Ground based Transit surveys of Giant Planets: past successes and - PowerPoint PPT Presentation

Ground based Transit surveys of Giant Planets: past successes and future challenges Don Pollacco (Warwick University, UK) OHP October 2015

Outine First detections The dark years Classical wide angle surveys and their successes (a personal view) More specialized surveys – late type stars (and smaller planets) - Bright stars as planet hosts New toys Ground based surveys in the era of TESS 2

History: First Detections 3

The scene in 2001 4 Horne 2003

History Prior to September 2006 we had ~10 TEPs! HATN-1b September 2006 (Bakos et al) 14 TEP’s known when WASP-1b/2b October 2007 (Collier Cameron et al) 5

Successful “classical” programs Programs that have discovered TEP’s include: HATNET OGLE QATAR TRES WASP XO 6

Successful “classical” programs HATNET Programs that have discovered TEP’s include: HATNET 56 Planets OGLE QATAR TRES WASP XO Multi station Including HATN-11b, 13b, 2b Many interesting objects Excellent survey 7

Successful “classical” programs OGLE Programs that have discovered TEP’s include: HATNET 56 Planets OGLE 8 Planets QATAR TRES WASP XO Not actually an ESP facility but designed For similar measurements and 1.2x1.2deg fov. Includes OGLE-TR-56b – very short period Planet, microlensing planets 8

Successful “classical” programs QATAR Programs that have discovered TEP’s include: HATNET 56 Planets OGLE 8 Planets QATAR 2 Planets TRES WASP XO Fainter, redder targets but see later…. 9

Successful “classical” programs Programs that have discovered TEP’s include: HATNET 56 Planets OGLE 8 Planets QATAR 2 Planets TRES 5 Planets + HD209458b WASP XO TRES Included STARE Pioneering survey 10

Successful “classical” programs WASP Programs that have discovered TEP’s include: HATNET 56 Planets OGLE 8 Planets QATAR 2 Planets TRES 5 Planets + HD209458b WASP 106 Planets XO Factory TEP discovery Many people in the audience involved to some extent WASP-12b/17b/33b etc 11

Successful “classical” programs XO Programs that have discovered TEP’s include: HATNET 56 Planets OGLE 8 Planets QATAR 2 Planets TRES 5 Planets + HD209458b WASP 106 Planets XO 5 Planets XO-2 – wide binary with gas giants orbiting each component 12

Current situation All surveys sensitive to sun-like stars About 230 TEP have Δ m & Δ r <10% (encyclopedia shows 1225 TEPs, 20151005) Vast majority from ground based surveys – but shouldn’t be too surprised as these are the easiest to measure – mass well suited to current instruments HATNET WASP Performance seems similar for both surveys. Note sensitivity to high mass planets. HATNET better sensitivity to longer period candid 13

HATNET WASP Some HATNET and WASP candidates with periods upto 50-60 days. 14

Successes 1) Diversity and Inflation 15

Successes Eg WASP-12b Fossati et al 2010 1) Diversity and Inflation 2) Evaporation 16

Successes 1) Diversity and Inflation 2) Evaporation 3) RMs and scattering/migration 17

Successes 1) Diversity and Inflation 2) Evaporation 3) RMs and scattering/migration 4) Long period massive companions 18 HAT-P-13b/c Bakos et al

Successes 1) Diversity and Inflation 2) Evaporation 3) RMs and scattering/migration 4) Long period massive companions 5) Terrestrial companions Becker et al 19

Successes 1) Diversity and Inflation 2) Evaporation 3) RMs and scattering/migration 4) Long period massive companions 5) Terrestrial companions 6) Atmospheres: clouds etc Sing et al 20

Improvements to SWASP (WASP-S currently WASP-115b 5mmag eclipse – not fully surveying extremely wide convinced it’s a planet yet but will be beyond fields) reasonable doubt over the next few days. McCormac et al Stabilized focus Several years of data Original Stabiized currently being reduced. Other fun targets coming: WASP-150b 5mmag, 7.7Mj , R~0.3-0.4Rj Δ Mj, Δ Rj < 21 10%, e~0.4

Push to smaller stars: MEarth First pointed survey. Telescopes with smart observational strategy. Targets one at a time. Designed to look at M dwarfs (aiming for M5) Science Driver: small planets in the HZ. GJ1214b single discovery (actually another one coming I think) Probably the brightest one in the (well V=14 th mag) northern sky 22

Push to smaller stars: APACHE Pointed survey - similar to Mearth 40cm telescopes No TEP yet 23

Push towards small stars: HATS Another excellent survey from Bakos et al 3 sites: Chile, Namibia, Australia, operational since 2010 Smaller fov, fainter stars 12 Planets So far highlight is HATS-7b (Bakos et al), 8b (Baylis et al) - Super-Neptunes Depths are 0.5-1%. HATNET/WASP have few similar depth objects 24

Push to brighter stars: KELT KELT – operational for a few years Extremely large field. Should be looking For V=6-9 mag host stars. KELT-N/S has 8 planets 25

Push to brighter stars: MASCARA MASCARA (Ignas Snellen) first unit running on La Palma for about a year. Sensitivity V=4-8 mag. Recovery of HD189733 (V=7.7) 26 Stationary cameras

Pushing towards smaller stars (and planets): Qatar 2 The new Qatar survey. Now using 20cm aperture, focus stabilized astrographs Multi site USA, Tenerife, China Rolling out now, first planets will be soon. Optimized for redder stars 27

Pushing towards smaller Planets: NGTS Designed from the beginning to go to the next “level” – routine detection of Neptunes and potentially smaller planets Astrographs + deep depleted detectors => red sensitive and will be highly stable. Field coverage needs an array of telescopes (12 telescope array similar fov to Kepler). Prototypes on La Palma, Geneva (right) NGTS built on Paranal 28

Transit discovery space NGTS Updated from Wheatley et al. 2014 Data: exoplanets.org

12 x 20cm f/2.8 telescopes independent mounts back-illuminated, deep-depletion CCDs 100 sqr deg total FoV; 5 arcsec pixels Peter NGTS at the Paranal Observatory in Chile Wheatley

Amp ≈ 1mmag 3min cadence Tom Louden 04/10/2015 EWASS 2015 31

NGTS currently 4/12 units running, 31/10 expect 8/12, and full survey end of the year WASP-4b

Future Challenges Until TESS, ground based transit surveys will continue to find significant numbers of characterisable planets. After the TESS launch their role will change. While most of the sky will be surveyed by TESS the visits will be less than 1month (at least initially). We may expect many single transit events in dataset. We will need a (photometric) capability to – follow-up single transit events with instruments capable of producing accurate measurements cheaply for period determination - follow-up the many systems that will have only 2-3 transits and needing period improvement - Extended coverage of hosts stars for activity monitoring So continued work for many facilities and their data archives. HAT team confident enough to be building a new facility HATPI – capable of monitoring entire sky every 30sec…. 63 separate optical units… 33

Summary The ability to determine accurate M & R for planets discovered by ground based transit surveys has led to much of our understanding of this class of planet. Surveys have evolved from “general purpose” to more specialized. TESS will be an important part to the story but if the ground based facilities do not continue much of its work will remain unfinished. 34