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Mottola S.,German Aerospace Center | Di Martino M.,National institute for astrophysics | Erikson A.,German Aerospace Center | Gonano-Beurer M.,German Aerospace Center | And 7 more authors.
Astronomical Journal | Year: 2011

We present the results of a Jupiter Trojans' light curve survey aimed at characterizing the rotational properties of Trojans in the approximate size range 60-150km. The survey, which was designed to provide reliable and unbiased estimates of rotation periods and amplitudes, resulted in light curves for a total of 80 objects, 56 of which represent the first determinations published to date and nine of which supersede previously published erroneous values. Our results more than double the size of the existing database of rotational properties of Jovian Trojans in the selected size range. The analysis of the distributions of the rotation periods and light curve amplitudes is the subject of companion papers. © 2011. The American Astronomical Society. All rights reserved. Source


Sozzetti A.,National institute for astrophysics | Bernagozzi A.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Bertolini E.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Calcidese P.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | And 11 more authors.
EPJ Web of Conferences | Year: 2013

First, we summarize the four-year long efforts undertaken to build the final setup of the APACHE Project, a photometric transit search for small-size planets orbiting bright, low-mass M dwarfs. Next, we describe the present status of the APACHE survey, officially started in July 2012 at the site of the Astronomical Observatory of the Autonomous Region of the Aosta Valley, in the Western Italian Alps. Finally, we briefly discuss the potentially far-reaching consequences of a multi-technique characterization program of the (potentially planet-bearing) APACHE targets. © Owned by the authors, published by EDP Sciences, 2013. Source


Christille J.-M.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Christille J.-M.,University of Perugia | Bernagozzi A.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Bertolini E.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | And 13 more authors.
EPJ Web of Conferences | Year: 2013

Small-size ground-based telescopes can effectively be used to look for transiting rocky planets around nearby low-mass M stars using the photometric transit method, as recently demonstrated for example by the MEarth project. Since 2008 at the Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA), we have been preparing for the long-term photometric survey APACHE, aimed at finding transiting small-size planets around thousands of nearby early and mid-M dwarfs. APACHE (A PAthway toward the Characterization of Habitable Earths) is designed to use an array of five dedicated and identical 40-cm Ritchey-Chretien telescopes and its observations started at the beginning of summer 2012. The main characteristics of the survey final set up and the preliminary results from the first weeks of observations will be discussed. © Owned by the authors, published by EDP Sciences, 2013. Source


Damasso M.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Damasso M.,University of Padua | Giacobbe P.,University of Trieste | Calcidese P.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | And 5 more authors.
Publications of the Astronomical Society of the Pacific | Year: 2010

We present the results of a site characterization study carried out at the Astronomical Observatory of the Autonomous Region of the Aosta Valley (OAVdA), in the western Italian Alps, aimed at establishing its potential to host a photometric transit search for small-size planets around a statistically significant sample of nearby cool M dwarfs. For the purpose of the site testing campaign, we gathered photometric and seeing measurements utilizing different instruments available at the site. As in any search for new locations for astronomical observations, we gauged site-dependent observing conditions such as night-sky brightness, photometric precision, and seeing properties. Public meteorological data were also used in order to help in the determination of the actual number of useful observing nights per year. The measured zenithal V-band night-sky brightness is typical of that of very good, very dark observing sites. The extinction registered at the V-band is not dissimilar from that of other sites. The median seeing over the period of in situ observations is found to be ∼1.7″. Given the limited duration of the observations, we did not probe any possible seeing seasonal patterns or the details of its possible dependence on other meteorological parameters, such as wind speed and direction. Moreover, our data show that the seeing at the observatory was reasonably stable during most of the nights. The fraction of fully clear nights per year amounts to 39%, while the total of useful nights increases to 57%, assuming a (conservative) cloud cover of not more than 50% of the night. Based on the analysis of photometric data collected over the period of 2009 May-August for three stellar fields centered on the transiting planet hosts WASP-3, HAT-P-7, and Gliese 436, we achieve seeing-independent best-case photometric precision σ ph ≤3 mmag (rms) in several nights for bright stars (R ≤ 11 mag). A median performance σ ph-6 mmag during the observing period is obtained for stars with R ≤ 13 mag. A by-product of the significant amount of photometric data collected in the stellar fields of WASP-3 and HAT-P-7 was the identification of a handful of new variable stars, four of which are presented and discussed here. Our results demonstrate that the OAVdA site is well poised to conduct an upcoming long-term photometric survey for transiting low-mass, small-size planets around a well-defined sample of M dwarfs in the solar neighborhood. © 2010. The Astronomical Society of the Pacific. All rights reserved. Source


Damasso M.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Damasso M.,University of Padua | Bernagozzi A.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | Bertolini E.,Astronomical Observatory of the Autonomous Region of the Aosta Valley | And 7 more authors.
Proceedings of the International Astronomical Union | Year: 2010

Small ground-based telescopes can effectively be used to look for transiting rocky planets around nearby low-mass M stars, as recently demonstrated for example by the MEarth project. Since December 2009 at the Astronomical Observatory of the Autonomous Region of Aosta Valley (OAVdA) we are monitoring photometrically a sample of red dwarfs with accurate parallax measurements. The primary goal of this 'pilot study' is the characterization of the photometric microvariability of each target over a typical period of approximately 2 months. This is the preparatory step to long-term survey with an array of identical small telescopes, with kick-off in early 2011. Here we discuss the present status of the study, describing the stellar sample, and presenting the most interesting results obtained so far, including the aggressive data analysis devoted to the characterization of the variability properties of the sample and the search for transit-like signals. © 2011 International Astronomical Union. Source

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