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A bunch of exoplanets characterized with data from HARPS-N at TNG

Kepler_all_planets.jpg: Artist's view for a 'bunch of exoplanets'.Credits: NASA/W. Stenzel

Kepler-1655b is a sub Neptune size planet transiting a star similar to our Sun. Thanks to the analysis from Kepler observations, combined with high-resolution spectra from HARPS-N, it was possible to determine an orbital period of nearly 12 days, a radius a bit larger than 2 times the Earth radii (Re) and a mass of about 5 Earth masses (Me).

Densities of transiting planets may be derived from the measured radius through its light curve, (as it passes in front of the host star) and its mass, due to radial velocity variations measured by high resolution spectra. In this case, it was possible to establish that Kepler-1655b lies in the boundary of rocky and gas-rich planets. Link to the paper: http://adsabs.harvard.edu/abs/2018AJ....155..203H

Analysis from HARPS-N data at TNG, combined with archival data from HIRES at the Keck telescope, lead to the discovery of a sub-jovian mass planet, with the longest period known up-to-date. Through the radial velocity data set spanning about 20 years of observations it was possible to refine the orbital solution for the 11.44 day period super Earth Gl15A b, with mass Msin(i) = 3 Me. It also revealed the signal of a planetary companion with a Keplerian orbit, period about 21 years and super-Neptune mass of Msin(i) = 36 Me.

It also revealed the signal of a planetary companion with a Keplerian orbit, period about 21 years and super-Neptune mass of Msin(i) = 36 Me. The star hosting this planet: Gl15A has a companion Gl15B, and is the stellar binary system closest to our Solar System at a distance of 3.57 pc. Applying numerical methods for dynamical analysis, the presence of Gl15B is strongly determinant in the characteristic of the planetary system observed. Its orbital architecture constitutes a very important laboratory for the investigation of formation and orbital evolution scenarios for planetary systems in binary stellar systems. Link to the paper: http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1804.03476

Other exoplanets have been investigated with HARPS-N after their discovery by the Kepler mission in the K2 configuration.

A warm Saturn-sized planet is transiting HD 89345, a slightly evolved star. radial velocity measurements from HARPS-N data (among other instruments) allowed the characterization of the planetary parameters, namely: the orbital period of 11.8 days, the planet radius of around 6.9 times Re and a mass of around 36 times the Me. Moreover, asteroseismology made possible to determine the stellar mass and radius, 1.12 solar masses and 1.6 solar radii respectively. The analysis of the solar-like oscillations indicates that the stars has recently left the main sequence, based on the inferred age of 9.4 Gyr. Link to the paper: http://adsabs.harvard.edu/abs/2018MNRAS.478.4866V

Analysis from HARPS-N data at TNG, combined with archival data from HIRES at the Keck telescope, lead to the discovery of a sub-jovian mass planet, with the longest period known up-to-date. Through the radial velocity data set spanning about 20 years of observations it was possible to refine the orbital solution for the 11.44 day period super Earth Gl15A b, with mass Msin(i) = 3 Me. It also revealed the signal of a planetary companion with a Keplerian orbit, period about 21 years and super-Neptune mass of Msin(i) = 36 Me.

The star hosting this planet: Gl15A has a companion Gl15B, and is the stellar binary system closest to our Solar System at a distance of 3.57 pc. Applying numerical methods for dynamical analysis, the presence of Gl15B is strongly determinant in the characteristic of the planetary system observed. Its orbital architecture constitutes a very important laboratory for the investigation of formation and orbital evolution scenarios for planetary systems in binary stellar systems. Link to the paper: http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1804.03476

Other exoplanets have been investigated with HARPS-N after their discovery by the Kepler mission in the K2 configuration.

A warm Saturn-sized planet is transiting HD 89345, a slightly evolved star. radial velocity measurements from HARPS-N data (among other instruments) allowed the characterization of the planetary parameters, namely: the orbital period of 11.8 days, the planet radius of around 6.9 times Re and a mass of around 36 times the Me. Moreover, asteroseismology made possible to determine the stellar mass and radius, 1.12 solar masses and 1.6 solar radii respectively. The analysis of the solar-like oscillations indicates that the stars has recently left the main sequence, based on the inferred age of 9.4 Gyr. Link to the paper: http://adsabs.harvard.edu/abs/2018MNRAS.478.4866V

HARPS-N (among other instruments) helped to determine a Super-Earth companion around K2-216, a moderately active K5V star. The new planet discovered, K2-216b, has an upper limit mass of eight Me, a radius of 1.75 times Re and an orbital period of 2.17 days. The density is consistent with a rocky composition of primarily iron and magnesium silicate. It is a remnant core, stripped of its atmosphere, and is one of the largest planets found that has lost its atmosphere. Link to the paper: http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1805.04774

K2-260 b is a hot Jupiter transiting a spectral type F star. It has an orbital period of 2.6 days, mass of 1.4 Jupiter masses (Mj) and radius of 1.5 Jupiter radii (Rj). K2-261 b is a warm Saturn around a bright spectral type G star. It has an orbital period of 11.6 days, mass of 0.2 Mj, radius of 0.8 Rj and it has an eccentric orbit of e = 0.4. Link to the paper: http://adsabs.harvard.edu/abs/2018MNRAS.tmp.2121J

GJ 9827 hosts the nearest planetary system at 30 pc. It represents one of the very few systems where the dynamical evolution and the atmospheric escape can be studied in detail for all planets, helping us to understand how compact systems form and evolve. The three exoplanets are:

  • GJ 9827b with orbital period 1.2 days, mass 3.7 Me, radius 1.6 Re with rocky nucleus.
  • GJ 9827c with orbital period 3.6 days, mass 1.5 Me, radius 1.3 Re with rocky nucleus.
  • GJ 9827d with orbital period 6.2 days, mass 2.4 Me, radius 2.1 Re with rocky nucleus and a large gaseous envelope.
Link to the paper: http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1802.09557

A group of 44 planetary candidates was confirmed and characterized thanks to HARSP-N data. The group of planets lie in the categories of super Earths with radii between 1 and 2 Re, sub Neptunes with radii between 2 and 4 Re and sub Saturns with radii between 4 and 8 Re. Link to the paper: http://adsabs.harvard.edu/abs/2018AJ....156...78L

Mass-radius diagram of all small exoplanets (Rp ≤ 2 REarth, and Mp ≤ 30 MEarth) with a measured mass and radius to a precision better than 20% as listed in the NASA Exoplanet Archive. Earth and Venus are plotted in red filled circles for comparison. The solid lines are theoretical mass-radius curves (Zeng et al. 2016), from top to bottom: 100% H2O (blue solid line), a mixture of 50% H2O and 50% MgSiO3 (cyan dashed line), 100% MgSiO3 (green solid line), a mixture of 75 % MgSiO3 and 25% Fe (magenta dashed line), a mixture of 50% MgSiO3 and 50% Fe (brown solid line), a mixture of 25 % MgSiO3 and 75 % Fe (red dashed line), and 100% Fe (orange solid line). Credits: https://arxiv.org/pdf/1805.04774.pdf