Search Publications
Cepheids as distance indicators and stellar tracers
Bono, G.; Pietrinferni, A.; Braga, V. F.
We review the phenomenology of classical Cepheids (CCs), Anomalous Cepheids (ACs) and type II Cepheids (TIICs) in the Milky Way (MW) and in the Magellanic Clouds (MCs). We also examine the Hertzsprung progression in different stellar systems by using the shape of I-band light curves (Fourier parameters) and observables based on the difference in m…
Stellar occultations by trans-Neptunian objects
Sicardy, Bruno; Buie, Marc W.; Braga-Ribas, Felipe +2 more
Stellar occultations provide a powerful tool to explore objects of the outer solar system. The Gaia mission now provides milli-arcsec accuracy on the predictions of these events and makes possible observations that were previously unthinkable. Occultations return kilometric accuracies on the three-dimensional shape of bodies irrespective of their …
Cosmic ray feedback in galaxies and galaxy clusters
Pfrommer, Christoph; Ruszkowski, Mateusz
Understanding the physical mechanisms that control galaxy formation is a fundamental challenge in contemporary astrophysics. Recent advances in the field of astrophysical feedback strongly suggest that cosmic rays (CRs) may be crucially important for our understanding of cosmological galaxy formation and evolution. The appealing features of CRs ar…
The evolution of CNO elements in galaxies
Romano, Donatella
After hydrogen and helium, oxygen, carbon, and nitrogen—hereinafter, the CNO elements—are the most abundant species in the universe. They are observed in all kinds of astrophysical environments, from the smallest to the largest scales, and are at the basis of all known forms of life, hence, the constituents of any biomarker. As such, their study p…
A buyer's guide to the Hubble constant
Lahav, Ofer; Lemos, Pablo; Shah, Paul
Since the expansion of the universe was first established by Edwin Hubble and Georges Lemaître about a century ago, the Hubble constant H0 which measures its rate has been of great interest to astronomers. Besides being interesting in its own right, few properties of the universe can be deduced without it. In the last decade, a signific…
Magnetic fields of M dwarfs
Kochukhov, Oleg
Magnetic fields play a fundamental role for interior and atmospheric properties of M dwarfs and greatly influence terrestrial planets orbiting in the habitable zones of these low-mass stars. Determination of the strength and topology of magnetic fields, both on stellar surfaces and throughout the extended stellar magnetospheres, is a key ingredien…
Weighing stars from birth to death: mass determination methods across the HRD
Feuillet, Diane K.; Girardi, Léo; Stassun, Keivan G. +31 more
The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exist a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning …
Observations of galactic and extragalactic novae
Izzo, Luca; Della Valle, Massimo
The recent GAIA DR2 measurements of distances to galactic novae have allowed to re-analyse some properties of nova populations in the Milky Way and in external galaxies on new and more solid empirical bases. In some cases, we have been able to confirm results previously obtained, such as the concept of nova populations into two classes of objects,…
Precise radio astrometry and new developments for the next-generation of instruments
Rioja, María J.; Dodson, Richard
We present a technique-led review of the progression of precise radio astrometry, from the first demonstrations, half a century ago, until to date and into the future. We cover the developments that have been fundamental to allow high accuracy and precision astrometry to be regularly achieved. We review the opportunities provided by the next gener…
Pulsating white dwarfs: new insights
Kepler, S. O.; Córsico, Alejandro H.; Althaus, Leandro G. +1 more
Stars are extremely important astronomical objects that constitute the pillars on which the Universe is built, and as such, their study has gained increasing interest over the years. White dwarf stars are not the exception. Indeed, these stars constitute the final evolutionary stage for more than 95% of all stars. The Galactic population of white …