Download Extrasolar Planet Studies:The Italian Contribution

Extrasolar Planet
Observational Studies: The
Italian Contribution
Raffaele Gratton
INAF – Osservatorio Astronomico
di Padova
Congresso SAIt, Teramo, 8-52008
Exoplanets science
Extrasolar planets one of the
major astronomical topic of the
last decade
Increasing interest in the
coming years, when moving to
planets with lower masses,
down to Earth-mass planets
Many surprises: planets and
planetary systems very different
from the Solar System
Congresso SAIt, Teramo, 8-52008
V391Peg
Red Giants
SPHERE
EPICSOpen Clusters
RATS PLATO
ΩTrans
SARG
GAIA
M. Perryman, 2001
(from: http://www.obspm.fr/encycl/searches.html)
Congresso SAIt, Teramo, 8-52008
SARG: Planets
in binaries
Collaboration of people in:
-INAF-OAPD
-INAF-OACT
-CGG
-Un. Texas at Austin
Long Term Project using SARG at TNG
Main Goals:
- May planets form in close binaries?
- Understand planet-metallicity
connection
Sample: ~100 nearly equal mass visual
binaries (projected separation 100-1000
AU)
Monitored over 8 years (~120 observing
nights)
Typical precision RV: 5 m/s
Recent Publications:
Desidera et al. (2007) astro-ph 0705.3141
Desidera & Barbieri (2007) A&A 462,345
Martinez Fiorenzano et al. (2005) A&A 442,775
Congresso SAIt, Teramo, 8-52008
SARG: Planets
in binaries
May planets form in close
binaries?
There are less planets in close
binaries
Congresso SAIt, Teramo, 8-52008
SARG: Planets
in binaries
The planet-metallicity connection:
-Either planets form more easily in environments
more rich in metals (more grains)
-Or alteration of primordial abundances due to
infall of metal-rich material
Stringent upper limits from binaries composed of
very similar late-F early-G stars (where the
convective envelope is tiny)
Congresso SAIt, Teramo, 8-52008
Extreme RV performances
with SARG
SARG use for asteroseismology campaigns reveals extreme RV
performances: nigthly averages over a week have dispersions of
about 20 cm/s, sensitivity to 2 MEarth planets in short periods
Congresso SAIt, Teramo, 8-52008
SARG: Determine the
frequency of Hot Neptunes
Intensive program: ~60 nights/yr for two years at TNG
26 nights allocated at TNG for AOT17
Congresso SAIt, Teramo, 8-52008
First results: requested
accuracy (1-2 m/s)
achieved
Candidates from lower accuracy program at
McDonald Observatory
Congresso SAIt, Teramo, 8-52008
Planets around Red Giants -1
• Group leadered by Luca
Pasquini (ESO)
• Italian contribution: Leo Girardi
(INAF-OAPD) & Katia Biazzo
(OACT)
• Importance: Search for planets
around quite massive stars
• Data gathered at ESO & TLS
telescopes
• Results: >10 planets
discovered
Congresso SAIt, Teramo, 8-52008
Planets around Red Giants - 2
• Massive planets
around massive stars
are common (>10%
of the stars)
M<1.1 Mo
Congresso SAIt, Teramo, 8-52008
M>1.1 Mo
Planets around
Red Giants - 3
• No correlation
between presence of
planets and
metallicity, at variance
with results G-K main
sequence stars
Congresso SAIt, Teramo, 8-52008
Time Delays: the case of V391
Pegasi (pulsating B subdwarf)
• Group leader: Silvotti (OA
Capodimonte)
• Importance: Search for
planets around evolved
stars
• Main Result: Quite
unexpected discovery of
a planet which survived
stellar evolution on the
RGB
• References:
- Silvotti et al., 2007, Nature, 449,
189
Congresso SAIt, Teramo, 8-52008
Transits: Open clusters
• PI Piotto (Univ. PD)
• Un. PD+INAF-OAPD
• Do planets form also in dense
environments?
• Small statistics  Metal-rich
open clusters
• NGC6791:
– 10 nights at CFHT+San Pedro
Martir+Loiano
• NGC6253:
– 10 nights at WFI@La Silla+AAT
Congresso SAIt, Teramo, 8-52008
Transits: Open clusters
Highly accurate
photometric curves
(error of a few
thousandths of mag
for the upper MS)
Congresso SAIt, Teramo, 8-52008
Transits: Open clusters
NGC6791:
– Null result
– detailed simulations foresee the
presence of 2-3 transiting planets.
– The probability that the null detection is
simply due to chance coincidence is
estimated to be 3%-10%, depending on
the metallicity assumed for the cluster
– New observations scheduled in July
NGC6253: 1 candidate
Congresso SAIt, Teramo, 8-52008
Transits: TReS and HATP survey
•
Italian participant: A. Sozzetti (OATO)
Publications:
• Observational Tests of Planet Formation Models (ArXiv0711:0409)
• HAT-P-4b: A metal-rich low-density transiting hot Jupiter (ArXiv0710:0602)
• TrES-4: A Transiting Hot Jupiter of Very Low Density (ArXiv0708:0834)
• HAT-P-3b: A heavy-element rich planet transiting a K dwarf star (ArXiv0707:4267)
• TrES-3: A Nearby, Massive, Transiting Hot Jupiter in a 31-Hour Orbit
(ArXiv0705:2004)
• HD147506b: A Super-Massive Planet in an Eccentric Orbit Transiting a Bright Star
(ArXiv0705:0126)
• Improving Stellar and Planetary Parameters of Transiting Planet Systems: The Case
of TrES-2 (ArXiv0704:2938)
• The Transit Light Curve Project. VI. Three Transits of the Exoplanet TrES-2
(ArXiv0704:2907)
• TrES-2: The First Transiting Planet in the Kepler Field (astro-ph/0609:9335)
• A Keck/HIRES Doppler Search for Planets Orbiting Metal-Poor Dwarfs. I. Testing
Giant Planet Formation and Migration Scenarios (astro-ph/0605067)
Congresso SAIt, Teramo, 8-52008
Spectroscopic determination of the
atmospheric parameters and chemical
abundance of the parent star
Detailed LTE analysis of a set of Fe I and Fe
II lines yields Teff=5850±50 K, log
g=4.4±0.1, and [Fe/H]=−0.15±0.10.
New method to derive mass and radius of
the star:
M⋆ = 0.980±0.062 Mo
R⋆=1.000±0.034 Ro
Age = 5.1±2.5 Gyr
Mp=1.198±0.053 MJ
Rp=1.220±0.044 RJ,
 TrES-2 is the most massive among the
currently known nearby transiting hot
Jupiters
Congresso SAIt, Teramo, 8-52008
Transits:
HD17156b
Barbieri et al. (2007, A&A, in
press):
The longest period (21.2 d) and
most eccentric (e=0.67)
transiting planet
Rossiter effect from SARG radial
velocities: orbit of planet is
coplanar with stellar rotation
Decisive contribution by Italian
amateur Astronomers for the
photometric part
Congresso SAIt, Teramo, 8-52008
Transits: RATS (RAdial velocities
and Transit Search)
• Collaboration: INAF (PD, CT, NA, PA), Un. Padova (Astronomy and
Physics Dept.), and ESA
• Goal: search of giant planet transits and spectroscopic
characterization
• Intruments:
– Schmidt 67/92 cm: FoV~1 square degree
– Copernico Telescope
• Open to collaborations with amateurs
Congresso SAIt, Teramo, 8-52008
Transit survey approved for GTO bright time on VST
PI: Snellen (Leiden Observatory)
Italian Participation: INAF-OA Capodimonte
INAF-OAPD
OmegaTranS will make use of the Omegacam CCD
camera on the newly built VLT 2.6m survey
Telescope (operational early 2009)
The CCD camera
OmegaCAM is a 1 square degree wide field, optical,
16k X 16k camera for the VLT Survey Telescope
(VST). It consists of 32 low-noise array, resulting in
0.26 arcsecond pixels. It has been build by a
consortium of Dutch, Italian, and German institutes.
Congresso SAIt, Teramo, 8-52008
• Observing strategy
At first instance, 3 weeks of bright GTO time (plus additional time
that will be persued through GO rounds) will be used to monitor 4
densely populated star fields towards the galactic disk at low
declination. Cycle time will be approximately 8.5 minutes, with 20
sec. exposures - targeting about ~200,000 F,G, and K dwarf stars at
R=13.5-17.5 for at least 1000 epochs during the first observing
season.
Data Processing
The data reduction will be performed in the (hardware and software)
framework of AstroWise, using difference imaging. The expected
data flow is 3.5 Tbyte per year (1.5 Tb per partner), well within the
capacity of AstroWise.
Congresso SAIt, Teramo, 8-52008
Transits: PLATO
A proposed satellite for ESA Cosmic Vision, Approved for Phase A
PI: Català (LESIA)
Italian participation:
Congresso SAIt, Teramo, 8-52008
Congresso SAIt, Teramo, 8-52008
PLATO
PLATO limit
Congresso SAIt, Teramo, 8-52008
Comparison between PLATO,
CoRoT and Kepler
Congresso SAIt, Teramo, 8-52008
Astrometric detection: GAIA
Congresso SAIt, Teramo, 8-52008
Exoplanets Direct Imaging from
Ground: SPHERE for VLT
Congresso SAIt, Teramo, 8-52008
The niche of direct detection
• Definition of outer parts of the systems (from the
snowline outward, 3-40 AU) crucial to understand
formation mechanisms of planetary systems
• Indirect methods are not efficient at large separations:
–
–
–
–
Radial velocity signal very small
Transits too rare and inefficient
Astrometry very slow
Microlensing very rare
• Direct detection is efficient:
– For young giant planets if contrast is ~106-107
– For rocky planets in the habitable zone and old giant planets
near the snow line if contrast is ~109
• Direct detection allows planet characterization
Congresso SAIt, Teramo, 8-52008
Current limits at large separations

Nielsen et al. 2007
Congresso SAIt, Teramo, 8-52008
SPHERE
Planet Finder for VLT, with the goal of direct detection of
extrasolar planets
Very challenging goal: need high contrast at small
separation from bright stars
A brief history:
2 feasibility studies in 2002-2003: VLT-PF (LAOG) and
CHEOPS (MPIA, including OAPD)
2004 merging of the projects
Fall 2007: PDR
Schedule:
FDR end 2008
Commissioning: fall 2010
Congresso SAIt, Teramo, 8-52008
SPHERE Concept
Reduce WFE
and diffraction
pattern
Allow differential
Imaging
Congresso SAIt, Teramo, 8-52008
Consortium
P.I. J.L. Beuzit (LAOG)
CNRS/LAOG (Grenoble, F) INAF/Padova Observatory (I)
CNRS/LAM (Marseille, F)
CNRS/LESIA (Paris, F)
CNRS/LUAN (Nice, F)
ONERA (Paris, F)
MPIA
IFS (Heidelberg, D)
 Instrument control software
Observatoire de Genève (CH)
(resp. A. Baruffolo)
 Science (Survey)
ETH (Zürich, CH)
 ~17% of FTE
NOVA (Amsterdam, NL)

ASTRON (Amsterdam, NL)
260 GTO nights
Congresso SAIt, Teramo, 8-52008
Performances
Contrast of 16 mag
at 0.5 arcsec from
a J=5 star
Improvement of 2
orders of magnitude
with respect to
current
instrumentation
AO mag limit R=9
Congresso SAIt, Teramo, 8-52008
Science Objectives
• Directly detect photons from extrasolar giant planets
• Explore the mass-period distribution (1-20 Mjup, 1-1000
years)
• Survey an extended number of stars
• First order characterization of the atmosphere (clouds, dust
content, methane, water absorption, effective temperature, radius, dust
polarization)
 Understand the planetary system origins
Congresso SAIt, Teramo, 8-52008
Science Objectives
Direct-imaging of planets:
large masses, towards long
periods, young/nearby
systems
RV-transit planets: old/quiet
stars, short periods, towards
low masses
Complementarity in
MASS
AGE
PERIOD
Congresso SAIt, Teramo, 8-52008
Number of detected planets

Few tens planet detections expected
Congresso SAIt, Teramo, 8-52008
EPICS
• EPICS is an instrument project for the direct imaging and
characterization of extra-solar planets with the
European ELT
• The eXtreme Adaptive Optics (XAO) system
• The Diffraction Suppression System (or coronagraph)
• The Speckle Suppression System
• The Scientific Instrument(s)
– Integral Field Spectroscopy
– Differential Polarimetry
– A speckle coherence-based instrument
• Data processing strategy
Congresso SAIt, Teramo, 8-52008
EPICS PHASE A
Conceptual Design
• 24 months (Kick Off meeting Oct. ’07)
• Consortium:
– ESO, LAOG, LESIA, LUAN, LAM, ONERA, Oxford, INAFPadova, ETH, UvA, ASTRON, UU
Congresso SAIt, Teramo, 8-52008
EPICS PHASE A
Work Breakdown Structure
Italian involvement:
FTE: 1.35 staff + 2.0 FTE project
Money: 81 kEuro (32 kEuro ESO + 49 kEuro FP7)
Congresso SAIt, Teramo, 8-52008
EPICS Science Objectives
Terrestrial Planets in HZ
• Some chance for the ~70 M dwarfs (-53<Dec<7) closer
than 10pc (HZ at 10 pc is at 15mas, probably beyond inner
working angle)
– However, tidal locking, atmosphere evaporation, likely
thin (Lissauer) or no (Brain) atmosphere
• Some chance for rocky planets inwards of HZ (Venus) for
the ~100 G, K and M stars within 10pc
• Improbable to detect even for the handful of closest K-and
and G-stars
• Little hope for spectroscopy at R>20
Congresso SAIt, Teramo, 8-52008
Detection of rocky planets
5 pc
10 pc
20 pc
50 pc
Congresso SAIt, Teramo, 8-52008
EPICS Science Objectives
Giant Planets, unique science
• Young self-luminous gaseous planets in star forming regions or
young associations
– EPICS can achieve good resolution even for star forming regions
at ~100pc, young planets at >3 AU can be detected, very
important observation to understand planet formation
• Mature giant planets at orbital distances between ~5 and 15 AU in the
solar neighbourhood ( 20 pc)
– Not an easy observation
– Determine frequency and mass distribution of giant planets
• Warm Jupiters that have been discovered by radial velocity searches
– Fairly easy, spectral characterization
– Understand giant planets’ atmosphere composition and structure
Congresso SAIt, Teramo, 8-52008
EPICS
Science
Giant planets
fromObjectives
RV surveys
Congresso SAIt, Teramo, 8-52008