1. Binary systems: from 0.2 arcsec to 2 deg Double stars observers 2010 José Antonio Caballero Centro de Astrobiología (CSIC-INTA), Madrid

2. Caballero 2006, PhD Formation, evolution and multiplicity of brown dwarfs and giant exoplanets Planets in close orbits: search for transits ( photometric variability) Planets in wide orbits: deep wide imaging No planets with CAIN-II/1.5m TCS… An example, a stable, single brown dwarf: Kelu 1

3. Caballero 2006, PhD Substellar objects De fuscis pusillis astris et giganteis exoplanetis Object 2 H burning 1 H burning Mass (M sol [M Jup ]) (Z sol ) star yes >0.075 [> 72] Sub- stellar object Brown dwarf yesno 0.075- 0.013 [72-14] Planet no <0.013 [< 14]

4. Caballero 2006, PhD Search for very low-mass objects surrounding nearby young stars Direct imaging with near-infrared adaptive optics systems at 4 m- class telescopes: Naomi+Ingrid / 4.2 m WHT Alfa+Omega-Cass / 3.5 m Calar Alto AdOpt-at-TNG / 3.6 m Telescopio Nazionale Galileo And coronography with: NICMOS / Hubble Space Telescope

5. Caballero 2006, PhD Search for very low-mass objects surrounding nearby young stars Complement: wide-field search with CAIN-II / TCS and other instruments Able to detect all brown dwarfs at s > 50 AU and all planets with M > 0.008 M sol at s > 100 AU... Example: G 196-3A and B, a young star in the Local Association with an L-type companion of… 0.020-0.030 M sol

6. Caballero 2006, PhD HD 189087 AB : from 7 x 7 arcmin 2 to 3 x 3 arcsec 2

7. Caballero 2006, PhD Search for very low-mass objects surrounding nearby young stars 51 systems with features of youth (lithium, chromospheric activity, X-ray emission, membership in moving groups): - 44 with ages 600 Ma - 32 with ages 100 Ma * 3-4 new stellar companions * Upper limits on the frequency of companions * BUT... AB Dor C HD 160934 AC HN Peg B

8. Caballero 2006, PhD Search for very low-mass objects surrounding nearby young stars 51 systems with features of youth (lithium, chromospheric activity, X-ray emission, membership in moving groups): - 44 with ages 600 Ma - 32 with ages 100 Ma * 3-4 new stellar companions * Upper limits on the frequency of companions * BUT... AB Dor C HD 160934 AC HN Peg B

9. Caballero+ De Mayrit al cielo: Orionis cluster ( ~ 3 Ma, d ~ 385 pc) The most complete initial mass function (from 18 to 0.003 M sol ) Brown dwarfs (with discs, X-ray emission, H emission…) and isolated planetary- mass objects

10. Caballero 2009, CoolStars15 De Mayrit al cielo: Orionis cluster ( ~ 3 Ma, d ~ 385 pc) Very wide binaries + Statistical approach 3 resolved systems with probabilities of alignement by chance of 1% (2 are triple) Separations: 7.6-14.1 arcsec (2700-5100 AU) And…

11. Caballero et al. 2006, A&A De Mayrit al cielo: Orionis cluster ( ~ 3 Ma, d ~ 385 pc) B: S Ori 68: L5.0, ~5 M Jup, H A: [SE2004] 70: M6.0, ~45 M Jup, low-gravity, X- ray flare, H, radial velocity, Li I = 4.6 arcsec s =1700 AU The widest planetary system?

12. Caballero+ De Mayrit al cielo: Orionis cluster ( ~ 3 Ma, d ~ 385 pc) Important because: it illuminates the Horsehead Nebula X-ray emitter population discs at 3 Ma a helium-rich, magnetically-active B2Vp star Herbig-Haro objects accretion rates and frequency…

13. Caballero 2006, PhD Ori (Uranometria: Bayer 1603) 48 Ori (Flamsteeds catalogue: Flamsteed 1712) BD-02 1326 (Bonner Durchmusterung des sudlichen Himmels: Schonfeld 1886) HD 37468 (Henry Draper catalogue: Cannon & Pickering 1925)

14. Caballero 2007, AN Ori E (Tabula Nova Stellarum Duplicium: Mayer 1779) Ori C, D (Struve et al. 1876) Ori B (Burnham 1892)

15. Caballero 2005, AN 10 000 AU A near-IR counterpart of a mid-IR source: Ori IRS1, an evaporating proplyd? Also detected in X- rays (Caballero et al. 2010, A&A)

16. Caballero in prep. Ori B Ori IRS1 Ori A On-going high- resolution (lucky) imaging (with FastCam/1.5 m TCS) A*: O9.5V, 18 M sol B: B0.5V, 12 M sol C: A2.0V, 2.7 M sol D: B2.0V, 6.8 M sol E: B2.0Vp, 7.4 M sol

17. Caballero in prep. Angular separation of ~ 0.26 arcsec (with FastCam/2.5 m NOT)

18. Un- published Angular separation of ~ 0.26 arcsec (with FastCam/2.5 m NOT) And NaCo/8.4 m VLT resolves Ori IRS1!

19. Caballero in prep. Orionis: The most massive binary with an astrometric orbit (Mason et al.)

20. Caballero in prep. Orionis: The most massive binary with an astrometric orbit (Mason et al.) New fit: a = 0.264 0.006 arcsec e = 0.0528 0.013 i = 154.9 1.0 deg P = 155.4 0.5 a

21. Simón-Díaz & Caballero in prep. On-going high-resolution spectroscopy (P~143 d; Aa: O9.5V, 18 M sol, Ab: B0V, 15 M sol ) T Aa = 34 kK, vsini = 110km/s T Ab = 32 kK, vsini = 30km/s T B = 31 kK, vsini = 60km/s Up to 18+15+12 = 45 M sol !

22. Caballero 2008, A&A

23. Caballero et al. 2007, A&A The mass function down to the planetary domain in the Orionis cluster Derivation of the mass function from 0.11 to 0.006 M sol, with index = 0.4-0.6 ( N/ M M - ; Salpeter: = 2.35). Frequency of Orionis brown dwarfs with discs is 47 ± 9 %

24. Caballero et al. 2007, A&A The mass function down to the planetary domain in the Orionis cluster Derivation of the mass function from 0.11 to 0.006 M sol, with index = 0.4-0.6 ( N/ M M - ; Salpeter: = 2.35). Frequency of Orionis brown dwarfs with discs is 47 ± 9 %

25. Caballero 2007a, A&A

26. Koenigstuhl 1AB : a serendipitous discovery… A: LEHPM 494 [?] B: DENIS J0021.0-4244 [M9.5V] ~ 1.3 arcmin B UK Schmidt 1977.6 R ESO 1984.9 IJK DENIS 1996.5 R UK Schmidt 1996.6 I UK Schmidt 1999.6 JHKs 2MASS 1999.6 [3.8:8.0] Spitzer 2004.0

27. Caballero 2007a, A&A Koenigstuhl 1AB : the (second) widest ultracool binary: a challenge for very low-mass formation ejection scenarios! = 77.76 ± 0.07 arcsec d = 23 ± 2 pc s = 1800 ± 170 AU M A = 0.103 ± 0.006 M sol M B = 0.079 ± 0.004 M sol Highlight of the week in A&A. Almost cover page!

28. Caballero 2007b, ApJ Koenigstuhl 2 AB: A new very low-mass star in a wide binary (the third widest system with M A + M B < 0.4 M sol ) Primary: LP 655-23 (Luyten 1979) Secondary: 2M0430-08 (M8.0V; Cruz et al. 2003) s = 450 ± 40 AU M A = 0.26 ± 0.04 M sol M B = 0.086 ± 0.004 M sol

29. Caballero 2007b, ApJ Koenigstuhl 3 ABC: the widest system containing an L dwarf component Primary: HD 221356 (F8.0V; Hipparcos) Secondary: 2M2331-04AB (M8.0V+L3.0V; Gizis et al. 2000, 2003) = 7.530 ± 0.007 arcmin s = 11900 ± 300 AU M A = 1.02 ± 0.07 M sol M BC = 0.088+0.072 M sol

30. Caballero, Miret et al. in prep A Virtual Observatory search for companions to Luyten stars 20 physical systems with both star components in Hipparcos 29 physical systems with only one star component in Hipparcos 19 physical systems with no components in Hipparcos Half a dozen new serendipitously-discovered physical systems

31. Caballero et al. 2010, A&A G 125-15 AB + G 125-14 = WDS 19312+3607 (see paper in folder)

32. Caballero et al. 2010, A&A

33. Caballero 2009, A&A Reaching the boundary between stellar kinematic groups and very wide binaries. I WDS stars with the widest angular separations ( > 999 arcsec): N=30 Visual or unidentified doubles: N=23 Physical double candidates: N=7 (including Centauri A, B and C)

34. Caballero 2009, A&A Reaching the boundary between stellar kinematic groups and very wide binaries. I Six stars with s > 0.1 pc (previously assumedupper limit to the distribution of wide binary semimajor axes) Four stars with s > 0.2 pc Comparison of gravitational binding energies (U=-GM A M B /r)

35. Caballero 2009, A&A

36. Caballero 2010, A&A Reaching the boundary between stellar kinematic groups and very wide binaries. II The widest binary!

37. Caballero 2007a, A&A

38. Caballero & ??? Future: Luyten stars (& Miret et al.) nearby young stars (& Alonso-Floriano, Montes) ultracool dwarfs (& Montes) and much, much more…