Transits from Space: 1. The CoRoT mission

1. Transits from Space: 1. The CoRoT mission

2. Why do Transit searches from Space? • No scintillation noise → One can reach the photon limit • No atmospheric extinction → Less false positives • Continous temporal coverage → if a stars shows a transit you will find it! In short: the light curves are of better quality, have better temporal coverage so you can find smaller transits and transits in long period orbits

3. Disadvantages of Space • If the launch fails you do not get a second chance • If your instrument breaks, you cannot fix it • Space environment introduces different problems in the light curve analysis • It is expensive!

4. The CoRoT Mission (CNES) COnvectionROtationand PlanetaryTransits • Goals: exoplanets + astroseismology • Polar Earth orbit • 27 cm Telescope w/ 4 CCD detectors • 2.8° x 2.8° field-of-view • Max 150 days observing runs • Launched: 27th December 2006 • Participation from: F, A, B, D, E, ESA, Brasil • Duration 6+ years

5. 630 kg + 1000 kg water CoRoT was successfully launched from Baikanur on 27 December 2006

6. Washington, D.C. The Launch Profile of CoRoT: orbit if (WWIII) then White House., U.S.A else if (corot) then orbit end if Baikanur.

7. The Orbit of CoRoT Goal Reality • a = 7278.189 km • e = 0.00162 • i = 90.002 • Porb = 6176–6195 s • a = 7278.475 km • e = 0.00169 • i = 89.984 → The orbit is nearly perfect

8. The eyes of CoRoT Movie time!

9. CoRoT-Mission: Focal Plane Focal Plane: Seismo field: ~10 targets/CCD 5 < V < 9.5 Exofield field: ~ 6000 targets/CCD11 < V < 16 PSF: Astroseismology 2.8o x 1.4o PSF: exo-Planet

10. Exofield Information • CoRoT does not download the entire CCD images, but only the data in an aperture centered on the star • 32 sec integrations. On-board summing of data in aperture plus binning to 512 s exposure time. On-board processing returns only integrated flux in aperture. • 400 „oversampled“ apertures with 32 s sampling. This can be changed during the run • ~ 40 imagettes. Data from the full image inside the aperture is sent back • Chromatic information (CoRoT r,g,b) for only about ½ of the brightest stars (chromatic and monochromatic light curves) • ~6000 apertures per exo-CCD. If more stars are in the field one has to decide before which stars to observed (proposals)

11. Duty Cycle: Not completely continuous coverage The South Atlantic Anomaly (SAA) • ~ 6% of the data is lost due to the SAA • other „random events“ cause 1-2% loss • Duty cycle ~ 92%

12. Sample Light Curves from the Exofield Showing Stellar Variability

13. So is all this effort worth going to Space? An OGLE transit discovery (ground-based) A CoRoT transit discovery

14. The CoRoT Ground-based Follow-up Effort CoRoT only finds transit „candidates“. An extensive ground-based effort is required to confirm that this is indeed a planet. For Space-based transit searches, Ground-based observations are „part of the Mission“ But before the ground-based follow up starts one needs to do the best possible analysis on the light curve to give the best candidates. Much information comes from the light curves e.g.: Is the transit too long : probably a giant Do you see a secondary? Probably an eclipsing binary

15. Problem : The size of the CoRoT aperture The CoRoT PSF can have up to 0-20 background stars whose light contaminates the light of the primary star. The first step is to identify which star is making the transit We will go through the necessary procedures to confirm the planet for the case of CoRoT-7b!

16. Status of CoRoT • CoRoT has been operating for over 4 years • Over 110,000 stars have been observed • 24 Transiting Planets have been discovered • CoRoT mission has been extended for 3 years until the end of 2013 • On 7 March 2009 CoRoT lost DPU1 (Data Processing Unit) that controlled one Exoplanet and one Seismo CCD. CoRoT continues to work well, but only getting data on ½ the original number of stars On 6 March 2009 NASA Launched Kepler

17. P: 4.2568 days R: 1.01 RJ m: 21.66 MJ r: 26.4 cgs P: 1.5089557 days R: 1.49 RJ m: 1.03 MJ r: 0.38 cgs P: 1.742996 days R: 1.465 RJ m: 3.31 MJ r: 1.3 cgs CoRoT-4b CoRoT-3b P: 9.20205 days R: 1.19 RJ m: 0.72 MJ r: 0.5 cgs P: 4.0384 days R: 1.28 RJ m: 0.459 MJ r: 0.22 cgs P: 8.88 days R: 1.15 RJ m: 3.3 MJ r: 2.3 cgs Agrain et al. and Moutou et al. 2008 The first six CoRoT planets: CoRoT-1b CoRoT-2b Barge et al. 2008 Alonso et al. 2008 Deleuil et al. 2008 CoRoT-6b CoRoT-5b Rauer et al., A&A 2009 Fridlund et al., A&A 2009

18. P: 6.2 days R: 0.57 RJ m: 0.22 MJ r : 1.6 cgs P: 0.85 days R: 0.14 RJ m: 0.02 MJ r: 10.1 cgs P: 95 days R: 1.05 RJ m: 0.84 MJ r: 0.9 cgs P: 13.2 days R: 0.97 RJ m: 2.75 MJ r : 3.7 cgs P: 3.0 days R: 1.43 RJ m: 2.33 MJ r : 1.0 cgs P: 2.8 days R: 1.44 RJ m: 0.91 MJ r : 0.8 cgs And the next 6 CoRoT-7b CoRoT-8b CoRoT-9b Barge et al. 2008 Borde et al. 2010 Deleuil et al. 2008 CoRoT-11b CoRoT-10b CoRoT-12b Gillon et al. 2010 Bonnono et al. 2010 Gandolfi et al. 2010

19. P: 4.0 days R:0.88 RJ m: 1.31 MJ r: 2.3 cgs P: 1.5 days R: 1.1 RJ m: 7.6 MJ r : 7.3 cgs P: 3.1 days R: 1.12 RJ m: 63 MJ r: 59 cgs CoRoT-13b CoRoT-14b CoRoT-15b Bouchy et al. 2011 Cabrera et al. 2011 Tingley et al. 2011 In preparation: CoRoT-16b – 24b

20. CoRoT-1b and its Rossiter-McLaughlin effect RM anomaly

21. CoRoT-2b : A Hot Jupiter around an active star P: 1.742996 days R: 1.465 RJ m: 3.31 MJ r: 1.3 cgs Alonso et al. 2008

22. CoRoT-3b : The First Transiting Brown Dwarf P: 4.2568 days R: 1.01 RJ m: 21.66 MJ r: 26.4 cgs

23. Planets Pressure support provided by electron degeneracy pressure, no fusion (M < 13 MJup) Stars Hydrogen fusing in hydrostatic equilibrium (M > 80 MJup) Brown Dwarfs Pressure support provided by electron degeneracy pressure, short period of deuterium burning (13 < M < 80 MJup)

24. CoRoT-1b OGLE-TR-133b CoRoT-3b CoRoT-3b : Radius = Jupiter, Mass = 21.6 Jupiter CoRoT-1b : Radius = 1.5 Jupiter, Mass = 1 Jupiter OGLE-TR-133b: Radius = 1.33 Jupiter, Mass = 85 Jupiter Modified From H. Rauer

25. CoRoT-9b, the first well-known temperate exoplanet • CoRoT-9b: • - R = 1.05 RJ • - P = 95.274 d • - a = 0.407 AU • e = 0.11 • m = 0.84 MJ • - Density = 0.9 gm cm–3 • - Teff = 250 – 400 K Deeg et al., Nature 2010 - longest period planet detected by transits (at time of announcement) - moderate temperate gas giant - low eccentricity, thus moderate temparature variations along orbit

26. CoRoT-7b : The Crown Jewel of CoRoT In spite of rotational modulation due to spots with a photometric amplitude of ~2% one can find…

27. 0.035% CoRoT-7b : The Crown Jewel of CoRoT Transit Curve CoRoT-7b: - Rpl = 1.6 R - P = 0.8536 d - a = 0.017 AU - m = 7.4 MEarth Leger et al., 2009; Queloz et al. 2009, Hatzes et al. 2010

28. The „Sherlock Holmes Proof“ Or why we knew CoRoT-7b was a planet before we had radial velocity measurements. Hypothesis #1: The transit is caused by a contaminant On-off photometry established that nearby stars could not account for transit depth of CoRoT-7

29. Hypothesis #2: The star is really a giant star No, it is a G8 Main Sequence Star

30. Hypothesis #3: There is a faint very nearby background eclipsing binary star that causes the eclipse Adaptive Optics Imaging shows no very close companions

31. Hypothesis #4: A Hiearchical Triple system with 2 eclipsing M-dwarfs, Short period M dwarfs are very active and we would have seen Ca II emission from the binary stars and X-ray emission

32. Hypothesis #5:The transit is caused by a background (or binary companion) M dwarf with a transiting Hot Jupiter 1. Giant planets to M dwarfs are rare 2 The M dwarf is bright in the Infrared. High resolution infrared spectral observations show no evidence for an M dwarf companion.

33. There are only two astronomical bodies that have a radius ~ 1 REarth: • White Dwarf • A terrestrial planet White Dwarfs have a mass of ~ 1 Solar Mass, so the radial velocity amplitude should be ~ 100s km/s. This is excluded by low precision radial velocity measurements. „Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.” - Sherlock Holmes

34. CoRoT-7 is an active star with an RV jitter twice that the expected RV planet from the star RV (m/s) JD Prot = 23 d 44

35. CoRoT-7b sO–C = 1.7 m/s sRV= 1.8 m/s P = 0.85 d Mass = 7.3 MEarth A carefull analysis shows that you can extract the planet signal from the activity signal

36. 50

37. Tsurface ~ 1800 – 2600 C A lava ocean planet?

38. Art predicting reality? There is a popular German SF-series where a Lava planet - called Daa’mur– populated by exotic life forms which evolved from thermophile. Therefore its funny that the first transiting rocky planet (CoRoT-7b) fits in such a Lava-planet category.

39. The CoRoT-7 Planetary System CoRoT-7d CoRoT-7c P = 9 Days P = 3.7 Days Mass = 16.7 ME Mass = 12.4 ME The analysis of the radial velocity measurements reveals the presence of 2 additional planets. So why do these not transit?

40. CoRoT-7b,c,d 10o Only CoRoT-7b Transits

41. CoRoT-7b Kepler-10b 10 Iron enriched Earth-like 7 Earth Mercury r (gm/cm3) No iron 5 Venus Mars 4 3 Moon 2 From Diana Valencia 1 2 1.8 0.4 0.2 1 0.6 0.8 1.2 1.4 1.6 Radius (REarth)