Search Publications
YY Hya and its interstellar environment
Thorstensen, John R.; Fesen, Robert A.; Przybilla, Norbert +7 more
Context. During a search for previously unknown Galactic emission nebulae, we discovered a faint 36' diameter Hα emission nebula centered around the periodic variable YY Hya. Although this star has been classified as an RR-Lyr variable, such a classification is inconsistent with a Gaia distance of ≃450 pc. The GALEX image data also show YY Hya as …
The hot interstellar medium towards 4U 1820-30: a Bayesian analysis
Waters, L. B. F. M.; Costantini, E.; Mehdipour, M. +3 more
Context. High-ionisation lines in the soft X-ray band are generally associated to either interstellar hot gas along the line of sight or to photoionised gas intrinsic to the source. In the low-mass X-ray binary 4U 1820-30, the nature of these lines is not well understood.
Aims: We aim to characterise the ionised gas present along the line of …
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. VIII. Carbon and oxygen
Udalski, A.; Johnson, J. A.; Gould, A. +6 more
Context. Next to H and He, carbon is, together with oxygen, the most abundant element in the Universe and widely used when modelling the formation and evolution of galaxies and their stellar populations. For the Milky Way bulge, there are currently essentially no measurements of carbon in un-evolved stars, hampering our abilities to properly compa…
A MUSE view of the asymmetric jet from HD 163296
Snellen, I. A. G.; Girard, J.; Brinchmann, J. +5 more
Context. Jets and outflows are thought to play important roles in regulating star formation and disk evolution. An important question is how the jets are launched. HD 163296 is a well-studied Herbig Ae star that hosts proto-planet candidates, a protoplanetary disk, a protostellar jet, and a molecular outflow, which makes it an excellent laboratory…
NGTS-13b: a hot 4.8 Jupiter-mass planet transiting a subgiant star
Jordán, Andrés; Wheatley, Peter J.; Bayliss, Daniel +31 more
We report the discovery of the massive hot Jupiter NGTS-13b by the Next Generation Transit Survey (NGTS). The V = 12.7 host star is likely in the subgiant evolutionary phase with logg* = 4.04 ± 0.05, Teff = 5819 ± 73 K, M* = 1.30−0.18+0.11 M⊙, and R* = 1.79 ± 0.06 R⊙…
The TOPGöt high-mass star-forming sample. I. Methyl cyanide emission as tracer of early phases of star formation
Immer, K.; Testi, L.; Elia, D. +9 more
Aims: The TOPGöt project studies a sample of 86 high-mass star-forming regions in different evolutionary stages from starless cores to ultra compact HII regions. The aim of the survey is to analyze different molecular species in a statistically significant sample to study the chemical evolution in high-mass star-forming regions, and identify …
Outflows from GRB hosts are ubiquitous: Kinematics of z < 0.3 GRB-SN hosts resolved with FLAMES
Covino, S.; Della Valle, M.; Melandri, A. +12 more
The hosts of long duration gamma-ray bursts (GRBs) are predominantly starburst galaxies at subsolar metallicity. At redshifts z < 1, this implies that most of them are low-mass galaxies similar to the populations of blue compact dwarfs and dwarf irregulars. What triggers the massive star-formation needed for producing a GRB progenitor is still …
Properties of the Hyades, the eclipsing binary HD 27130, and the oscillating red giant ɛ Tauri
Snellen, I. A. G.; Grundahl, F.; Fredslund Andersen, M. +21 more
Context. The derivation of accurate and precise masses and radii is possible for eclipsing binary stars, allowing for insights into their evolution. When residing in star clusters, they provide measurements of even greater precision, along with additional information on their properties. Asteroseismic investigations of solar-like oscillations offe…
Pebbles in an embedded protostellar disk: the case of CB 26
Henning, Thomas; Zhang, Chuan-Peng; Launhardt, Ralf +2 more
Context. Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins.
Aims: We study the physical structure and grain growth in the edge-on disk that surrounds the ≈1 Myr old low-mass (≈0.55 M⊙) protostar embedded in the Bok globule CB26 t…
Probing galactic double-mode RR Lyrae stars against Gaia EDR3
Kovacs, Geza; Karamiqucham, Behrooz
Context. Classical double-mode pulsators (RR Lyrae stars and δ Cepheids) are important because of their simultaneous pulsation in low-order radial modes. This enables us to place stringent constraints on their physical parameters.
Aims: We use 30 bright galactic double-mode RR Lyrae (RRd) stars to estimate their luminosities and compare these…