Planets Orbiting M Stars Ian Crossfield Sagan Fellow, UA/LPL 2015/11/02 Collaborators: K. Aller, T. Barman, C. Beichman, B. Benneke, J. Christiansen, D. Ciardi, S. Ciceri, J. Crepp, D. Dragomir, C. Dressing, BJ Fulton, T. Greene, B. Hansen, Th. Henning, A. Howard, H. Isaacson, H. Knutson, J. Krick, S. Lepine, M. Liu, J. Livingstone, L. Mancini, A. Martinez, T. Morton, C. Obermeier, E. Petigura, J. Schlieder, E. Sinukoff, M. Werner K2's M Dwarf Systems 2015/11/01

Why Target M Dwarfs? Increase the number of known M dwarf planetary systems; Measure M dwarf planet frequencies vs. planetary and stellar properties; Constrain models of planetary interiors and atmospheres; Find planets in their stars’ habitable zones; and Find targets for atmospheric studies with HST & JWST. K2's M Dwarf Systems 2015/11/01

Planet frequency increases toward smaller and cooler planets: (for both M stars & FGKs) RARE Dressing+2013, 2015, Howard+2012, Petigura+2013a,b K2's M Dwarf Systems 2015/11/01 C MMON?

Half of all stars are less than ½ a solar mass K2's M Dwarf Systems 2015/11/01

Small planets occur 2–3x more frequently around cooler stars: Mulders+2014 See Gijs Mulders' talk on Wednesday

But: only ~5% of confirmed transiting planets orbit M dwarfs!

K2's M dwarf advantage: Targeting more M dwarfs Kepler (slide from D. Huber)

K2's M dwarf advantage: M dwarf Habitable Systems `Habitable Zone'

K2's M dwarf advantage: M dwarf Habitable Systems `Habitable Zone' K2's M dwarf “sweet spot”

M dwarf advantage: cooler stars & planets probe interior models at lower temperatures: All planets w/ >4σ M & R: (figure by E. Sinukoff)

M dwarf advantage: cooler stars & planets probe interior models at lower temperatures: Cool planets w/ >4σ M & R: (figure by E. Sinukoff)

Small M dwarfs are the best targets for transmission spectroscopy to probe exo-atmospheric makeup: λ1 Flux Time λ2 C-H stretch CH4 CH4 Tp µP ρp R*2 signal ~ C2H2 CO Robinson+2014

Transiting Target Timeline HST Operations 2015 2016 2017 2018 2019 2020 K2's M Dwarf Systems 2015/11/01

Transiting Target Timeline HST Operations 2015 2016 2017 2018 2019 2020 } Launch, check-out, Cycle 1 K2's M Dwarf Systems 2015/11/01

Transiting Target Timeline HST Operations 2015 2016 2017 2018 2019 2020 } Calls for GTO, ESR, Cycle 1 Proposals } Launch, check-out, Cycle 1 K2's M Dwarf Systems 2015/11/01

Transiting Target Timeline HST Operations 2015 2016 2017 2018 2019 2020 } Calls for GTO, ESR, Cycle 1 Proposals TESS operations } Launch, check-out, Cycle 1 K2's M Dwarf Systems 2015/11/01

Transiting Target Timeline { HST Operations 2015 2016 2017 2018 2019 2020 K2 } Calls for GTO, ESR, Cycle 1 Proposals TESS operations } Launch, check-out, Cycle 1 K2's M Dwarf Systems 2015/11/01

So... what have we found? K2's M Dwarf Systems 2015/11/01

Our team has found ~150 planet candidates in C0-C4 size ~ planet radius K2's M Dwarf Systems 2015/11/01

M dwarf planet candidate population: sensitivity dropoff See poster by Arturo Martinez K2's M Dwarf Systems 2015/11/01

Planet Size vs. Stellar Magnitude FGK stars M dwarfs GJ1214 K2's M Dwarf Systems 2015/11/01

Adaptive Optics Followup Imaging from: Keck/NIRC2 LBT/LMIRCam Gemini/NIRI Hale/PHARO RoboAO We have followup imaging for ~all C0-4 planet candidates... K2's M Dwarf Systems 2015/11/01

NIR spectra: IRTF/SpeX ~0.8—2.4 µm (C. Dressing, J. Schlieder, K. Aller) See Josh Schlieder's talk on Wednesday Schlieder et al., submitted K2's M Dwarf Systems 2015/11/01

optical spectra: NTT/EFOSC 0.6—0.95 µm (S. Ciceri, C. Obermeier, I. Crossfield) Spectra in hand for ~all K2 M dwarf candidates K2's M Dwarf Systems 2015/11/01

NIR spectra: NTT/SOFI R ~ 1000, ~0.9—2.4 µm A. Martinez, S. Ciceri, C. Obermeier, I. Crossfield See poster by Arturo Martinez Spectra in hand for ~all K2 M dwarf candidates Martinez et al., in prep. K2's M Dwarf Systems 2015/11/01

Spectral Types of K2's M dwarf planet candidate systems: Spectral types of candidates in C0-3: K2's M Dwarf Systems 2015/11/01

Preliminary stellar parameters: Stellar Radius K2's M Dwarf Systems 2015/11/01

A few multi-planet M systems per K2 field K2-3bcd (Crossfield et al. 15) ~1.9 RE ~2.3 RE K2-5bc (Montet et al. 15) ~1.5 RE ~2.0 RE C3 multi... See Evan Sinukoff's talk on Wednesday Several more in C4... K2's M Dwarf Systems 2015/11/01

Photoeccentric Effect: reveals several planets on eccentric orbits P ~ few days e > 0.2 M dwarf host See Josh Schlieder's talk on Wednesday 0.5 1.0 1.0 180 360 eccentricity omega K2's M Dwarf Systems 2015/11/01 omega

Habitability Index for Transiting Exoplanets K2-3d K2-3d K2-18b simulated TESS yield K2-18b Barnes+2015 Montet+2015 Crossfield+2015 K2's M Dwarf Systems 2015/11/01 Habitability Index Habitability Index Stellar Insolation

Transiting Target Timeline { 2015 2016 2017 2018 2019 2020 K2 } JWST Calls for GTO & Cycle 1 Proposals } TESS operations JWST Launch K2's M Dwarf Systems 2015/11/01

JWST (and HST) targets are already here: K2-3b: one 1-11 µm transit spectrum would easily distinguish atmospheric makeup Greene et al., submitted

JWST (and HST) targets are already here: 1.5 RE, ~300 K 2.2 RE, ~270 K Being observed in HST GO-13665 & Spitzer GO-12081 (PI: Benneke) simulated data

K2 candiates require additional transits to refine timing: Transit surveys measure Uncertainty in transit time grows with time K2's M Dwarf Systems 2015/11/01

K2 candiates require additional transits to refine timing: Transit surveys measure Uncertainty in transit time grows with time ? ? (today) (2019) ? K2's M Dwarf Systems 2015/11/01

K2 candiates require additional transits to refine timing: Transit surveys measure Uncertainty in transit time grows with time ? ? (today) (2019) ? For K2-3d: σP = 8.5 min In mid-2019: timing uncertainty is ±6 hr (1σ) Pre-JWST transit followup is essential to maximize science return! See Dan Bayliss' talk on Wednesday K2's M Dwarf Systems 2015/11/01

Spitzer transits are underway to ensure precise ephemerides in the JWST era: (two transits of K2-3b) Beichman et al., in prep. K2's M Dwarf Systems 2015/11/01

RV spectroscopy already measuring masses for K2's M dwarf systems: Cool planets w/ >4σ M & R: K2-3b (Alemenara et al. 2015) (figure by E. Sinukoff)

Take-home Points: K2 is finding lots of exciting M dwarf planet candidates! (….. maybe fewer than expected?) Validation & follow-up ongoing O+IR spectra reveal stellar parameters We're finding new planets that are Temperate, Earth-sized; Good RV targets (for masses) Good HST/JWST targets (for atmospheres) K2's M Dwarf Systems 2015/11/01

K2's M Dwarf Systems 2015/11/01

Looking for Hidden Giants: Probable M giant K2's M Dwarf Systems 2015/11/01

K2 M Dwarf Advantage: Numbers Kepler sample (Dressing et al. 2015): 2543 stars (all observed for ≥ 1000 days) Most have T eff ≥ 3500 K, R ≥ 0.4 R sun 157 planet candidates K2: Observing ~ 5000 M dwarfs per field ≥ 10 fields, ~ 80 days each The K2 M dwarf advantage: 5000*80*10 / 2543*1000*1 ~ 1.5x

TESS K2 Kepler Temporal coverage Sky coverage K2 sky coverage 2017-2019 K2 2014-2017 Kepler 2009-2014 Temporal coverage K2's M Dwarf Systems 2015/11/01 Sky coverage

Expected yields: K2 and TESS K2 yield to date (4 of 14 fields)

Expected yields: K2 and TESS K2 yield to date (4 of 14 fields) TESS yield: Ashley Wilkins; Sullivan+2015