"Learning the (other) worlds" Valentin D. Ivanov

Transcription

1 "Learning the (other) worlds" Valentin D. Ivanov The exoplanet studies were born at the border of two fields - binary star and the Solar system studies. I will review the history of the exoplanet research, the latest results, and will summarize the most important questions that have remained unanswered.

2 What is an exoplanet? Exoplanet = planet around another star! IAU definition (2006) of a planet: (1) planets are rounded by their own gravity (2) no termonuclear fusion (<=13: Jupiter masses) (3) wiped out the neighbouring planetesimals Plot by Michael Richmond, RIT I know when I see it!

3 What is an exoplanet? Disclaimer: dwarf planets Disclaimer: free-floating planets (planemo): Zapatero Osorio et al. 2000, Sci, 290, 103; Jayawardhana & Ivanov, 2006, Sci, 313, 1279; Luhman 2013, ApJ, 786, L18

4 Planet formation Limiting sensitivity of techniques of planet finding.

5 The Challenge - planets are much lighter than their host stars: Sun : Jupiter : Earth = : 320 : 1; Vrad amplitudes m/s (Pasquini 2009; Dumusque et al. 2012, Nat, 491, 207)

6 The Challenge - planets are much fainter than their host stars: Beta Pic b L = mag (Lagrange et al. 2009, A&A, 493, L21)

7 The Challenge - planets are much fainter than their host stars: Beta Pic b L = mag (Lagrange et al. 2009, A&A, 493, L21)

8 Search methods Perryman (2012)

9 Early discoveries of exoplanets 1952, Obs, 72, 199:

10 Early discoveries of exoplanets 1952, Obs, 72, 199:

11 Search methods The filled circles indicate the planets found by radial velocity surveys (blue), transit surveys (red), and microlensing surveys (yellow). Also indicated by the filled circles are pulsar planets (violet) and the companion to a young brown dwarf (dark red). The astrometric and radial velocity limits are from equations given by Perryman (2000); the microlensing limit is from Bennett (2006); the transit survey limits are the editors approximations from available data (as of 2006). Planets in our Solar System are also indicated. Reproduced from Earth-Like Exoplanets:The Science of NASA s Navigator Program, Eds. Lawson & Traub, 2006, JPL Publ.

12 Search methods Batalha (2014)

13 Astrometry Note: it can be done in radio (long base lines!), e.g. planet search aorund the M8.5 Dwarf TVLM (Forbrich et al. 2013)

14 Astrometry - prehistoric claims - see the review by Perryman 2012, AsBio, 12, 928: ASTROMETRY: - Mp = 10 Mj, P=17 yrs in 70 Oph Jakob (1855), See ( ), Reuyl & Holmberg (1943) - Mp = 16 Mj, P=4.9 yrs in 61 Cyg Strand (1943) Both planets killed by Heintz (1978). Barnard star 0.5 ND 0.7 Mj, van de Kamp (1962) VB 10 b Pravdo and Shaklan (2009) Luh 16 AB b Boffin et al. (2014)

15 Astrometry - HD b: 1.5 (+/-0.3) Mj, P= (+/-40.0) d (Muterspaugh et al. 2010, AJ, 140, 1657) - Palomar Testbed Interferometer (PTI):

16 Astrometry - Gaia - Gaia astrometric accuracy: 10/20-25/300 micro-arcsecs for V=7-12/15/20 mag - Perryman (2014): (+/-6000) jupiters (1-15 Mj) at D<500pc for 5yr moission; exoplanets around M dwarfs at D<100 pc

17 Radial Velocity

18 Radial Velocity - prehistoric claims RADIAL VELOCITY: 1.7 Mj, P=2.7 yrs gamma Cep A b: - discovered by Campbell et al. (1988) - retracted by Walker et al. (1992) - confirmed by Hatzes et al. (2003)

19 Radial Velocity - prehistoric claims RADIAL VELOCITY: 1.7 Mj, P=2.7 yrs gamma Cep A b: - discovered by Campbell et al. (1988) - retracted by Walker et al. (1992) - confirmed by Hatzes et al. (2003)

20 Radial Velocity - prehistoric claims RADIAL VELOCITY, other claims: - 11 Mj, P=84 d - HD b Latham et al. (1989), confirmed by Cochran et al. (1991) and Butler et al. (2006) - PSR B Wolszczan & Frail (1992) Mj, P=558 d HD b - Hatzes and Cochran, (1993), confirmed by Hatzes et al. (2006) Mj, P=4.2 d (a=0.05 AU) 51 Peg b Mayor & Queloz (1995)

21 Pulsar planets Method: measure the relative time delay between pulsar pulces - 2 M_earth, P=16.9 yr PSR B Demianski and Proszynski (1979) - 10 M_earth, PS R b 1991, Bayles, Lyne & Shemar 1991, Nat, 352, 311; later retracted and 3.4 M_earth, P=98.2, and 66.6 d, PSR b and c, Wolszczan & Frail 1992, Nat, 355, PSR B (Backer et al. 1993; Thorsett et al. 1993)

22 Microlensing - originally a dark matter search in MW bulge and LMC/SMC fields - Mao & Paczynski (1991 ApJ, 374, L37), Gould & Loeb 1992, ApJ, 396, 104) posisbility to study binarity and planetary systems - exoplanet.eu : 6 confirmed mirolensing planets

23 Microlensing planets First detectoin: 2.6(+0.8/-0.6) M_Jup - Bond et al. 2004, ApJ, 606, L155

24 Microlensing planets Microlensing parallax Yee et al. 2015, ApJ, 802, 76

25 Direct imaging The first directly imaged planet 2M1207b: L5-L9.5, Teff~1250+/-200 K, 5+/-2 M_Jup (Chauvin et al. 2004, A&A, 425, L29); primary 25 M_Jup; D~53 pc,

26 Direct imaging This was made possible because of the infrared wavefront sensor!

27 Direct imaging ADI = angular differential imaging; SDI spectral differential imaging

28 Direct imaging Speckle noise attenuation process achieved by ADI. Panel (a) shows a typical image after subtraction of an azimuthally symmetric median intensity profile; panels (b) and (c) both show, with a different intensity scale, the same image after ADI subtraction; and panel (d) shows the combination of 117 such speckle-subtracted images. The faint point source visible in panel (d) at (2.43", 7.3º) is 1 million times fainter than the star. (Gemini Observatory)

29 Direct imaging Marois et al. (2008, Sci, 322, 1348; 2010, Nat, 468, 1080): bcde 7/10/10/9 Mj, Spectra: Janson et al. (2010), Oppenheimer et al. (2013), Zurlo et al. (2016) Exoplanets.eu: 88 planets / 81 planetary systems / 5 multiple planet systems

30 Direct imaging diurinl rotation CO bandhead rotational broadening: Snellen et al. (2014, Nat, 509, 63), Schwarz et al. (2016, A&A, 593, 74), Allers et al. (2016, ApJ, 819, 133) Rotational modulation by spots: Zhou et al. (2016, ApJ, 818, 176)

31 Wavelength calibraiton ThAr lines (Seemann et al. 2014)

32 Gas Cells - hydrogen fluoride (HF; poisoneous and corrosive!) Campbell & Walker (1979) - iodine (I2) Beckers (1976), Koch & Woehl (1984), Marcy & Butler (1992) - methane CH4, amonia NH3, acethylene C2H2 for the infrared Seemann et al. (2014) 3-5 m/s accuracy

33 Gas Cells - Infrared Seifahrt et al. (2010, A&A 524, 11), Seifahrt & Kaufl (2008, A&A 491, 929), Figueira et al. (2010, A&A, 515, 106): telluric lines yield stability of ~10-30 m/s The destroyer of worlds... - Huelamo et al. 2008, A&A, 489, L9), Bean et al. (2010, ApJ, 711, L19)

34 Resources Catalogs exoplanets.eu; 3672 planets / 2752 planetary systems / 616 multiple planet systems Database confirmend planets, 4496 Kepler candidates, 586 multiplanet systems Community analisys and tools: - The Exoplanet Exploration Program Analysis Group (ExoPAG) ETD - Exoplanet Transit Database: Extrasolar Planet Transit Finder: sits K2 photometry, detrended by Andrew Vandenburg, at MAST: The Exoplanet Handbook, by Michael Perryman: %2012/Miscellaneous/Projects/Habitability/Perryman,%20Michael%20-%20The %20Exoplanet%20Handbook.pdf