. A comparison with HST image…
Hubble Space Telescope analysis of stellar populations within the globular cluster G1 (Mayall II) in M 31
Milone, A. P.; Bedin, L. R.; Rich, R. M. +5 more
In this paper, we present a multiwavelength analysis of the complex stellar populations within the massive globular cluster Mayall II (G1), a satellite of the nearby Andromeda galaxy projected at a distance of 40 kpc. We used images collected with the Hubble Space Telescope in UV, blue and optical filters to explore the multiple stellar population…
Flipping-up the field: gravitational feedback as a mechanism for young clusters dispersal
Kounkel, Marina; Hernández, Jesús; Román-Zúñiga, Carlos +3 more
Recent analyses of Gaia data have provided direct evidence that most young stellar clusters are in a state of expansion, with velocities of the order of ∼0.5 km s-1. Traditionally, expanding young clusters have been pictured as entities that became unbound due to the lack of gravitational binding once the gas from the parental cloud tha…
A connection between accretion states and the formation of ultrarelativistic outflows in a neutron star X-ray binary
Motta, S. E.; Fender, R. P.
The nearby accreting neutron star binary Sco X-1 is the closest example of ongoing relativistic jet production at high Eddington ratios. Previous radio studies have revealed that alongside mildly relativistic, radio-emitting ejecta, there is at times a much faster transfer of energy from the region of the accretion flow along the jet. The nature o…
Mapping the stability of stellar rotating spheres via linear response theory
Pichon, C.; Heggie, D. C.; Varri, A. L. +3 more
Rotation is ubiquitous in the Universe, and recent kinematic surveys have shown that early-type galaxies and globular clusters are no exception. Yet the linear response of spheroidal rotating stellar systems has seldom been studied. This paper takes a step in this direction by considering the behaviour of spherically symmetric systems with differe…
The Random Transiter - EPIC 249706694/HD 139139
Dai, F.; Vanderburg, A.; Jenkins, J. M. +16 more
We have identified a star, EPIC 249706694 (HD 139139), that was observed during K2 Campaign 15 with the Kepler extended mission that appears to exhibit 28 transit-like events over the course of the 87-d observation. The unusual aspect of these dips, all but two of which have depths of 200 ± 80 ppm, is that they exhibit no periodicity, and their ar…