Padova University
Padova University
Astronomy Department
Physics & Astronomy Dep.
Asiago
Asiago Observatory
Padova Observatory
Padova Observatory

Exoplanets & Stellar Populations Group


UNIVERSITY OF PADOVA - DEPARTMENT OF PHYSICS AND ASTRONOMY "GALILEO GALILEI"
vicolo Osservatorio 3, 35122 Padova - Italy tel. +39.049.827.8211     fax. +39.049.827.8212
                                                                                       
SCHOOL OF SCIENCE
    Bachelor degree [D.M. 270/2004 (L-30 - Physics)] in:
      Astronomy [SC1160]
      • Astronomy 1 (SCM0014351) - Prof. G. Piotto, courses details here
      • Astronomy 2 (SCP4068136) - Prof. S. Ortolani, courses details here

      Physics [SC1158]
      • Physics of Planets (SCN1032625) - Prof. F. Marzari, courses details here
    Master degree [D.M. 270/2004 (LM-58 - Universe sciences)] in:
      Astronomy [SC1173/2010/001PD]
      • Fundamentals of Astronomy and Astrophysics (SCP6076197) - Dr. V. Nascimbeni, courses details here
      • General Astrophysics (mod. A) (SCP4067977) - Prof. S. Ortolani, courses details here
      • Laboratory of Astrophysics 2 (SC04120546) - Prof. G. Piotto, courses details here
      • Stellar Populations (SCN1032617, SCN1035992) - Prof. G. Carraro, courses details here
SCHOOL OF MEDICINE
    Single cycle degree [D.M. 270/2004 (LM-41 - Medicine)] in:
      Medicine & Surgery
      • [ME1726] Physics & Biophysics (MEP5071018) - Prof. G. Carraro, courses details here
      • [ME1728] Physics & Biophysics (MEP5071018) - Prof. F. Marzari, courses details here
      • [ME1729] Physics & Biophysics (MEP5071018) - Prof. F. Marzari, courses details here
DOCTORAL SCHOOL in ASTRONOMY (Director Prof. G. Piotto)
When the program for Doctoral Research (PhD) started in Italy in 1982, the University of Padova organized a Doctoral School in Astronomy, which immediately obtained a national-wide attendance.
Aim of the PhD Program in Astronomy is the formation of young researchers of excellence at international level in their specific field of research in astronomy and astrophysics. The PhD in Astronomy contributed to the formation of a whole new generation of astronomers thanks also to the collaboration with the nearby Astronomical Observatory of Padova (OAPD) of the National Institute for Astrophysics (INAF).
The PhD Program has a three-year duration with a final exam for the defense of the PhD thesis. Because of the presence of foreign students, all the courses and the other activities are in English (including the mid-term evaluations and the final exam). The PhD thesis is written in English.


PhD thesis assignments
All thesis projects will be realized with a lively and friendly group of research. All of them are within international projects.
For additional information on us and our activities please look at the home page.
TitleEXOPLANETS SEARCH USING Kepler/K2, IN PREPARATION FOR CHEOPS, TESS AND PLATO
Topic
Exoplanets
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), M. Libralato, D. Nardiello
Abstract
This is a thesis to exploit K2/Kepler data, mainly for the search of exoplanets based on the transit method, in preparation for TESS and then PLATO.
Kepler has been an extremely-successful space mission, aimed at providing a statistical census of transiting planets around solar-type stars. After the nominal end of the mission, Kepler has recently entered the "K2" phase, where it will survey several stellar fields located on the ecliptic plane, for about two months each. The monitored regions will cover many stellar clusters and there will be the unprecedented opportunity to search for transits by low-mass, long-period planets among cluster stars. Our group has a well-documented expertise on high precision photometry in clusters that is priceless for exoplanetary studies because their age, chemistry and distance can be estimated way better than for field stars.
The work will allow the student to gain expertise on data reduction and analysis, starting from the techniques our group has developed to exploit crowded environments imaged by K2, in preparation for future planet-hunting and characterization of space missions, e.g. TESS and PLATO. TESS is a NASA mission (launch due by second half 2018), for a full sky survey for searching for exoplanets with the transit method.
The main task of the PhD student will be to prepare the software, and then use it to exploit TESS data. TESS exoplanet candidates may also be followed-up by CHEOPS. CHEOPS is and ESA mission, scheduled for a launch in the second half of 2018. The gained expertise will also be of fundamental importance for the preparation of PLATO, an ESA space mission for exoplanet search, expected to be launched in 2026.
The PhD student will become part of a large international collaboration, as members of our group have top level responsabilities in both in CHEOPS and PLATO missions.
TitleTHE FREQUENCY OF PLANETS IN OPEN CLUSTERS
Topic
Exoplanets
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), L. Malavolta
Abstract
Thousands of extrasolar planets have been discovered so far, but nearly all of them belong to isolated field stars, and their mass and radius are affected by large errors that transfer directly onto the precision of the planet parameters. On the contrary, distances, ages, mass and overall characteristics of stars in Open Clusters are much better measured than for field stars. Curiously, at the present time, only less than ten planets have been confirmed or validated around Main Sequence stars in OCs.
Our research group is leading a survey to discover and characterize planets in Open Clusters with HARPS and HARPS-N, the best instruments in the world for the search of exoplanets with the radial velocity (RV) method. While the survey is already delivering the first exciting results, a deep analysis of the dataset has not been carried out yet.
Within this framework, the PhD candidate will determine the detection limits of the survey as a function of the photospheric parameters and activity level of the stars, with the ultimate goal of determine the frequency of planets in Open Cluster. As part of this project, the PhD candidate will have the possibility of carrying out observations at the Italian 3.6m telescope Telescopio Nazionale Galileo (TNG) in La Palma (Canary Islands) and/or the 3.6m at ESO-La Silla (Cile) and he/she will take part in the selection and follow-up of interesting targets. The expertise gained through this project will give the PhD the ability to analyze and model RV observations, to detect low-mass planets in the presence of stellar activity through a variety of techniques, including Bayesian analysis and Gaussian Processes.
TitleATMOSPHERES OF EXTRASOLAR PLANETS
Topic
Exoplanets
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), V. Nascimbeni
Abstract
Within the young field of exoplanetary research, the present efforts are focused not only on the discovery of new planets, but also on a detailed characterization which include the study of their atmospheric properties, such as their composition, physical/chemical processes and dynamics.
Our group is actively involved in this field both on the observational side (with programs completed or ongoing at top-class observatories such as VLT, LBT, TNG) and on the development of theoretical models and interpretative tools. So far, the detection of exoplanetary atmospheres from the ground has been hampered by the Earth’s atmosphere, i.e., by the so called telluric contamination, which is especially limiting in the red part of the optical spectrum and in the infrared region. New techniques have been pionereed to overcome this limit, by combining high-resolution spectroscopy and cross-correlation algorithms in order to disentangle the stellar, planetary and telluric signals basing on their velocity signature. A thesis is offered with the aim of improving these techniques, implementing them in a software pipeline and testing them to optimally exploit proprietary and archival data from HARPS, HARPS-N and GIARPS. Such an approach would be particularly valuable to maximize the scientific yield of recently-installed instruments (CARMENES, PEPSI) and forthcoming spectrographs such as ESPRESSO and CRIRES, facilities that will be also used in the second part of the thesis.
TitleTHE PLATO INPUT CATALOG
Topic
Exoplanets
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), V. Nascimbeni
Abstract
Our group is deeply involved in PLATO-2.0, an ESA M3 space mission to be launched in 2026. PLATO will survey about half of the whole sky with exquisite photometric precision, aiming at discovering and characterizing thousands of transiting exoplanetary systems hosted by bright, nearby stars. Its main targets, dwarf and subgiant stars with a spectral type later than F5, must be selected in advance in order to optimize the observing strategy and the mission design. No existing catalog of stellar parameters is both deep and wide enough to this purpose, but Gaia already started delivering at least part of the needed information, and forthcoming GAIA data releases is expected to play a major role the preparation of the PIC. A thesis is offered to identify PLATO targets and obtain their most relevant parameters using Gaia catalog as a basis, and then complementing the information with other photometric and spectroscopic catalogs. During the thesis, the student will also develop the algorithms for stellar classification which will be used both for the PIC, but, also and more in general, for stellar astrophysics studies.
TitleEXOPLANETS SEARCH USING THE TTV/TDV METHOD
Topic
Exoplanets
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), V. Nascimbeni, L. Borsato
Abstract
A PhD thesis on TTV search of exoplanets is offered. The transit time variation (TTV) technique is a method to search for and characterize (including mass and orbital parameters) exoplanets in multiple exoplanet systems. Basically, it uses the variations of orbits - which cause changes in the transit times - due to the gravitational perturbations in a multiple-planet system.
We have an ongoing observational program for the detection of planets using the TTV technique (Holman+ 2005, Science 307, 1288), and we have developed and are presently extending a program to interpret the TTV signal. A huge number of nights at Asiago, Teide and La Palma, as well as CTIO and La Silla telescopes have been assigned. This data set, and additional, similar observations are the basis a PhD thesis project. The TTV analysis software has already been applied to Kepler/K2 data.
The PhD thesis will start from the developed expertise, and extend it to forthcoming (2018) CHEOPS and TESS data, also in preparation for PLATO. The student will be trained for observations at the telescope. The student will be inserted in an international collaboration, as our group is responsible for the TTV analysis of both CHEOPS and PLATO missions.
TitleWIDE FIELD OBSERVATIONS OF GLOBULAR CLUSTER
Topic
Stellar Populations
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), M. Libralato
Abstract
We propose a PhD thesis based on available OmegaCam@VST data, and other wide field facilities.
Over the last 20 years, the number of ground-based, wide-field imagers have considerably increased. Thanks to their large field of view and number of resolution elements, these detectors offer the unique opportunity to investigate globular clusters (GCs) in their entirety, from the center out to beyond the tidal radius. To investigate GCs in their outer parts is of fundamental interest in the multiple-stellar-population context. Different formation scenarios predict that the GCs should have been more massive in the past and hence they should have experienced a significant mass loss of primordial stars. Any trace of tidal tails in GCs can shed light on the multiple stellar populations, adding another piece on the still-broken puzzle of their origin.
We have at our disposal data sets that map different GCs (among which Omega Centauri, the most intringuing GC) which cover a region well beyond their tidal radius. The available data will allow to study the radial distribution of the different populations from the cluster core to the tidal radius and beyond.
The PhD student will learn how to reduce and analyze wide field images in general, and OmegaCam data in particular, and how to interpret the results. The work is in synergy with and complementary to our HST Globular Cluster Large Treasury Program.
Our group has a well-documented expertise on GCs and stellar populations in general. The possibility of formation stages at SpaceTelescope Science Institute, and other European and USA Universities, is offered.
TitleGLOBULAR CLUSTER IN NEAR INFRARED
Topic
Stellar Populations
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), M. Libralato, D. Nardiello
Abstract
Recent results based on the Hubble Space Telescope UV Treasury program GO-13297 (PI: Piotto) have demonstrated that almost all the Galactic globular clusters (GCs) host multiple stellar populations (MSPs), characterized by different chemical compositions (light-elements and Helium variations). Usually UV and optical observations exploit this MSP phenomenon at all the evolutionary stages in the GC colour-magnitude diagram.
However very faint and red M-dwarf stars (down to the hydrogen-burning limit) have not been investigated yet, because of observational limits in the ultraviolet/optical bands.
Recently, our group started to study the behavior of the MSPs in the lower MS of different GCs at near-infrared (NIR) wavelengths, using both space and ground-based data, and in preparation for the next generation of near-infrared instruments on JWST and E-ELT.
The PhD student will work on already available and forthcoming data, both from HST and various ESO telescopes, in preparation to exploit JWST NIR data. We are already working to prepare the first JWST project, after the call for proposals recently issued by NASA.
The main tasks of the thesis will be to: (1) adapt to JWST imagers the software developed for HST cameras (2) identify MSPs in the lower MS of some GCs, using archival and new data; (3) compute the relative age difference between the different stellar populations using the MS kink loci; (4) retrieve the MSP mass functions down to the hydrogen-burning limit. The possibility of formation stages at Space Telescope Science Institute (Baltimore, USA) is offered.
TitleMULTIPLE STELLAR POPULATIONS IN STAR CLUSTERS
Topic
Stellar Populations
Supervisor
Prof. G. Piotto (giampaolo.piotto at unipd.it), D. Nardiello
Abstract
The recent discovery (by our group) of multiple evolutionary sequences in Galactic globular clusters has seriously challenged the paradigm of star clusters hosting a simple stellar population, formed at the same epoch, from the same material. These new findings may have vast implications on star formation processes in the early Universe, and on population synthesis models used to interpret the light from galaxies at cosmological distances. This is a lively debated argument in the present astronomical literature.
Our research project is maily based on observations with the Hubble Space Telescope, and largest ground-based facilities. The PhD student will be inserted in a large international collaboration (of which the group in Padova is the leader) and work on the analysis of data from: (1) already approved and new proposed Hubble Space Telescope programs, and (2) approved ESO/VLTand LBT programs both with wide field imagers and high resolution spectrographs. The PhD student will gain an expertise on high precision photometry and astrometry on HST data and/or on the best techniques to exploit high-resolution spectroscopic data. The possibility of formation stages at the Space Telescope Science Institute, and other European and USA universities is offered.