2. 1Tsevi Mazeh: Leuven-Binaries

3. 2

4. 3 Double stars Rev. John Mitchell - 1767 it is highly probable in particular, and next to a certainty in general, that such double stars as appear to consist of two or more stars placed very near together, do really consist of stars placed near together, and under the influence of some general law. The definitive existence of binary stars was demonstrated by William Herschel in 1802. Tsevi Mazeh: Leuven-Binaries

5. 4 A multitude of types Binary stars astrometriceclipsing spectroscopic Visual Resolved by telescope into two stars Oscillatory motion on the sky Stars periodically pass in front of each other in our LOS Unresolved by telescope, but two sets of spectral lines seen Tsevi Mazeh: Leuven-Binaries

6. 5 Example of Visual Binaries Krueger 60 : d = 4 pc M3.5V + M 4V, Period = 44.5 years

7. 6 Example of Visual Binaries Tsevi Mazeh: Leuven-Binaries

8. 7 a d

9. 8 Keplers 3rd law:

10. 9 Ursa Major, The Big Bear (Big Dipper) Mizar was the first known binary, noticed in 1650 by Riccioli. Tsevi Mazeh: Leuven-Binaries

11. 10 Mizar: A binary within a binary Tsevi Mazeh: Leuven-Binaries

12. 11 Resolution of a telescope Tsevi Mazeh: Leuven-Binaries

13. 12 Binary system Mizar A Observed by NPOI Navy Prototype Optical Interferometer (NPOI) Array south of Flagstaff AZ, The Mizar images were obtained with the inner three 0.5m telescopes. A total of 10 telescopes will be operational starting in 2003. Mizar A binary (period 20 days). 0.01 arcsec Tsevi Mazeh: Leuven-Binaries

14. 13Tsevi Mazeh: Leuven-Binaries

15. 14 Example: Wavelength λ=500nm, baseline B=100m Θ ~ 0.001 = 1 mas CHARA – Center for High Angular Resolution Astronomy at Georgia State University SUSI – Sydney University Stellar Interferometer NPOI - Navy Prototype Optical Interferometer Mark III Interferometer PTI - Palomar Testbed Interferometer Tsevi Mazeh: Leuven-Binaries

16. 15Tsevi Mazeh: Leuven-Binaries

17. 16Tsevi Mazeh: Leuven-Binaries

18. 17Tsevi Mazeh: Leuven-Binaries

19. 18 Keck Interferometer (2x10m) Mauna Kea, Hawaii VLT Interferometer (4x8m) Chile (ESA) Examples of Optical Interferometers Tsevi Mazeh: Leuven-Binaries

20. 19 a1a1 a2a2 M1M1 M2M2 CM Tsevi Mazeh: Leuven-Binaries The binary motion

21. 20Tsevi Mazeh: Leuven-Binaries

22. 21Tsevi Mazeh: Leuven-Binaries

23. 22Tsevi Mazeh: Leuven-Binaries

24. 23 Planet Tsevi Mazeh: Leuven-Binaries

25. 24 Kepler first law:

26. Tsevi Mazeh: Leuven-Binaries25 Kepler second law:

27. 26 Origin of orbits of both stars Periastron point Empty Tsevi Mazeh: Leuven-Binaries

28. 27 The Masses of Sirius A & B –5 th closest star to us: d = 2.63pc –Sirius A is the brightest star in the sky Tsevi Mazeh: Leuven-Binaries

29. 28 Wobble of Sirius Tsevi Mazeh: Leuven-Binaries

30. 29 Sirius AB Binary System HST image

31. 30 Orbits of Sirius A and B Tsevi Mazeh: Leuven-Binaries

32. 31 Sirius AB Binary System Tsevi Mazeh: Leuven-Binaries

33. 32 Ratio of motion: Distance estimate: a = 7.62 20.04 AU at a distance of 2.63 pc M 1 + M 2 = (20.04) 3 /(49.9) 2 = 3.23 Keplers 3rd law: Tsevi Mazeh: Leuven-Binaries Sirius AB Binary System

34. 33 Hence M 1 / M 2 = 2.3 and M 1 + M 2 = 3.23 –so, unraveling the masses gives M 1 = mass of Sirius A = 2.25 M M 2 = mass of Sirius B = 0.98 M Tsevi Mazeh: Leuven-Binaries Sirius AB Binary System

35. Tsevi Mazeh: Leuven-Binaries34 1915-Adams obtained a spectrum of Sirius B T~25,000 K 1862- Clark resolved the two stars Sirius AB Binary System

36. 35 The H-R Diagram Tsevi Mazeh: Leuven-Binaries L = 4 R 2 T 4

37. 36 The Sizes of Stars Tsevi Mazeh: Leuven-Binaries

38. 37 Gliese 229B 8 separation 10 mag difference in J,H,K (Nakajima 1995) Tsevi Mazeh: Leuven-Binaries

39. 38 A multitude of types Binary stars astrometriceclipsing spectroscopic Visual Resolved by telescope into two stars Oscillatory motion on the sky Stars periodically pass in front of each other in our LOS Unresolved by telescope, but two sets of spectral lines seen Tsevi Mazeh: Leuven-Binaries

40. 39Tsevi Mazeh: Leuven-Binaries

41. 40 One star with a spectrum composed of two spectra Tsevi Mazeh: Leuven-Binaries

42. 41 The Doppler Effect Spectrum of Hydrogen in Lab Spectrum of a Star Tsevi Mazeh: Leuven-Binaries

43. 42 Spectroscopic binary Spectrum of Hydrogen in Lab Spectrum a Star…..Day 1 Spectrum a Star…..Day 2 Spectrum a Star…..Day 3 Spectrum a Star…..Day 4 Tsevi Mazeh: Leuven-Binaries

44. 43 To earth Tsevi Mazeh: Leuven-Binaries

45. 44 Spectroscopic Binaries If the Doppler shift of a stars absorption lines changes with time (redshift, then blueshift, then redshift, etc.), its a spectroscopic binary. Tsevi Mazeh: Leuven-Binaries

46. 45 Spectroscopic Binaries Double-lined spectroscopic binary. Tsevi Mazeh: Leuven-Binaries

47. 46 Spectroscopic Binaries Tsevi Mazeh: Leuven-Binaries

48. 47 Single-lined spectroscopic binary (SB1)

49. Tsevi Mazeh: Leuven-Binaries48 Single-lined spectroscopic binary (SB1)

50. 49Tsevi Mazeh: Leuven-Binaries

51. 50 Eclipsing Binaries Animation Tsevi Mazeh: Leuven-Binaries

52. 51 Time T 1 = first contact Time T 2 = beginning of total eclipse Time T 3 = end of total eclipse phase Time T 4 = last contact Time Brightness T1T1 T2T2 T3T3 T4T4 Tsevi Mazeh: Leuven-Binaries

53. 52 Star of radius R 1 Star of radius R 2 a Orbit of star 2 relative to star 1 Eclipse zone T1T1 T2T2 T3T3 T4T4 LOS Tsevi Mazeh: Leuven-Binaries

54. 53Tsevi Mazeh: Leuven-Binaries

55. 54 The geometry of the eclipse Tsevi Mazeh: Leuven-Binaries

56. 55 Relative dimension: Relative surface flux Inclination

57. 56 CoRoT-Exo-2 Tsevi Mazeh: Leuven-Binaries

58. 57Tsevi Mazeh: Leuven-Binaries

59. 58 Absolute Properties of the Main-Sequence Eclipsing Binary Star BP Vulpeculae Tsevi Mazeh: Leuven-Binaries Lacy et al. 2003

60. 59 BP VULPECULAE Tsevi Mazeh: Leuven-Binaries

61. 60 BP VULPECULAE

62. Tsevi Mazeh: Leuven-Binaries61 BP VULPECULAE

63. Tsevi Mazeh: Leuven-Binaries62 BP VULPECULAE

64. Tsevi Mazeh: Leuven-Binaries63

65. Tsevi Mazeh: Leuven-Binaries64