ESPRESSO:the search for rocky planets

in the habitable zone with VLT

Rafael Rebolo (IAC-CSIC)on behalf of the ESPRESSO Consortium

ESO day, Granada 10 February 2011

Science MotivationScience Motivation

1. Measure high precision radial velocities to search for rocky planets

2. Measure the variation of physical constants

3. Analyze the chemical composition of stars in nearby galaxies.

ESPRESSO (the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observation) is a high-efficiency, high resolution, fiber-fed spectrograph of high mechanical and thermal stability located at VLT incoherent Coudé Focus. It can be operated with one or up to 4 UTs to be the first instrument able of using a 16-m equivalent telescope.

SuperSuper--Earths from RV surveysEarths from RV surveys

Santos et al. (2004), Pepe et al. (2007)

HARPS1.089.5510.5HD 160691 d

Lovis et al. (2006)HARPS0.868.6710.5HD 69830 b

Howard et al. (2009)HIRES0.835.409.2HD 7924 b

Mayor et al. (2009)HARPS0.7720.59.2HD 40307 d

Forveille et al. (2008)HARPS0.498.788.4HD 285968 b

Leger et al. (2009), Queloz et al. (2009)

CoRoT/HARPS

0.933.708.4CoRoT-7c

Udry et al. (2007)HARPS0.3183.67.7Gl 581 d

Rivera et al. (2009)HIRES1.085.777.6HD 1461 b

Bouchy et al. (2009)HARPS0.789.377.6HD 181433 b

Mayor et al. (2009)HARPS0.779.626.9HD 40307 c

Bonfils et al. (2010)HARPS76.0Gl 433 b

Rivera et al. (2005)HIRES0.321.945.7Gl 876 d

Bonfils et al. (2010)HARPS76.0Gl 667C b

Charbonneau et al. (2009)

MEarth/HARPS

0.161.585.7GJ 1214 b

Lo Curto et al. (2009)HARPS0.873.935.4HD 215497 b

Udry et al. (2007)HARPS0.3112.95.0Gl 581 c

Vogt et al. (2009)HIRES0.954.225.161 Vir b

Leger et al. (2009), Queloz et al. (2009)

CoRoT/HARPS

0.930.854.8CoRoT-7b

Mayor et al. (2009)HARPS0.774.314.2HD 40307 b

Mayor et al. (2009)HARPS0.313.151.9Gl 581 e

ReferenceInstrumentm1 [M�]P [days]m2 sini [MÅ]Name

RV detected exoplanetswith masses below10 times the Earth mass

Between 25% and 50% of solarBetween 25% and 50% of solar--like stars do like stars do possess closepossess close--in ice giants and superin ice giants and super--Earths. Earths.

This is in agreement with Monte Carlo simulations This is in agreement with Monte Carlo simulations of planet formation (of planet formation (MordasiniMordasini et al. 2009)et al. 2009)

Main trigger for the building of ESPRESSO, which will be able,with its instrumental precision of 10 cm/s, to extensively explore thelow-mass tail of the exoplanet distribution and to find rocky planets within the habitable zone (HZ) around other stars.

What does ESPRESSO have we What does ESPRESSO have we do not have?do not have?

ESPRESSO will combine the following unique characteristics:

• A super-HARPS on a 10 m-class telescope

• An instrumental efficiency comparable to or better than existing facilities

• A wavelength calibration far more accurate than what any existing facility can offer

• The highest-resolution instrument on a 10 m-class telescope (R=140,000 in standard mode)

• A ultra-high resolution mode (R~225,000), far beyond what other existing facilities can offer

• A spectrograph on a 16m telescope, the largest photon-collecting area until ELTscome online

• Complete spectral coverage from 380 to 800 nm in one shot at record-high resolution

• An instrument producing the cleanest, best-quality spectra, both at high and low SNR

DetectabilityDetectability ofof rockyrocky planetsplanets withwithESPRESSO ESPRESSO

• the detection of Earth-like planets, down to 1-2 times the Earth mass, on orbitsextending up to the habitable zone (HZ) around their parent stars

• the precise determination of the mass distribution down to a few Earth masses forclose-in planets, including a characterization of the "intermediate-mass desert" andpossible hints to distinguish between "failed cores" and truly telluric planets;

• the determination of the semi-major axis distribution of low-mass planets, yieldingimportant information on migration phenomena;

• the global frequency of low-mass planets around solar-type stars, and how itcompares to the frequency of gas giants;

• the distribution of orbital eccentricities for low-mass planets, which may reveal the role of dynamical interactions in the shaping of planetary systems;

• the study of chemical abundances in stars hosting low-mass planets, and how itcompares to the well-known metalrich character of stars hosting gas giants;

• the dependence of the properties of low-mass planets on stellar mass;

Exoplanet research goals with ESPRESSO:

A Pandora-box of other science

Given its efficiency, the high spectral resolution - and in particular the R = 225’000 mode, the extreme high radial velocity precision, and the possibility of combining up to 4 UTs, we expect that ESPRESSO will open a new parameter space in observational astronomy with hopefully many new and unexpected results.

A preliminary, incomplete list of additional exciting sciences cases, which can be addressed with ESPRESSO by the astronomical community:

Chemical composition of stars in local galaxiesInvestigation of metal-poor starsStellar oscillations, asteroseismologyDiffuse stellar bands in the interstellar mediumChemical enrichment of IGMGalactic winds and tomography of the IGMChemical properties of protogalaxiesCosmology and expansion of the UniverseFurther extra-solar planet science

o The Rossiter-McLaughlin effecto Transmission spectroscopyo Planets in nearby open clusters and galaxies

Variability of fundamental constants?

• A goal for ESPRESSO is to search for variability of the fundamental fine structure constant = e2/ђc and the electron-to proton mass ratio at the level of 1 ppm.

• This corresponds to being able to measure the position of absorption lines in high redshift quasar absorption systems with an accuracy of about 10 m s-1. The new observations will either confirm the claimed variability or will place more stringent bounds at lower level.

• The fine structure constant is related to the strength of the electromagnetic force and the proton-to-electron mass ratio is related to the ratio between the strong and weak nuclear forces. If the fundamental constants variation can be traced back in space-time and the variation is – as suggested by some models – closely linked to the evolution of a scalar field responsible for the presence of dark energy, then we will be able to trace the evolution of this scalar field (Caroll 1998, Avelino et al 2006).

•A confirmation of variability with high statistical significance will open a window to new physics beyond the Standard Model and possibly shading new light on the nature of Dark Energy (see e.g. Avelino et al. 2006 Phys. Rev.).

•

Variability of fundamental constants?

• Observations of spectral lines in distant QSOs gave the first hints that the fine-structure constant might change its value over time, being lower in the past by about 6 parts per million (Webb et al 1999, Murphy et al. 2004). More recently, also µ= mp / me has been found to vary by Ivanchik et al (2005), Reinhold et al (2006). However, recent results suggest no variation. The debate is still open and demands a high-resolution spectrograph for a definitive clarification.

•Present hint for α variability is of Δ/ = (-5.7 ± 1.1) ppmfrom averaging 143 systems,Δ µ/µ = (20 ± 6) ppmfor two systems.

With ESPRESSO we expect to measure both constants at the level of 1 ppm or better in individual systems

ESPRESSO ConsortiumESPRESSO ConsortiumPI F. PI F. PepePepe ((GeneveGeneve Observatory, Switzerland)Observatory, Switzerland)CoCo--PI R. PI R. ReboloRebolo ((InstitutoInstituto de de AstrofAstrofíísicasica de Canarias, Spain)de Canarias, Spain)CoCo--PI N. Santos (CAUP, Portugal)PI N. Santos (CAUP, Portugal)CoCo--PI S. PI S. CristianiCristiani (Obs. Trieste, INAF, Italy) (Obs. Trieste, INAF, Italy) ESO representative H. Dekker ESO representative H. Dekker Project Manager (D. Project Manager (D. MegevandMegevand, , GeneveGeneve Obs.)Obs.)System Engineer (F. System Engineer (F. ZerbiZerbi, Obs. Milan, Obs. Milan--INAF)INAF)PA/QA (M. PA/QA (M. AmateAmate, IAC), IAC)Project Scientist (P. Project Scientist (P. MolaroMolaro Obs. Trieste)Obs. Trieste)

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Science Team and Engineering TeamsScience Team and Engineering Teams

ESPRESSO conceptESPRESSO concept

Pepe et al. 2010 SPIESpanó et al. 2010 SPIE

ESPRESSO Combines ESPRESSO Combines lightlight fromfromseveralseveral VLT VLT UTsUTs

ESPRESSO Combines ESPRESSO Combines lightlight fromfromseveralseveral VLT VLT UTsUTs

Summary of the characteristics of Summary of the characteristics of ESPRESSO in its main modesESPRESSO in its main modes

ESPRESSO spectral format ESPRESSO spectral format redred armarm

In the 1-UT mode: SNR of 10 is obtained with 3 exposures of 20 minutes on a V = 17.1starIn the 4-UT mode, SNR of 10 on a V = 20.1 star is achieved with a single 1-hourexposure.

For reference, the 10 cm s-1 limit is shown.

SPIE 2010

Laser-combversus Th-Ar

Recent results with HARPS-laser combshow stability at level of 4 cm/sin short timescale

Lo Curto et al. 2011,ESPRESSO Technical Kick-off meeting

andAbstract submitted to next European Conference on Lasers

Tasks Committed by the IAC as agreed with theESPRESSO Consortium:

Detailed design of the fiber link subsystem October 2011- December 2012

Detailed design of the spectrometer optics (VPHs, Collimators). October 2011- Dec 2012

Detailed design of the spectrometer opto-mechanics system (includes the optical bench, optical mounts and support equipment). October 2011- December 2012

Procurement of the Optical Components of the spectrometer (except the echellegrating and the two cameras). January 2013-October 2014

Development of the optical bench and support equipment January 2012- December 2013.

Validation of the optical and opto-mechanical components. June 2014-December 2014

Product/Quality Assurance for the whole instrument October 2010- December 2014

Development of Data Reduction and Data Analysis Software packages January 2012- December 2014

Science programme preparation. January 2012- December 2014

Engineer team :M. Amate (local project manager, and PA/QA) IAC F. Tenegi (opto-mechanical engineer, IAC)S. Santana (opto-mechanical engineer, IAC)J.L Rasilla (optical engineer, IAC)A. Fragoso (optical engineer, IAC)

Science team:M.R. Zapatero Osorio (deputy project scientist, CAB)J. González Hernández, C. Allende, R.J. García López, G. Israelian, M. Esposito

RRL (co-PI, IAC)

ESPRESSO Team in Spain

ESPRESSO as a CODEX precursor

• ESPRESSO has not to be seen as a CODEX@E-ELT prototype in the sense that it willnot be possible to simply clone it for the E-ELT.

• Nevertheless, ESPRESSO can be considered as a precursorof CODEX at the E-ELT for aspects concerning technology development, operationsand scientific use. Precious information and experiences have been and will be exchanged between the two projects.

ESPRESSO timescales• Phase A review was passed in March 2010.

• Science and Technology Com. Recommended in May 2010.

• Council endorsed the recommendation for construction in June 2010.

• Technical Kick-off took place in January 2011

• Preliminary design review planned for October 2011

• Manufacturing, Assembly, Integration and Verification 2012-2014

• Commissioning and acceptance at Paranal in 2015

• … beyond 2015, science exploitation by the community!

Thanks !