Related papers: Planetary system around Vega
A key item of interest for planetary scientists and astronomers is the habitable zone, or the distance from a host star where a terrestrial planet can maintain necessary temperatures in order to retain liquid water on its surface. However,…
(Abridged) A numerical model of a circumstellar debris disk is developed and applied to observations of the circumstellar dust orbiting beta Pictoris. The model accounts for the rates at which dust is produced by collisions among unseen…
In a recent paper (Crida et al. 2018, accepted on April 19), we presented a method to derive the mass and radius of a transiting exoplanet and their intrinsic correlation, that we applied to 55 Cnc e. We wrote: "More precise observations of…
T Cha is a young star surrounded by a transitional disk with signatures of planet formation. We have obtained high-resolution and high-sensitivity ALMA observations of T Cha in the ${\rm CO}(3$--$2)$, ${\rm ^{13}CO}(3$--$2)$, and ${\rm…
Searches for young gas giant planets at wide separations have so far focused on techniques appropriate for compact (Jupiter sized) planets. Here we point out that protoplanets born through Gravitational Instability (GI) may remain in an…
Dark rings with bright rims are the indirect signposts of planets embedded in protoplanetary discs. In a recent first, an azimuthally elongated AU-scale blob, possibly a planet, was resolved with ALMA in TW Hya. The blob is at the edge of a…
With hundreds of exoplanets detected, it is necessary to revisit giant planets accretion models to explain their mass distribution. In particular, formation of sub-jovian planets remains unclear, given the short timescale for the runaway…
We present VLA and ALMA observations of the close (0.3" = 90 au separation) protobinary system SVS 13. We detect two small circumstellar disks (radii $\sim$12 and $\sim$9 au in dust, and $\sim$30 au in gas) with masses of $\sim$0.004-0.009…
Fundamental properties of the planet Venus, such as its internal mass distribution and variations in length of day, have remained unknown. We used Earth-based observations of radar speckles tied to the rotation of Venus obtained in…
The plausibility of an unseen planet in the outer solar system, and the expected orbit and mass of such a planet, have long been a topic of inquiry and debate. We calculate the long-term orbital stability of distant TNOs, which allows us to…
(abbreviated) We aim to study the inner wind of the well-known AGB star CW Leo. Different diagnostics probing different geometrical scales have pointed toward a non-homogeneous mass-loss process: dust clumps are observed at milli-arcsec…
The debris disk surrounding the young star TWA 7 exhibits morphological features that tightly constrain its planetary architecture. JWST/MIRI observations have recently revealed a directly imaged outer planet at large separation. The disk…
High resolution ALMA observations revealed a variety of rich substructures in numerous protoplanetary disks. These structures consist of rings, gaps and asymmetric features. It is debated whether planets can be accounted for these…
At the cloud top level of Venus (65-70 km altitude) the atmosphere rotates 60 times faster than the underlying surface, a phenomenon known as superrotation. Whereas on Venus's dayside the cloud top motions are well determined and Venus…
Dusty discs detected around main-sequence stars are thought to be signs of planetesimal belts in which the dust distribution is shaped by collisional and dynamical processes, including interactions with gas if present. The debris disc…
We have carried out a sensitive search for gas emission lines at infrared and millimeter wavelengths for a sample of 15 young sun-like stars selected from our dust disk survey with the Spitzer Space Telescope. We have used mid-infrared…
From existing broad-band images obtained with the Hubble Space Telescope, we located 92 globules, for which we derived positions, dimensions, orientations, extinctions, masses, proper motions, and their distributions. The globules have mean…
We have imaged the disc of the young star HL Tau using the VLA at 1.3 cm, with 0.08" resolution (as small as the orbit of Jupiter). The disc is around half the stellar mass, assuming a canonical gas-mass conversion from the measured mass in…
We present new observations of CO J=2-1 emission from the protoplanetary disk around TW Hya. Emission is detected out to 240 au (4") and found to exhibit azimuthal variations up to 20% beyond 180 au (3"), with the west side of the disk…
Direct imaging observations constrain the fraction of stars orbited by gas giant planets with separations greater than 10 au to about 0.01 only. This is widely believed to indicate that massive protoplanetary discs rarely fragment on…