Search Publications
Constraining quasar structure using high-frequency microlensing variations and continuum reverberation
Courbin, F.; Sluse, D.; Millon, M. +4 more
Gravitational microlensing is a powerful tool for probing the inner structure of strongly lensed quasars and for constraining parameters of the stellar mass function of lens galaxies. This is achieved by analysing microlensing light curves between the multiple images of strongly lensed quasars and accounting for the effects of three main variable …
H2CS deuteration maps towards the pre-stellar core L1544
Eisenhauer, F.; Fuente, A.; Caselli, P. +7 more
Context. Deuteration is a crucial tool for understanding the complexity of interstellar chemical processes, especially when they involve the interplay of gas-phase and grain-surface chemistry. In the case of multiple deuteration, comparing observation with the results of chemical modelling is particularly effective to study how molecules are inher…
CoBiToM Project - II. Evolution of contact binary systems close to the orbital period cut-off
Hatzidimitriou, D.; Hakala, P.; Liakos, A. +7 more
Ultra-short orbital period contact binaries (Porb < 0.26 d) host some of the smallest and least massive stars. These systems are faint and rare, and it is believed that they have reached a contact configuration after several Gyrs of evolution via angular momentum loss, mass transfer, and mass loss through stellar wind processes. This…
Validation and Improvement of the Pan-STARRS Photometric Calibration with the Stellar Color Regression Method
Yuan, Haibo; Xiao, Kai
As one of the best ground-based photometric data set, Pan-STARRS1 (PS1) has been widely used as the reference to calibrate other surveys. In this work, we present an independent validation and recalibration of the PS1 photometry using spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR7, and photometri…
Compact object candidates with K/M-dwarf companions from LAMOST low-resolution survey
Gu, Wei-Min; Sou, Hao; Yi, Tuan +6 more
Searching for compact objects (black holes, neutron stars, or white dwarfs) in the Milky Way is essential for understanding the stellar evolution history, the physics of compact objects, and the structure of our Galaxy. Compact objects in binaries with a luminous stellar companion are perfect targets for optical observations. Candidate compact obj…
Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves. II. Period-Fourier-Metallicity Relations for First Overtone RR Lyrae
Dall'Ora, Massimo; Bono, Giuseppe; Fiorentino, Giuliana +11 more
We present new period-ϕ 31-[Fe/H] relations for first-overtone RRL stars (RRc), calibrated over a broad range of metallicities (-2.5 ≲ [Fe/H] ≲ 0.0) using the largest currently available set of Galactic halo field RRL with homogeneous spectroscopic metallicities. Our relations are defined in the optical (ASAS-SN V band) and, inaugurally…
The dawn of a new era for dustless HdC stars with Gaia eDR3
Kasliwal, M. M.; Karambelkar, V.; Tisserand, P. +7 more
Context. Decades after their discovery, only four hydrogen-deficient carbon (HdC) stars were known to have no circumstellar dust shell. This is in complete contrast to the ∼130 known Galactic HdC stars that are notorious for being heavy dust producers, that is the R Coronae Borealis (RCB) stars. Together, they form a rare class of supergiant stars…
The Planetary Theory of Solar Activity Variability: A Review
Scafetta, Nicola; Bianchini, Antonio
Commenting the 11-year sunspot cycle, Wolf (1859, MNRAS 19, 85–86) conjectured that "the variations of spot-frequency depend on the influences of Venus, Earth, Jupiter, and Saturn." The high synchronization of our planetary system is already nicely revealed by the fact that the ratios of the planetary orbital radii are closely related to each othe…
Massive Compact Dust Disk with a Gap around CW Tau Revealed by ALMA Multiband Observations
Kataoka, Akimasa; Tsukagoshi, Takashi; Ueda, Takahiro
Compact protoplanetary disks with a radius of ≲50 au are common around young low-mass stars. We report high-resolution ALMA dust continuum observations toward a compact disk around CW Tau at Bands 4 (λ = 2.2 mm), 6 (1.3 mm), 7 (0.89 mm), and 8 (0.75 mm). The spectral energy distribution shows the spectral slope of 2.0 ± 0.24 between 0.75 and 1.3 m…
A Mirage or an Oasis? Water Vapor in the Atmosphere of the Warm Neptune TOI-674 b
Fortney, Jonathan J.; Mikal-Evans, Thomas; Lothringer, Joshua D. +14 more
We report observations of the recently discovered warm Neptune TOI-674 b (5.25 R ⊕, 23.6 M ⊕) with the Hubble Space Telescope's Wide Field Camera 3 instrument. TOI-674 b is in the Neptune desert, an observed paucity of Neptune-size exoplanets at short orbital periods. Planets in the desert are thought to have complex evolutio…