The SPIRou RV surveys. Étienne Artigau for the SPIRou collaboration

Transcription

1 + The SPIRou RV surveys Étienne Artigau for the SPIRou collaboration

2 + SPIRou RV surveys n Two major surveys n Blind survey of selected stars n Very deep survey of nearest M dwarfs n Down to ~1 M earth in the Habitable Zone (HZ) n Preparing the ELT era n Follow-up of transits n TESS, K2 n Ground-based surveys

3 + Goal : find the habitable planets closest to us!

4 + Goal : find the habitable planets closest to us!

5 + Goal : find the habitable planets closest to us! n Nearby è M dwarfs n Nearby è need to include some mildly active Ms n Activity filtering is key n Habitable è ~1 M earth n Most-likely in multiplanet system n Lost of visits:

6 + Blind survey n Major discussion point for this week s SPIRou meeting n How many stars, how many visits per star? n SNR is only part of the story n Lots of degrees of freedom to fit! n Properly monitor stellar activity n Spectropolarimetry gives SPIRou a significant edge n E. Hebrard demonstrated 2-3-fold diminution of activity jitter through spectropolarimetry (HARPS-pol & Narval) n Paper submitted

7 + n For periods <50 days n 0.57 Earth-sized planet/star n 0.51 Super-Earth/star n Dressing & Charbonneau 2015

8 + Blind survey n Evolution of the blind survey science case since 2009 n >300 stars, mostly geared towards establishing the abundance of HZ terrestrial planets around Ms n Planet occurrence around early-ms is now relatively well known n Take advantage of Kepler+K2 results n M dwarf planets are very common n Argues for a smaller sample n Be complementary with TESS n Later-type dwarfs n Kepler/K2/TESS mostly sensitive up to ~M4 n Pave to road to TMT/E-ELT direct imaging of terrestrial planets

9 + Blind survey 10 Planet mass (M earth ) Planet effective temperature (K)

10 + Blind survey Starshade Contrast 10 7 SPHERE ZIMPOL 2 hr Contrast (mag) 10 8 PCS E ELT Detected Detected and HZ Detected and transits PCS E ELT Separation (arcsec) 22 24

11 + Blind survey n Crossfield 2016

12 + Blind survey Very nearby Ms Few, if any, detectable planet around G2 stars n Crossfield 2016

13 + Transit follow-ups n Kepler n Most transit host stars are faint n K2 n Series of fields along the ecliptic n ~80 day monitoring n TESS n Nearly all sky n Will find the bright transit host stars n for <28 day orbits n... not too shallow n 2017 launch n Data publicly available n Need a fast turnaround time n Expert Kepler planet-finder now in SPIRou team

14 + Transit follow-ups Ricker 2014

15 + Transit follow-ups

16 + Transit follow-ups ~2m/s HARPS 1/4h

17 + Transit follow-ups SPIRou~2m/s 1/4h

18 + Transit follow-ups n Transits only provide radius ratios Marcy 2014 Ultra-dense rocky? Mini gas «giants»? n Near-Earth-radius planets are surprisingly diverse n Mass measurements are required to contrain physical nature n Expect some serious oddbals: >15 g/cm 3 and <1 g/cm 3 n Expect the unexpected! n Transiting planets will be more distant than the best direct imaging targets n 10-30pc compared to <5-10pc n No significant target overlap between the two surveys

19 + Transit follow-up n Necessary step before atmospheric characterization n JWST n NIRISS optimized for high SNR transit spectroscopy n µm n R~1000 n Ground-based follow-ups n Very high-resolution transit spectroscopy n Winds n Brightest targets with SPIRou? n Earth-sized with ELTs

20 + Transit follow-up n Probing the atmosphere of Earth-like planets with JWST 0 Transit Depth = 2102 ppm n Dream target! Transmission Spectrum (ppm) O 2 H 2 O O2 H 2 O Model Order 1 Order 2 Saturated CO 2 H2O CO 2 CH 4 JMAG = 8.10 NREAD = 2 SUB-ARRAY = 256x2048 Elapsed Clock Time = h Wavelength (nanometers) H 2 O CO 2 CO 2 n Earth-like planet n Brightness limit n Detects n Oxygen n Water n CO 2

21 + Transit follow-up n Probing the atmosphere of Earth-like planets with JWST 0 Transit Depth = 2102 ppm n Dream target! Transmission Spectrum (ppm) O 2 H 2 O O2 H 2 O CO h of JWST you ll have to carefully pick your target! Model Order 1 Order 2 Saturated H2O CO 2 CH 4 JMAG = 8.10 NREAD = 2 SUB-ARRAY = 256x2048 Elapsed Clock Time = h Wavelength (nanometers) H 2 O CO 2 CO 2 n Earth-like planet n Brightness limit n Detects n Oxygen n Water n CO 2

22 + Transit follow-up n Ground-based surveys of later-ms n Check yesterday s CNN headlines! M8

23 + Transit follow-up n Ground-based surveys of later-ms n Check yesterday s CNN headlines! 1.5 day 130 C 1.1 R earth 2.4 day 70 C 1.0 R earth 9-18 days -30 C 1.1 R earth M8

24 + Transit follow-up n Ground-based surveys of later-ms n Check yesterday s CNN headlines! 1.5 day 130 C 1.1 R earth 2.4 day 70 C 1.0 R earth 9-18 days -30 C 1.1 R earth M8 n 31 M7-M9 within 14 pc n Geometric transit likelihood : 1/20 to 1/30 n The majority of late-ms must have similar systems!

25 + Transit follow-up

26 + Transit follow-up