Search Publications
A photometric in-depth look at the core-collapsed globular cluster NGC 6284
Cadelano, Mario; Pallanca, Cristina; Dalessandro, Emanuele +4 more
High-resolution Hubble Space Telescope (HST) optical observations have been used to perform the deepest photometric study of the poorly studied Galactic globular cluster NGC 6284. The deep colour-magnitude diagram (CMD) that we obtained reaches 6 mag below the main-sequence turnoff. We provide the first determination of the gravitational centre (C…
Investigating the long secondary period phenomenon with the ASAS-SN and Gaia data
Pawlak, Michał; Mowlavi, Nami; Eyer, Laurent +1 more
Aims: The aim of this work is to create a complete list of sources exhibiting a long secondary period (LSP) in the ASAS-SN catalog of variable stars, and analyze the properties of this sample compared to other long period variables without an LSP.
Methods: We used the period-amplitude diagram to identify the 55 572 stars showing an LSP, …
Indications of an offset merger in Abell 3667
Okabe, N.; Simionescu, A.; Fujita, Y. +13 more
Context. Cluster mergers are the most energetic events, releasing kinetic energies of up to 1064 erg and involving megaparsec(Mpc)-scale shocks in their intra-cluster medium (ICM). In merging clusters, cold fronts are frequently observed, which are characterized by temperature and density jumps while maintaining constant pressure. They,…
Discovery of two warm mini-Neptunes with contrasting densities orbiting the young K3V star TOI-815
Helling, Christiane; Hellier, Coel; Charnoz, Sébastien +130 more
We present the discovery and characterization of two warm mini-Neptunes transiting the K3V star TOI-815 in a K–M binary system. Analysis of its spectra and rotation period reveal the star to be young, with an age of 200‑200+400 Myr. TOI-8l5b has a 11.2-day period and a radius of 2.94 ± 0.05 R⊕ with transits observe…
NGTS-30b/TOI-4862b: An 1 Gyr old 98-day transiting warm Jupiter
Bouchy, F.; Alves, D. R.; Henning, T. +63 more
Context. Long-period transiting exoplanets bridge the gap between the bulk of transit- and Doppler-based exoplanet discoveries, providing key insights into the formation and evolution of planetary systems. The wider separation between these planets and their host stars results in the exoplanets typically experiencing less radiation from their host…
Spatially correlated stellar accretion in the Lupus star-forming region: Evidence for ongoing infall from the interstellar medium
Benisty, Myriam; Manara, Carlo F.; Gupta, Aashish +1 more
Context. Growing evidence suggests that protoplanetary discs may be influenced by late stage infall from the interstellar medium (ISM). It remains unclear the degree to which infall shapes disc populations at ages ≳1 Myr. Aims. We explored possible spatial correlations between stellar accretion rates in the Lupus star-forming region, which would s…
Three super-Earths and a possible water world from TESS and ESPRESSO
Bouchy, F.; Rebolo, R.; Allende Prieto, C. +52 more
Context. Since 2018, the ESPRESSO spectrograph at the VLT has been hunting for planets in the southern skies via the radial velocity (RV) method. One of its goals is to follow up on candidate planets from transit surveys such as the TESS mission, with a particular focus on small planets for which ESPRESSO's RV precision is vital.
Aims: We aim…
Simultaneous NICER and NuSTAR observations of the ultraluminous source NGC 4190 ULX-1
Martí, Josep; García, Federico; Fogantini, Federico A. +6 more
Aims: We present an X-ray analysis of three different XMM-Newton observations together with simultaneous NICER and NuSTAR observations of the ultraluminous X-ray source NGC 4190 ULX-1. Our goal is to constrain the structure of the accretion disk and the geometrical properties of the source.
Methods: We performed temporal and spectral ana…
The origin of the soft excess in the luminous quasar HE 1029-1401
Bianchi, S.; Piconcelli, E.; Matt, G. +7 more
The enigmatic and intriguing phenomenon of the "soft excess" observed in the X-ray spectra of luminous quasars continues to be a subject of considerable interest and debate in the field of high-energy astrophysics. This study focuses on the quasar HE 1029-1401 (z = 0.086, log(Lbol/[erg s‑1]) = 46.0 ± 0.2), with a particular e…
Unveiling the origin of the optical and UV emission during the 2017 giant outburst of the Galactic ULX pulsar Swift J0243.6+6124
Mas-Hesse, J. M.; van den Eijnden, J.; Reig, P. +8 more
Context. From late September 2017 to January 2018, the Be X-ray binary (BeXB) Swift J0243.6+6124 underwent a giant outburst that was unprecedently bright. The reported X-ray luminosities were so high that the system was classified as an ultraluminous X-ray source (ULX). It was also the first BeXB pulsar to show radio jet emission. The source was n…