Search Publications
High-resolution ALMA and HST imaging of κCrB: a broad debris disc around a post-main-sequence star with low-mass companions
Wyatt, M. C.; Bonsor, A.; Marino, S. +6 more
$\kappa \,$ CrB is an ~2.5 Gyr old K1 sub-giant star, with an eccentric exo-Jupiter at ~2.8 au and a debris disc at tens of au. We present ALMA (Atacama Large Millimetre/submillimetre Array) Band 6 (1.3 mm) and Hubble Space Telescope scattered light (0.6$\, \mu$m) images, demonstrating $\kappa \,$CrB's broad debris disc, covering an extent $50\!-\…
Discovering vanishing objects in POSS I red images using the Virtual Observatory
Rodrigo, C.; Solano, Enrique; Villarroel, B.
In this paper, we report a search for vanishing sources in POSS I red images using virtual observatory (VO) archives, tools, and services. The search, conducted in the framework of the VASCO project, aims at finding POSS I (red) sources not present in recent catalogues like Pan-STARRS DR2 (limiting magnitude r = 21.4) or Gaia EDR3 (limiting magnit…
Modelling the flare in NGC 1097 from 1991 to 2004 as a tidal disruption event
Zhang, Xue-Guang
In the letter, interesting evidence is reported to support a central tidal disruption event (TDE) in the known AGN NGC 1097. Considering the motivations of TDE as one probable origination of emission materials of double-peaked broad emission lines and also as one probable explanation to changing-look AGN, it is interesting to check whether there a…
Taxonomy of protoplanetary discs observed with ALMA
Ward-Thompson, Derek; Kirk, Jason; Parker, Raeesa
Many observations of protoplanetary discs studied with ALMA have revealed the complex substructure present in the discs. Rings and gaps in the dust continuum are now a common sight in many discs; however, their origins still remain unknown. We look at all protoplanetary disc images taken with ALMA from cycles 0 to 5 and find that 56 discs show cle…
A highly mutually inclined compact warm-Jupiter system KOI-984?
Schmitt, J. H. M. M.; Czesla, S.; Wang, X. +6 more
The discovery of a population of close-orbiting giant planets (≤ 1 au) has raised a number of questions about their origins and dynamical histories. These issues have still not been fully resolved, despite over 20 years of exoplanet detections and a large number of discovered exoplanets. In particular, it is unclear whether warm Jupiters (WJs) for…
3D mapping of the Wolf-Rayet nebula M 1-67: clues for post-common envelope evolution in massive stars
Guerrero, M. A.; Toalá, J. A.; Santamaría, E. +5 more
We present a 3D mapping of the Wolf-Rayet (WR) nebula M 1-67 around WR 124. We obtained high-resolution San Pedro Mártir (SPM) Manchester Echelle Spectrograph (MES) observations along 17 long-slit positions covering all morphological features in M 1-67. We are able to unveil the true morphology of M 1-67 and its kinematics by interpreting the SPM …
Two evolved close binary stars: GALEX J015054.4+310745 and the central star of the planetary nebula Hen 2-84
Reindl, Nicole; Irrgang, Andreas; Heber, Ulrich +3 more
As part of a survey to find close binary systems among central stars of planetary nebula, we present two newly discovered binary systems. GALEX J015054.4+310745 is identified as the central star of the possible planetary nebula Fr 2-22. We find it to be a single-lined spectroscopic binary with an orbital period of 0.2554435(10) d. We support the p…
New constraints on the minimum mass for thermonuclear lithium burning in brown dwarfs
del Burgo, C.; Martín, E. L.; Lodieu, N.
The theory of substellar evolution predicts that there is a sharp mass boundary between lithium and non-lithium brown dwarfs, not far below the substellar-mass limit. The imprint of thermonuclear burning is carved on the surface lithium abundance of substellar-mass objects during the first few hundred million years of their evolution, leading to a…
Statistics of BY Draconis chromospheric variable stars
de Grijs, Richard; Kamath, Devika; Chen, Xiaodian +1 more
We present an extensive catalogue of BY Draconis (BY Dra)-type variables and their stellar parameters. BY Dra are main-sequence FGKM-type stars. They exhibit inhomogeneous starspots and bright faculae in their photospheres. These features are caused by stellar magnetic fields, which are carried along with the stellar disc through rotation and whic…
High-contrast, high-angular resolution view of the GJ 367 exoplanet system
Brandner, Wolfgang; Calissendorff, Per; Cantalloube, Faustine +1 more
We search for additional companions in the GJ 367 exoplanet system and aim to better constrain its age and evolutionary status. We analyse high-contrast direct imaging observations obtained with HST/NICMOS, VLT/NACO, and VLT/SPHERE. We investigate and critically discuss conflicting age indicators based on theoretical isochrones and models for Gala…