Eva Meyer MPIA-Student-Workshop, Italy Various information from different detection methods

Eva Meyer MPIA-Student-Workshop, Italy Outline Introduction Indirect detection techniques –Radial Velocity –Astrometry –Transit –Microlensing Direct detection techniques –Reflected starlight –Imaging André

Eva Meyer MPIA-Student-Workshop, Italy Introduction so far 215 planets are detected ( ) 21 multiple systems first announcements: Peter van de Kamp ( ) Astrometric study of Barnard‘s star from plates taken with the 24-inch Sproul refractor (AJ, vol. 68, 515) BUT: 1952 by Otto Struve: Proposal for a project of high-precision stellar radial velocity work (The Observatory, No. 870) first detections: 1995 by Mayor & Queloz: 0.5 M Jupiter P = 4.2 days around 51 Peg

Eva Meyer MPIA-Student-Workshop, Italy Orbital parameters Period P Semi-mayor axis a Eccentricity e Inclination i Argument of perihelion ω Longitude of the acsending node Ω True anomaly T Time of periapsis τ

Eva Meyer MPIA-Student-Workshop, Italy Indirect techniques - radial velocity measurements 203 planets 175 Planetary systems, 20 systems with > 1 planet 94,4% Doppler Wobble Hot Jupiters mostly

Eva Meyer MPIA-Student-Workshop, Italy Requirements High measurement precision ~ 1m - 20 cm/s Stability over ~ 10 years Derived orbital parameters –P, e, a, T, ω Msini Kürster et al. 2000, A&A 353, L33 RV time series of the young G0V star ι Hor

Eva Meyer MPIA-Student-Workshop, Italy Radial Velocity amplitudes of planets in the solar system PlanetMass [M J ]V [ms -2 ] Mercury1.74 x Venus2.56 x Earth3.15 x Mars3.38 x Jupiter Saturn Uranus Neptune

Eva Meyer MPIA-Student-Workshop, Italy - Astrometry So far 8 planets: –Gl 876: 2 planets –55 Cnc: 4 planets –ε Eri Wobble around center of mass due to planet Law of the lever: Θ s = m p /m s. a p /d Limits: 1-2 mas (ground based) 0.1 mas (HST FGS) need for interferometrie for high precision PRIMA Constraints: nearby stars, not too close to the star can derive inclination and mass of planetary companion

Eva Meyer MPIA-Student-Workshop, Italy What do I observe? I see the overlay of three different motions: –Proper motion

Eva Meyer MPIA-Student-Workshop, Italy What do I observe? I see the overlay of three different motions: –Proper motion –Parallax

Eva Meyer MPIA-Student-Workshop, Italy What do I observe? I see the overlay of three different motions: –Proper motion –Parallax –Planetary signal need to measure all 3 motions accuratly Derived parameters: α, i, Ω, μ, π, T true mass of companion

Eva Meyer MPIA-Student-Workshop, Italy Jupiter as an example For a star at 10 pc distance: SourceDisplacement (mas) Jupiter at 1 AU100 Jupiter at 5 AU500 Jupiter at 0.05 AU5 Neptune at 1 AU6 Earth at 1 AU0.33 Parallax~100 Proper motion (yr -1 )?

Eva Meyer MPIA-Student-Workshop, Italy And what about AO effects? maybe there remains a residual defocus or other distortions one need a reference pattern of background-stars to determine the platescale and changes due to instrumental effects

Eva Meyer MPIA-Student-Workshop, Italy And what about AO effects? maybe there remains a residual defocus or other distortions one need a reference pattern of background-stars to determine the platescale and changes due to instrumental effects but the background-stars can have their own pm and parallax

Eva Meyer MPIA-Student-Workshop, Italy Transits Venustransit June 2004

Eva Meyer MPIA-Student-Workshop, Italy Transits Photometric detection Depth of lightcurve yields planet-radius (~ 1% for Jupiter) Tres-1 HD209458

Eva Meyer MPIA-Student-Workshop, Italy Transit Parameters derived: P, T 0, i ~ 90°, R p /R S Together with the mass of the planet from RV measurements one can derive the density of the planet

Eva Meyer MPIA-Student-Workshop, Italy Microlensing Principle:

Eva Meyer MPIA-Student-Workshop, Italy Microlensing Principle: Magnification due to Star and planet acting as lenses D. Bennett

Eva Meyer MPIA-Student-Workshop, Italy Microlensing Principle: Magnification due to Star and planet acting as lenses First planet: Bond et al. ( )

Eva Meyer MPIA-Student-Workshop, Italy BUT: No way of confirmation Single event Short timescale: hours - days Results: 4 detections as of today

Eva Meyer MPIA-Student-Workshop, Italy