Search Publications
A benchmark white dwarf-ultracool dwarf wide field binary
Smith, Leigh C.; Minniti, Dante; Caceres, Claudio +8 more
We present the discovery and multiwavelength characterization of VVV J1438-6158 AB, a new field wide-binary system consisting of a $4.6^{+5.5}_{-2.4}~{\rm Gyr}$ and $T_{\rm eff} = 9500\pm 125~\mathrm{ K}$ DA white dwarf (WD) and a $T_{\rm eff} = 2400\pm 50~\mathrm{ K}$ M8 ultracool dwarf (UCD). The projected separation of the system is $a = 1236.7…
The Orbit and Mass of the Cepheid AW Per
Mérand, Antoine; Lanthermann, Cyprien; Anugu, Narsireddy +17 more
The Cepheid AW Per is a component in a multiple system with a long-period orbit. The radial velocities of Griffin cover the 38 yr orbit well. An extensive program of interferometry with the Center for High Angular Resolution Astronomy array is reported here, from which the long-period orbit is determined. In addition, a Hubble Space Telescope high…
Two-process Model and Residual Abundance Analysis of the Milky Way Massive Satellites
Horta, Danny; Hayes, Christian R.; Beaton, Rachael L. +4 more
The "two-process model" is a promising technique for interpreting stellar chemical abundance data from large-scale surveys (e.g., the Sloan Digital Sky Survey IV/V and the Galactic Archeology with HERMES survey), enabling more quantitative empirical studies of differences in chemical enrichment history between galaxies without relying on detailed …
A Stellar Dynamical Mass Measurement of the Supermassive Black Hole in NGC 3258
Gebhardt, Karl; Gültekin, Kayhan; Nagar, Neil +2 more
We present a stellar dynamical mass measurement of the supermassive black hole in the elliptical (E1) galaxy NGC 3258. Our findings are based on integral field unit spectroscopy from the Multi Unit Spectroscopic Explorer (MUSE) observations in narrow-field mode with adaptive optics and the MUSE wide-field mode, from which we extract kinematic info…
The GAPS Programme at TNG. LI. Investigating the correlations between transiting system parameters and host chromospheric activity
Scandariato, G.; Pagano, I.; Fossati, L. +28 more
Context. Stellar activity is the most relevant types of astrophysical noise that affect the discovery and characterization of extrasolar planets. On the other hand, the amplitude of stellar activity could hint at an interaction between the star and a close-in giant planet. Progress has been made in recent years in understanding how to deal with st…
Classifying Optical (Out)bursts in Cataclysmic Variables: The Distinct Observational Characteristics of Dwarf Novae, Micronovae, Stellar Flares, and Magnetic Gating
Littlefield, Colin; Iłkiewicz, Krystian; Scaringi, Simone +5 more
Cataclysmic variables can experience short optical brightenings, which are commonly attributed to phenomena such as dwarf novae outbursts, micronovae, donor flares, or magnetic gating bursts. Since these events exhibit similar observational characteristics, their identification has often been ambiguous. In particular, magnetic gating bursts and mi…
TESS duotransit candidates from the Southern Ecliptic Hemisphere
Ramsay, Gavin; Wheatley, Peter J.; Bayliss, Daniel +20 more
Discovering transiting exoplanets with long orbital periods allows us to study warm and cool planetary systems with temperatures similar to the planets in our own Solar system. The Transiting Exoplanet Survey Satellite (TESS) mission has photometrically surveyed the entire Southern Ecliptic Hemisphere in Cycle 1 (2018 August-2019 July), Cycle 3 (2…
Probing the accretion geometry of the atoll source 4U 1702-429 in different spectral states with NICER, NuSTAR, and AstroSat
Homan, Jeroen; Banerjee, Srimanta
We perform a comprehensive spectral study of a carefully selected sample (total exposure ~50.5 ks) of NICER observations of the atoll neutron star low-mass X-ray binary 4U 1702-429. Our sample encompasses nearly all classical spectral states found within the NICER data set. We require two thermal emission components, originating from the accretion…
Surveys of clumps, cores, and condensations in Cygnus-X. Searching for circumstellar disks
Qiu, Keping; Cao, Yue; Yang, Kai +2 more
Context. Theories and models have suggested that circumstellar disks could channel material to the central protostar, and resist star formation feedback. Our current knowledge of the picture and role of disks around massive protostars is unclear because the observational evidence of these circumstellar disks is limited.
Aims: To investigate w…
Testing the asteroseismic estimates of stellar radii with surface brightness-colour relations and Gaia DR3 parallaxes: Red giants and red clump stars
Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G. +1 more
Aims. We compared stellar radii derived from asteroseismic scaling relations with those estimated using two independent surface brightness-colour relations (SBCRs) combined with Gaia DR3 parallaxes. Methods. We cross-matched asteroseismic and astrometric data for over 6400 red giant branch (RGB) and red clump (RC) stars from the APO-K2 catalogue w…