Hugh JonesHugh Jones

Frequency of low-mass exoplanets .. what about

the non-detections?

SIMON O’TOOLE (AAO/HERTFORDSHIRE), CHRIS TINNEY, JEREMY BAILEY, ROB

WITTENMYER (UNSW), PAUL BUTLER (CARNEGIE), BRAD CARTER (SOUTHERN

QUEENSLAND)

Planet mass functionPlanet mass function

Earth Neptune Jupiter

Exoplanet distributionsExoplanet distributions

AAPS (Anglo-Australian Planet AAPS (Anglo-Australian Planet Search)Search)

Nearly 300 nights over last 10 years on 250, V< 7.7 F, G, K, M IV, V stars selected on CaHK and observed with S/N=200 has yielded more than 30 nearby exoplanets (and 18 spectroscopic binaries)

Recent programme of operational upgradesObserving sequencerAutomated iodine cellExposure meter

Near future – fibre feed

Many ‘noise’ componentsMany ‘noise’ componentse.g., asteroseismological e.g., asteroseismological

signalsignal

asteroseismological signal function asteroseismological signal function of L/Mof L/M

Based on Sun, Kjeldsen et al. 2008, Alpha Cen A varies by ~20%

plus ~10% over Solar cycle

Strategy continuous long Strategy continuous long blocks of telescope timeblocks of telescope time

48 night 48 night run on 24 run on 24 bright starsbright stars

ExoplanetsExoplanets

Development of robust Development of robust simulation system for AAPS simulation system for AAPS datadata

Differences between by star-by-Differences between by star-by-star simulations star simulations

Differences between by star-by-Differences between by star-by-star simulations star simulations

DetectabiliDetectability on 48 ty on 48 night runnight run

Detectability sensitive to mass Detectability sensitive to mass functionfunction

0.01 -10 MJ lines of increasing thickness

Mass function dN/dM ~MMass function dN/dM ~M-1-1 (~17% of planets host planets with >3 M(~17% of planets host planets with >3 MEE and <16 days) and <16 days)

ConclusionsConclusions

Simulation system can provide assessment of exoplanetary architectures based on RV data

With multiple telescopes and long campaigns (1m/s precision) can constrain Saturn mass planets out to 6 AUNeptune mass planets out to 1 AUSuper-Earths out to 0.3 AUEarth-mass planets out to 0.1 AU