Search Publications
Three-Dimensional Venus Cloud Structure Simulated by a General Circulation Model
Shao, Wencheng D.; Dai, Longkang; Mendonça, João. M.
The clouds have a great impact on Venus's energy budget and climate evolution, but its three-dimensional structure is still not well understood. Here we incorporate a simple Venus cloud physics scheme into a flexible GCM to investigate the three-dimensional cloud spatial variability. Our simulations show good agreement with observations in terms o…
The true nature of HE 0057-5959, the most metal-poor, Li-rich star
Salaris, M.; Bonifacio, P.; Monaco, L. +2 more
The Li-rich stars are a class of rare objects with a surface lithium abundance, A(Li), that exceeds that of other stars in the same evolutionary stage. The origin of these stars is still debated, and valuable routes to look at include the Cameron-Fowler mechanism, a mass-transfer process in a binary system, or the engulfment of rocky planets or br…
Identifying Plasma Fractionation Processes in the Chromosphere Using IRIS
Stangalini, Marco; Long, David M.; Testa, Paola +7 more
The composition of the solar corona differs from that of the photosphere, with the plasma thought to fractionate in the solar chromosphere according to the first ionization potential (FIP) of the different elements. This produces a FIP bias, wherein elements with a low FIP are preferentially enhanced in the corona compared to their photospheric ab…
Radial velocity homogeneous analysis of M dwarfs observed with HARPS: I. Exoplanet detection and candidates
Bouchy, F.; Meunier, N.; Unger, N. +12 more
Context. The census of planets around M dwarfs in the solar neighbourhood meets two challenges: detecting the best targets for the future characterisation of planets with ELTs, and studying the statistics of planet occurrence that are crucial to formation scenarios. The radial velocity (RV) method remains the most appropriate for such a census as …
The Star Formation History of Nearby Galaxies: A Machine Learning Approach
Tian, Hao; Yang, Ming; Liu, Chao +2 more
Reproducing color–magnitude diagrams (CMDs) of star-resolved galaxies is one of the most precise methods for measuring the star formation history (SFH) of nearby galaxies back to the earliest time. The upcoming big data era poses challenges to the traditional numerical technique in its capacity to deal with vast amounts of data, which motivates us…
Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b
Alonso, R.; Deleuil, M.; Erikson, A. +86 more
Context. Hot Jupiters (HJs) with close-by planetary companions are rare, with only a handful of them having been discovered so far. This could be due to their suggested dynamical histories, which lead to the possible ejection of other planets. TOI-2109 b is special in this regard because it is the HJ with the closest relative separation from its h…
Exploring Unobscured Quasi-stellar Objects in the Southern Hemisphere with KS4
Im, Myungshin; Kim, Minjin; Song, Hyunmi +7 more
We present a catalog of unobscured quasi-stellar object (QSO) candidates in the Southern Hemisphere from the early interim data of the KMTNet Synoptic Survey of Southern Sky (KS4). The KS4 data covers ∼2500 deg2 sky area, reaching 5σ detection limits of ∼22.1–22.7 AB mag in the BVRI bands. Combining this with available infrared photomet…
New gravity field of comet 67P/C-G based on Rosetta's Doppler and optical data
Marty, Jean-Charles; Jorda, Laurent; Le Maistre, Sebastien +3 more
The gravity field of a celestial body gives valuable insights into its fundamental properties such as its density and internal structure. The Doppler data collected by the Radio-Science Investigation (RSI) experiment of the Rosetta mission were previously used to determine the gravity field of comet 67P/Churyumov–Gerasimenko up to degree 2 (Pätzol…
H2 molecular gas in the old planetary nebula NGC 3587
Guerrero, M. A.; Toalá, J. A.; Ramos-Larios, G. +2 more
The acquisition of high-quality deep images of planetary nebulae (PNe) has allowed the detection of a wealth of small-scale features, which highlight the complexity of the formation history and physical processes shaping PNe. Here we present the discovery of three groups of clumps embedded within the nebular shell of the evolved PN NGC 3587, the O…
Triple trouble with PSR J1618‑3921: Mass measurements and orbital dynamics of an eccentric millisecond pulsar
Guillemot, L.; Possenti, A.; Kramer, M. +11 more
Context. PSR J1618‑3921 is one of five known millisecond pulsars (MSPs) in eccentric orbits (eMPSs) located in the Galactic plane, whose formation is poorly understood. Earlier studies of these objects revealed significant discrepancies between observations and predictions from standard binary evolution scenarios of pulsar-helium white dwarf (HeWD…