Basic Training New Worlds BST_15 - FND - SPA - NEW Dr. Kleomenis Tsiganis Aristotle University of Thessaloniki [email protected] Lesson Title COL - COM - USR - USK 1 15 - May - 2014 Course Flow Basic Training Fundamentals Space Sciences Structure and Techniques for Cosmic origins evolution of Galaxy zoo The life of stars observational the Universe astrophysics Birth of planetary Comparative New worlds The Solar system systems planetology Earth - Sun Observing the The Sun Planetarium visit interactions night sky Lesson Title COL - COM - USR - USK 2 15 - May - 2014 New Worlds c. 400 - 300 B.C.: Democritus and Epicurus suggest infinite worlds similar or different to our own with living creatures c. 1600 CE: Giordano Bruno claims that the Sun is just another star like the rest and every star could harbor planets with intelligent life... 1992: the first system of planets orbiting a pulsar is detected by Wolszczan & Freil PSR1257+12 , artist impression Credit: NASA/JPL_Caltech Lesson Title COL - COM - USR - USK 3 15 - May - 2014 Lesson Objectives 1 Describe observational/detection techniques 2 Describe physical and orbital properties of planets 3 What's next ? Lesson Title COL - COM - USR - USK 4 15 - May - 2014 Lesson Outline Observational / detection techniques 1 – Radial velocity and Transits – Imaging and other techniques Physical and orbital properties 2 – Statistics – Earth - like planets What's next ? 3 – Missions: past and future – Habitability issues Lesson Title COL - COM - USR - USK 5 15 - May - 2014 New Worlds 1995: First exoplanet around a Sun - like star (51 Peg) found by Mayour & Quelloz Mass of planet ~ 0.5 M Jup Orbital period ~ 4.2 days ! 51 Peg and Bellerophon, artist impression (Credit: ESO ) Lesson Title COL - COM - USR - USK 6 15 - May - 2014 New Worlds 2005 - 08: First exoplanet directly imaged around Fomalhaut (25 ly) by Kalas et al. Dagon orbits the star at ~115 AU! Sketch of Fomalhuat system (Credit: NASA/ESA/STScI ) Lesson Title COL - COM - USR - USK 7 15 - May - 2014 New Worlds Total confirmed exoplanets (03/2016) = 2086 (ESP Encyclopedia) Unconfirmed “Kepler” candidates ~ 3800 ! ~ 500 multiple planet systems They're everywhere (~1.6 planet/star in Galaxy) Credit: NASA/JPL Scientific American Lesson Title COL - COM - USR - USK 8 15 - May - 2014 New Worlds 51Peg b discovered by Radial Velocity technique ( ELODIE specr.) Measures Doppler shift of light from star, as it moves around barycenter Gives orbital period and lower bound of planet's mass * Sketch of RV method (Credit: ESO ) Rvmeasurement - 51 Peg Lesson Title COL - COM - USR - USK 9 15 - May - 2014 A planet on circular orbit has Eq. of the center of mass (momentum conservation) gives: Wobble / Doppler effect measures: with a period: And this gives a lower limit for M P through: (for known M * ) Lesson Title COL - COM - USR - USK 10 15 - May - 2014 New Worlds HD209458b first planet discovered by Transits technique (first transit of Venus observed by J. Horrocks in 1639) Credit: NASA Gives orbital period and radius * Lesson Title COL - COM - USR - USK 11 15 - May - 2014 Observable only if 0<b<1 : Gives radius (and orbital period) Variations in Transit Times (TTVs) reveal perturbations by other planets(?) Combination of RV (Doppler) and Transits mass, radius and density Lesson Title COL - COM - USR - USK 12 15 - May - 2014 New Worlds Other techniques: Transit Timing Variations (multiple planets), astrometry ( Gaia ), micro - lensing, pulsar timing, ... New imaging techniques (vortex coronograph ) allow direct imaging – first resolved HR8799, Hale Telescope (Mt. Palomar) Update on HR8799, B. Zucjerman, Keck Obs. NASA/JPL/Caltech/Palomar Lesson Title COL - COM - USR - USK 13 15 - May - 2014 New Worlds Coronograph to be used in many large instruments (Gemini, VLT, JWT) also with adaptive optics (Subaru, SCExAO) Expected to have many more directly imaged planets soon... Images of: AB Pictoris and β - Pictoris by NACO/VLT instrument (ESO) Lesson Title COL - COM - USR - USK 14 15 - May - 2014 New Worlds Atmospheres studied for transiting planets (day/night temperature variation, spectral features,...) HD 189733 studied using Spitzer , HST , VLT : H 2 O, CH 4 , O 2 , CO Na found in HD209458b. Clouds detected in Kepler - 7b. Water found in more planets... Artist's impression of HD189733 b and its evaporating atmosphere (NASA/Goddard SFC) Lesson Title COL - COM - USR - USK 15 15 - May - 2014 Lesson Outline Observational / detection techniques 1 – Radial velocity and Transits – Imaging and other techniques Physical and orbital properties 2 – Statistics – Earth - like planets What's next ? 3 – Missions: past and future – Habitability issues Lesson Title COL - COM - USR - USK 16 15 - May - 2014 New Worlds Mass – orbital radius diagram As instrument improve, so do our statistics “Hot” Jupiters Not so hot... Super - Earths excess at small periods (formation?) Earth - like planets found (Credit: Wikipedia Commons / data from Open Extrasolar Planets Catalogue) Lesson Title COL - COM - USR - USK 17 15 - May - 2014 New Worlds Orbital eccentricities: all over (formation ?) Not, for periods <20 days [tidal circularization ] (Credit: P. Armitage/ UC) Lesson Title COL - COM - USR - USK 18 15 - May - 2014 New Worlds Earth's twin announced on July 2015: Kepler - 452b ~5 times larger in mass, but rocky and orbits a Sun - like star at ~1 AU Comparison of Earth to K - 452c ; ~1.6 Earth radii (Credit:NASA/Ames/JPL - Caltech) Lesson Title COL - COM - USR - USK 19 15 - May - 2014 New Worlds New Kepler Candidates: Period vs Radius (Credit: NASA/Ames) Lesson Title COL - COM - USR - USK 20 15 - May - 2014 New Worlds Super - Earths : up to 1.5 Earth radii density increases → rocky! 1.5 - 4 Earth radii density decreases → gases! One mega - Earth (K - 10c) found and one possible super - Neptune (K - 101b / analyzed by HARPS) Some “species” seem alien to us, because they form around very different types of stars... Comparison between Earth, Kepler - 10c and Neptune(Credit: Open Exoplanet Catalogue) Lesson Title COL - COM - USR - USK 21 15 - May - 2014 New Worlds Earth - analogues (in the habitable zone) of different types of stars (Credit: NASA/Ames/JPL - Caltech) Lesson Title COL - COM - USR - USK 22 15 - May - 2014 New Worlds Multi - planet systems exist, but generally differ from ours... (Credit: NASA/JPL - Caltech) Are we the weired system ? Lesson Title COL - COM - USR - USK 23 15 - May - 2014 Lesson Outline Observational / detection techniques 1 – Radial velocity and Transits – Imaging and other techniques Physical and orbital properties 2 – Statistics – Earth - like planets What's next ? 3 – Missions: past and future – Habitability issues Lesson Title COL - COM - USR - USK 24 15 - May - 2014 New Worlds CoRoT Mission (CNES/ESA, 2006 - 2013) – 27cm telescope to study stellar oscillations and transits 32 planets found/confirmed from ground CoRoT - 7b was the first (2009) found to be comparable to Earth Precursor to Kepler and ... PLATO (ESA) to be launched 2024 Multiple cameras to study >1 million stars ... Expected to find a multitude of Earth - like planets in the habitable zones of different stars (Credit: CNES) Lesson Title COL - COM - USR - USK 25 15 - May - 2014 New Worlds Kepler Mission (NASA, 2009 - 2014) – 95cm telescope to sudy transiting planets in a fixed field of view of ~150,000 stars More than 1,000 confirmed and 4,000 candidate planets ! Found planets as small as Earth (e.g. Kepler - 186f) and Earth's “twin” in the habitable (Credit: NASA/JPL) Lesson Title COL - COM - USR - USK 26 15 - May - 2014 New Worlds Plato is expected to be a cornerstone space mission other similar missions CHEOPS (Swiss+ESA) and TESS (NASA) James Webb Space Telescope (NASA/ESA/CSA) to succeed HST/Spitzer Ground: E - ELT, ALMA Important elements in Europe's Roadmap of Research on Astrobiology From “AstRoMap” final report, 2016 Lesson Title COL - COM - USR - USK 27 15 - May - 2014 New Worlds Habitability of new worlds is a tantalizing question Habitable Zone: annular region around star where water can be liquid on planets' surface (plus...) Lesson Title COL - COM - USR - USK 28 15 - May - 2014 New Worlds Other conditions / constraints shuld be imposed, e.g orbit, internal structure, magnetic field... * more on Comparative Planetology ... Lesson Title COL - COM - USR - USK 29 15 - May - 2014 Lesson Outline Observational / detection techniques 1 – Radial velocity and Transits – Imaging and other techniques Physical and orbital properties 2 – Statistics – Earth - like planets What's next ? 3 – Missions: past and future – Habitability issues Lesson Title COL - COM - USR - USK 30 15 - May - 2014 Lesson Summary 1 Observational/detection techniques ~6,000 planets detected/suspected so far. RV and Transits (+TTVs) most efficient techniques so far → period, mass and radius. Transits and Imaging allow to study atmosphere 2 Physical and orbital properties of planets Jupiters (and larger) – hot or not – and super - Earths (~Neptunes) predominant. All possible eccentricities (formation?). Earth analogues but also 'strange' species and multiple systems found 3 What's next ? New dedicated missions (PLATO) and ground(ALMA/E - ELT) - and space - based (JWST) observatories expected to greatly enhance our capabilities. Need more work (and synergies) to understand habitability Lesson Title COL - COM - USR - USK 31 15 - May - 2014 References Lissauer, J.J. and de Pater, I.“Fundamental Planetary Science”, Cambridge University Press, 2013. http://www.exoplanets.org/ Armitage, P. “Astrophysics of Planet Formation”, Cambridge University Press, 2010. www.exoplanet.eu http://planetquest.jpl.nasa.gov/ Lesson Title COL - COM - USR - USK 32 15 - May - 2014.