GAA - Grup d'Astronomia i Astrofísica: Recent submissions
Now showing items 1-12 of 377
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3D hydrodynamic simulations of white dwarf-main-sequence star collisions-II. Off-centre collisions
(Oxford University Press, 2025-04-01)
Article
Open AccessStellar collisions have garnered renewed attention for their role in the formation of peculiar objects, such as blue stragglers, and their potential to explain transients with atypical observational and spectroscopic ... -
The initial mass function based on the full-sky 20 pc census of ~3600 stars and brown dwarfs
(2024-04-01)
Article
Open AccessA complete accounting of nearby objects—from the highest-mass white dwarf progenitors down to low-mass brown dwarfs—is now possible, thanks to an almost complete set of trigonometric parallax determinations from Gaia, ... -
Efficient area coverage planning using approximation tiling heuristics for mosaic imaging with agile spacecraft
(2024-12-12)
Article
Restricted access - publisher's policyThis work focuses on the Area Coverage Planning Problem (ACPP) for optical cameras onboard agile spacecraft in space exploration missions. The objective is to determine the optimal observation path of the camera’s boresight ... -
The white dwarf binary pathways survey - X. Gaia orbits for known UV excess binaries
(Oxford University Press, 2024-03-19)
Article
Open AccessWhite dwarfs with an F, G, or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterized in terms of ... -
Exsolution process in white dwarf stars
(EDP Sciences, 2024-03-11)
Article
Open AccessContext. White dwarf stars are considered to be suitable cosmic laboratories for studying the physics of dense plasma. Furthermore, the use of white dwarf stars as cosmic clocks to date stellar populations and main sequence ... -
A spectroscopic and kinematic survey of fast hot subdwarfs
(EDP Sciences, 2024-10-22)
Article
Open AccessHot subdwarfs (sdO/B) are the stripped helium cores of red giants formed via binary interactions. Close hot subdwarf binaries with massive white dwarf companions have been proposed as possible progenitors of thermonuclear ... -
Main sequence dynamo magnetic fields emerging in the white dwarf phase
(EDP Sciences, 2024-11-26)
Article
Open AccessRecent observations of volume-limited samples of magnetic white dwarfs (WD) have revealed a higher incidence of magnetism in older stars. Specifically, these studies indicate that magnetism is more prevalent in WDs with ... -
J-PLUS: The fraction of calcium white dwarfs along the cooling sequence
(EDP Sciences, 2024-11-15)
Article
Open AccessWe used the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2) photometry in 12 optical bands over 2176 deg2 to estimate the fraction of white dwarfs with the presence of CaII H+K absorption ... -
Characterisation of the stellar wind in Cyg X-1 via modelling of colour-colour diagrams
(EDP Sciences, 2024-10-29)
Article
Open AccessContext. Cygnus X-1 (Cyg X-1) is a high-mass X-ray binary where accretion onto the black hole (BH) is mediated by the stellar wind from the blue supergiant companion star HDE 226868. Due to its inclination, the system is ... -
A population synthesis study of the Gaia 100 pc unresolved white dwarf-main-sequence binary population
(EDP Sciences, 2025-03)
Article
Open AccessContext. Binaries consisting of a white dwarf and a main-sequence star (WDMSs) are excellent tools for studying a wide variety of open problems in modern astronomy. However, due to selection effects, the currently known ... -
Primeval very low-mass stars and brown dwarfs – VIII. The first age benchmark L subdwarf, a wide companion to a halo white dwarf
(Oxford University Press, 2024-08-05)
Article
Open AccessWe report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV ... -
PHL 5038AB: is the brown dwarf causing pollution of its white dwarf host star?
(Oxford University Press, 2024-04-25)
Article
Open AccessWe present new results on PHL 5038AB, a widely separated binary system composed of a white dwarf and a brown dwarf, refining the white and brown dwarf parameters and determining the binary separation to be au. New spectra ...