Search Publications
Forbidden hugs in pandemic times. II. The luminous red nova variety: AT 2020hat and AT 2020kog
Lundqvist, P.; Reichart, D. E.; Rest, A. +32 more
We present the results of our monitoring campaigns of the luminous red novae (LRNe) AT 2020hat in NGC 5068 and AT 2020kog in NGC 6106. The two objects were imaged (and detected) before their discovery by routine survey operations. They show a general trend of slow luminosity rise, lasting at least a few months. The subsequent major LRN outbursts w…
Deciphering the evolution of the Milky Way discs: Gaia APOGEE Kepler giant stars and the Besançon Galaxy Model
Anders, F.; Chiappini, C.; Figueras, F. +13 more
Context. Thanks to ongoing efforts to compute accurate stellar ages, we are able to characterise stars in different regions of the Milky Way. The Gaia and Kepler space-missions, along with ground-based spectroscopic surveys such as APOGEE, provide a unique way to study the chemo-kinematics relations as a function of age through the Galactic stella…
Identification of pre-stellar cores in high-mass star forming clumps via H2D+ observations with ALMA
Wyrowski, F.; Caselli, P.; Giannetti, A. +5 more
Context. The different theoretical models concerning the formation of high-mass stars make distinct predictions regarding their progenitors, which are the high-mass pre-stellar cores. However, no conclusive observation of such objects has been made to date.
Aims: We aim to study the very early stages of high-mass star formation in two infrare…
The properties of dwarf spheroidal galaxies in the Cen A group. Stellar populations, internal dynamics, and a heart-shaped Hα ring
Coccato, Lodovico; Fahrion, Katja; Müller, Oliver +7 more
Dwarf spheroidal galaxies (dSphs) have been extensively investigated in the Local Group, but their low luminosity and surface brightness make similar work in more distant galaxy groups challenging. Modern instrumentation unlocks the possibility of scrutinizing these faint systems in other environments, expanding the parameter space of group proper…
ALMA 870 µm continuum observations of HD 100546. Evidence of a giant planet on a wide orbit
Lodato, G.; Fedele, D.; Maud, L. +1 more
This paper reports on a new analysis of archival ALMA 870 µm dust continuum observations. Along with the previously observed bright inner ring (r ~ 20-40 au), two addition substructures are evident in the new continuum image: a wide dust gap, r ~ 40-150 au, and a faint outer ring ranging from r ~ 150 au to r ~ 250 au and whose presence was f…
A homogeneous spectroscopic analysis of a Kepler legacy sample of dwarfs for gravity-mode asteroseismology
Li, Gang; Rix, Hans-Walter; Bowman, Dominic M. +12 more
Context. Asteroseismic modelling of the internal structure of main-sequence stars born with a convective core has so far been based on homogeneous analyses of space photometric Kepler light curves of four years in duration, to which most often incomplete inhomogeneously-deduced spectroscopic information was added to break degeneracies.
Aims: …
Whistler waves observed by Solar Orbiter/RPW between 0.5 AU and 1 AU
Maksimovic, M.; Bale, S. D.; Chust, T. +29 more
Context. Solar wind evolution differs from a simple radial expansion, while wave-particle interactions are assumed to be the major cause for the observed dynamics of the electron distribution function. In particular, whistler waves are thought to inhibit the electron heat flux and ensure the diffusion of the field-aligned energetic electrons (Stra…
PSP/IS⊙IS observations of the 29 November 2020 solar energetic particle event
Mitchell, D. G.; McComas, D. J.; Bale, S. D. +24 more
Aims: On 29 November 2020, at 12:34 UT, active region 12790 erupted with an M4.4 class flare and a 1700 km s−1 coronal mass ejection. Parker Solar Probe (PSP) was completing its seventh orbit around the Sun and was located at 0.8 au when the Integrated Science Investigation of the Sun (IS⊙IS) measured the ensuing mid-sized solar en…
Modeling the mixed-morphology supernova remnant IC 443. Origins of its complex morphology and X-ray emission
Miceli, M.; Bocchino, F.; Orlando, S. +4 more
Context. The morphology and the distribution of material observed in supernova remnants (SNRs) reflect the interaction of the supernova (SN) blast wave with the ambient environment, the physical processes associated with the SN explosion, and the internal structure of the progenitor star. IC 443 is a mixed-morphology (MM) SNR located in a quite co…
STIX X-ray microflare observations during the Solar Orbiter commissioning phase
Massa, Paolo; Krucker, Säm; Piana, Michele +34 more
Context. The Spectrometer/Telescope for Imaging X-rays (STIX) is the hard X-ray instrument onboard Solar Orbiter designed to observe solar flares over a broad range of flare sizes.
Aims: We report the first STIX observations of solar microflares recorded during the instrument commissioning phase in order to investigate the STIX performance at…