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Spectroscopic Orbits Of Kepler's Gas Giants KOI-254: A Case Study. John A. Johnson Sebastian Pineda Michael Bottom Zach Gazak Josh Winn Kevin Apps Andrew Howard Geoff Marcy Howard Isaacson. R P > 5 R E arth. KOI-254. KOI-254. Cool: T eff < 4000 K (exact value very uncertain )
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Spectroscopic Orbits Of Kepler's Gas GiantsKOI-254: A Case Study John A. Johnson Sebastian PinedaMichael Bottom Zach Gazak Josh Winn Kevin Apps Andrew Howard Geoff Marcy Howard Isaacson
RP > 5 REarth KOI-254
KOI-254 • Cool: Teff < 4000 K (exact value very uncertain) • Faint: V = 16.9 • R★ = 0.65 R, M★ = 0.53 M • Period = 2.455 days • Transit Depth = 3.6%
Kepler Johnson et al. 2011 in prep RP = ?? NickelLick Obs.
Muirhead et al. (2011) No Main Sequence!
Rojas Ayala et al. (2010) Rojas Ayala et al. (2011 in prep)
Muirhead et al. (2011) On astro-ph NOW!
An Empirical Approach • No reliance on atmosphere or evolution models • Broadly applicable, without need for a parallax
A Photometric Calibration • J,H,K MJ,H,K M★, d(Delfosse et al. 2000) • V - K [Fe/H], M★ (Schlaufman & Laughlin 2010) • r - J MJ M★ (West et al. 2005, Delfosse et al.) • a/R★ M★ (Seager, Mallen-Ornelas 2003) An example: K-band magnitude to Mass, distance
Johnson, Gazak, Apps et al. 2011 in prep Sample of nearby stars with known parallaxes, and hence known M★
Keck Observatory Keck Observatory 400 Massive, Evolved Stars900 Sun-like dwarfs150 Low-mass M dwarfs with an average of 25 observations per star
50 individual spectra Final coadded spectrum
0.25 M 0.45 M M★ = 0.68 M Pseudo- continuum line region DecreasingMass
Bottom, Pineda & Johnson 2011 in prep Increasing Mass
Bottom, Pineda & Johnson 2011 in prep Decreasing [Fe/H]
Bottom, Pineda & Johnson 2011 in prep rms = 8.4%
Photometric x Spectroscopic
KOI-254b Schlaufman & Laughlin (2010) Johnson & Apps (2009)
Thank You Sebastian PinedaMichael Bottom Kevin Apps Zach Gazak Josh Winn Andrew Howard Geoff Marcy Howard Isaacson