Laetitia Delrez (University of Cambridge)

Transcription

1 Laetitia Delrez (University of Cambridge) on behalf of the SPECULOOS team EXOPLANETS II Cambridge 2 July 2018

2 Consortium University of Liege (Belgium): M. Gillon (PI), E. Jehin, A. Burdanov, E. Ducrot, D. Sebastian (Sept. 2018), C. Silva Fernandes, S. Sohy, V. Van Grootel University of Cambridge (UK): D. Queloz, L. Delrez, C. Murray, S. Thompson MIT (USA): J. de Wit King Abdulaziz University (Jeddah, Saudi Arabia): Y. Almleaky University of Bern (Switzerland): B.-O. Demory University of Birmingham (UK): A. Triaud University of California San Diego (USA): A. Burgasser University of Warwick (UK): J. McCormac Cadi Ayyad University (Marrakesh, Morocco): Z. Benkhaldoun, K. Barkaoui Instituto de Astrofísica de Canarias (Tenerife, Spain): R. Alonso, R. Rebolo

3 Ultra-cool dwarfs Nature: mix of very low mass stars and browndwarfs P. Marenfeld & NOAO/AURA/NSF Spectral type: later than M6, including L, T, and Y dwarfs Effective temperature: 2700 K Luminosity: L NASA/IPAC/R. Hurt (SSC) Mass: 0.1 M Radius: ~ R M-dwarf L-dwarf T-dwarf

4 Why a transit survey targeting ultra-cool dwarfs? 1. Significant fraction of the Galactic population RECONS 10 pc sample solar-type stars ultra-cool dwarfs 10-15% of the population in the solar neighborhood

5 Why a transit survey targeting ultra-cool dwarfs? 2. Nearly uncharted territory NASA Exoplanet Archive Ultra-cool dwarfs MEarth K2 NGTS TESS PLATO Planetary formation models and statistics predict a population of low-mass planets around UCDs

6 Why a transit survey targeting ultra-cool dwarfs? 3. Transits of Earth-sized planets are deep and detectable from the ground G2V 1R M8V 0.11R Transit depth ~ 1% Transit depth ~ 0.01% ESO

7 Why a transit survey targeting ultra-cool dwarfs? 4. Habitable zone is very close to the host G2V 1L L2V L a = 0.75 to 1.76 AU P = 235 to 850 d Prob. transit = 0.6 to 0.25 % a = to AU P = 1 to 5 d Prob. transit = 4.5 to 1.6 % HZ limits from Kopparapu+ (2013) optimistic case Transits of potentially habitable planets are more likely and frequent

8 Why a transit survey targeting ultra-cool dwarfs? 5. Atmospheric characterization of HZ Earth-sized planets is possible JWST Significance of a spectral feature in transmission NASA E-ELT U C D s ESO Best targets = nearest and brightest UCDs de Wit & Seager (2013)

9 Target sample ~1200 brightest (K-mag 12.5) ultra-cool dwarfs Main goal of SPECULOOS: Probe with 70% efficiency their HZ for transiting planets of Earth-size and below

10 General concept Targets spread all over the sky Short transits (down to 15 min) Efficient exploration of the habitable zone Targets SED peaks in the near/mid-ir Ability to detect single transits on our targets Targeted survey Continuous monitoring Monitoring duration optimized for each target (10-20 nights) Near-IR optimized CCDs 1-m class telescopes Two observatories of 4 1-m telescopes (one in each hemisphere) Survey completed within ~10 years ASTELCO

11 Prototype on TRAPPIST-South 0.6-m robotic telescope with a near-ir optimized CCD camera at La Silla (Chile) Targets: ~50 brightest southern ultra-cool dwarfs (mean K-mag = 9.7) Goal: >100 hrs per target to assess photometric precision and detection potential

12 Prototype on TRAPPIST-South TRAPPIST-1 (aka SPECULOOS-1) NASA/JPL-Caltech See talks by B.-O. Demory (Wednesday 09:30) and M. Gillon (Thursday 10:00) + poster by E. Ducrot (PhD student Liege)

13 A global network of robotic telescopes SPECULOOS-North Teide, Tenerife SPECULOOS-South Paranal, Chile

14 The SPECULOOS Southern Observatory 4 1-m robotic telescopes at Paranal (Chile) Collaboration: Liege / Cambridge / Jeddah Funding: ERC / Simons Foundation / MERAC/ Jeddah / Cambridge / Liege VLT+VLTI+VST VISTA NGTS SPECULOOS SOUTHERN OBSERVATORY

15 The SPECULOOS Southern Observatory P. Aniol P. Aniol 3 telescopes operational - commissioning of the 4th one in the coming weeks

16 The SPECULOOS Southern Observatory Optical system (ASTELCO) - 1-m Ritchey-Chretien with F/8 focal ratio - raw aluminium coating Equatorial mount NTM-1000 (ASTELCO) - direct drive system - speed: up to 20 /s - pointing accuracy: ~5 - tracking accuracy: ~1 over 10 min Near-IR optimized CCD camera (Andor ikon-l) - deeply depleted 2K 2K e2v chip - FOV and plate scale: and 0.35 /pix - 5-stage Peltier cooling (-70 C) - QE: peak of 94% at 740 nm - fringe suppression 10-slots filter wheel (FLI) - Sloan-g, -r, -i, -z - special filters I+z and blue-blocking

17 The SPECULOOS Southern Observatory Detection potential Synthetic transits of an Earth-sized planet in the habitable zone Detection significance Detection limit (5-σ) 12-σ 14-σ 17-σ 0.68 R 0.65 R 0.57 R

18 The SPECULOOS Southern Observatory Photometric performance Transit of TRAPPIST-1e observed simultaneously with 2 telescopes: Detection significance: 10-σ RMS: 770 ppm / 7.2min Combined light curve: Detection significance: 14-σ RMS: 530 ppm / 7.2min See also poster by C. Murray (PhD student Cambridge)

19 The SPECULOOS Northern Observatory 4 1-m robotic telescopes at Teide Observatory (Tenerife) Collaboration: MIT / Liege / Jeddah / IAC Funding: Heising-Simons Foundation / Liege / Jeddah / private sponsors 2 of 4 telescopes funded Installation: 1 st telescope in December 2018

20 A global network of robotic telescopes SPECULOOS-North Teide, Tenerife TRAPPIST-North Oukaïmeden, Morocco TRAPPIST-South La Silla, Chile SPECULOOS-South Paranal, Chile

21 The TRAPPIST telescopes SOUTH 0.6-m telescope at La Silla (Chile) Collaboration: Liege / Geneva Funding: BelgianF.R.S.-FNRS, Swiss NSF NORTH 0.6-m telescope at Oukaïmeden (Morocco) Collaboration: Liege / Marrakesh Funding: Liege ~100 brightest targets

22 A global network of robotic telescopes SAINT-EX San Pedro Mártir, Mexico SPECULOOS-North Teide, Tenerife TRAPPIST-North Oukaïmeden, Morocco TRAPPIST-South La Silla, Chile SPECULOOS-South Paranal, Chile

23 SAINT-EX 1-m robotic telescope at the National Astronomical Observatory of Mexico Collaboration: Bern (PI: B.-O. Demory) / Mexico / Cambridge / Geneva Installation: August 2018 ~50% time on SPECULOOS

24 On astro-ph today

25 Trappist beers and speculoos biscuits Belgian products Beers brewed within the walls of a Trappist monastery (branch of the Cistercian Order) Spiced shortcrust biscuit traditionally baked for St Nicholas day (Dec 6)