Transcript sept2302
Astrobiology related science at STScI Solar system observations HST and planetary transits HD 209458 – discovered by Keck/Geneva RV teams - transit detected by Charbonneau et al (2000) using ground-based photometry HST data provide unparallelled photometric accuracy STScI and transit surveys Kepler – photometric survey of 105 solar-type stars in Cygnus search for transits by jovian and terrestrial planets HST and planetary masses All current planetary-mass companions have been identified based on radial velocity variations. orbital inclination not known, so we can only derive M sin(i) Are they really planetary-mass objects? HST can provide the precision astrometry required to determine i Positional residuals < 0.3 mas set upper limit of 30 MJ Coronography with HST NICMOS: IR dusty disks around nearby stars Ring-like structures probably indicate the presence of planetary-mass bodies Coronography with HST • ACS Stellar Coronograph – high contrast imaging Flux Arcsec -2 (relative to total stellar flux) – planets/low mass stars – dust disks – galaxies around quasars 10 -2 1.8" Spot Azimuthal Median Profiles F435W F814W 10-4 Direct (no coronagraph) 10-6 Coronagraph only 10-8 Coronagraph - star 10 -10 Sparks, Clampin 0 2 4 Arcsec 6 8 Coronography: The next step Jovian Planet Finder: Clampin et al TPF: R. Brown et al Optical coronography Brown dwarfs at STScI Brown dwarfs serve as a bridge to studying atmospheres of giant planets High spatial resolution permits identification of low-mass binaries 2M0850+1057 60 MJ + 55 MJ The Galactic distribution What parameters drive planet formation? Metallicity 1. No planets detected in 47 Tucanae 2. Clear preference for high metallicities amongst known systems James Webb ST Three science instruments: 1. MIRI – mid-infrared imaging and spectroscopy 5 28 m Protostellar disks, planet formation 2. NIRCAM – near-infrared imaging, 0.6 5 m brown dwarfs, low-mass companions 3. NIRSPEC – near-infrared spectroscopy, 0.6 5 m low temperature atmospheric parameters