M. Pedani

Characterizing K2 Planet Discoveries: A Super-Earth Transiting the Bright K Dwarf HIP 116454

We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1 dwarf with high proper motion and a parallax-based distance of 55.2 ± 5.4 pc. Based on high-resolution optical spectroscopy, we find that the host star is metal-poor with (Fe/H) =− 0.16 ± 0.08 and has a radius R� = 0.716 ± 0.024 Rand mass M� = 0.775 ± 0.027 M� . The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in 2014 February. During the 9 days of observations, K2 observed a single transit event. Using a new K2 photometric analysis technique, we are able to correct small telescope drifts and recover the observed transit at high confidence, corresponding to a planetary radius of Rp = 2.53 ± 0.18 R⊕. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 ± 1.33 M⊕ planet in a 9.1 day orbit, consistent with the transit depth, duration, and ephemeris. Follow-up photometric measurements from the MOST satellite confirm the transit observed in the K2 photometry and provide a refined ephemeris, making HIP 116454 b amenable for future follow-up observations of this latest addition to the growing population of transiting super-Earths around nearby, bright stars.

Extreme gas properties in the most distant quasars

We present near-IR, low resolution spectra of eight of the most distant quasars known, with redshifts in the range 4.9 < z < 6.4. Half of these quasars are characterized by deep, broad and blueshifted absorption features associated with both high and low ionization species (CIV, SiIV, AlIII, MgII), i.e. they belong to the class of Broad Absorption Line (BAL) quasars, which are associated with powerful outflows of dense gas. Although the sample is small, the large fraction of BAL quasars, the depth and ionization state of the absorption features suggest that these most distant quasars are surrounded by a much larger amount of dense gas than lower redshift (z < 4) quasars. The possible interpretation in terms of extremely high accretion rates and the association with the early formation of quasars and of their host galaxies is discussed. The absorption properties of the dust, associated with the gas along the line of sight, appear different with respect to lower redshift quasars, possibly indicating different dust physics at these highest redshifts.

The GAPS programme with HARPS-N at TNG - XI. Pr 0211 in M 44: the first multi-planet system in an open cluster

Open cluster (OC) stars share the same age and metallicity, and, in general, their age and mass can be estimated with higher precision than for field stars. For this reason, OCs are considered an important laboratory to study the relation between the physical properties of the planets and those of their host stars, and the evolution of planetary systems. We started an observational campaign within the GAPS collaboration to search for and characterize planets in OCs We monitored the Praesepe member Pr0211 to improve the eccentricity of the Hot-Jupiter (HJ) already known to orbit this star and search for additional planets. An eccentric orbit for the HJ would support a planet-planet scattering process after its formation. From 2012 to 2015, we collected 70 radial velocity (RV) measurements with HARPS-N and 36 with TRES of Pr0211. Simultaneous photometric observations were carried out with the robotic STELLA telescope in order to characterize the stellar activity. We discovered a long-term trend in the RV residuals that we show to be due to the presence of a second, massive, outer planet. Orbital parameters for the two planets are derived by simultaneously fitting RVs and photometric light curves, with the activity signal modelled as a series of sinusoids at the rotational period of the star and its harmonics. We confirm that Pr0211b has a nearly circular orbit (

The GAPS programme with HARPS-N at TNG - V. A comprehensive analysis of the XO-2 stellar and planetary systems

e = 0.02 \pm 0.01

On the efficiency of the Ultra Steep Spectrum technique in finding high-z radiogalaxies

), with an improvement of a factor two with respect to the previous determination of its eccentricity, and estimate that Pr0211c has a mass

Light pollution at the Roque de los Muchachos Observatory

M_p\sin i = 7.9 \pm 0.2 M_J

The GIANO spectrometer: towards its first light at the TNG

, a period

The GAPS programme with HARPS-N at TNG - VI. The curious case of TrES-4b

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Lines and continuum sky emission in the near infrared: observational constraints from deep high spectral resolution spectra with GIANO-TNG

3500 days and a very eccentric orbit (

HADES RV Programme with HARPS-N at TNG - V. A super-Earth on the inner edge of the habitable zone of the nearby M dwarf GJ 625

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