1. Mass-loss from Evolved stars: High Spatial Resolution Studies Olivier Chesneau, Observatoire de la Côte d’Azur Collaborators (many…): Armando DomicianoBruno LopezSebastian Wolf Farrok Vakili Florentin MillourLuc DessartArnaud CollioudTijl Verhoelst Romain PetrovOrsola De MarcoMikako MatsuuraEric Lagadec Daniel BonneauAlbert ZijltraMichael MinChristain Hummel...

2. VLTI: short technical description VLTI+MIDI 37 optical elements (33 reflections) Until 200m baseline (and 350m of optical path!) Automatisation: Active optics (M1), chopping (M2), adaptive optics, moving delay lines, Variable curvature mirrors...

3. Preset

4. VINCI: K band test interferometer, No spectral dispersion, Strong point: measurement accuracy (1% and less), Main science objective: measurement of stellar radii Objects studied: Main sequence stars: Kervella, P., Thévenin, F., Ségransan, D., et al. 2003, A&A, 404, 1087 Kervella, P., Thévenin, F., Morel, P., Bordé, P., & Di Folco, E., 2003, A&A, 408, 681 Kervella, P., Thévenin, F., Morel, P., et al., 2004, A&A, 413, 251 Kervella, P., Thévenin, F., & Di Folco, E. 2004, A&A, 426, 297 Di Folco, E., Thévenin, F., Kervella, P., et al. 2004, A&A, 426, 601 F. Thévenin, P. Kervella, B. Pichon, P. Morel, E. Di Folco, & Y. Lebreton, 2005, accepté Cépheids: Kervella, P., Nardetto, N., Bersier, D., Mourard, D., et al., 2004, A&A, 416, 941, Kervella, P., Bersier, D., Mourard, D., et al. 2004, A&A, 428, 587 ET 2004, A&A, 423, 327 Kervella, P., Fouqué, P., Storm, J., et al. 2004, ApJ, 604, L113 Fast rotators: Domiciano de Souza, A., Kervella, P., Jankov, S., et al. 2003, A&A, 407, L47 Kervella & Domiciano de Souza, 2006 accepted Eta Car: van Boeckel, Kervella, Schöller et al., 2003, A&A, 410, L37

5. MIDI: N band interferometer (8-13 micron) Spectral dispersion, 30 et 230, accuracy 5-15%, 2 telescopes First interferometer of this kind (but see Keck), Main science goal: study of compact dusty objects Spectral types: any with dust… Young stars disk (all types), evolved stars (all types),… van Boekel, R.; Min, M.; Leinert, Ch. et al., 2004, Nature, 432, 479: Herbig AeBe stars Leinert, Ch.; van Boekel, R.; Waters, L.B.F.M.; Chesneau, O. et al., 2004, A&A, 423, 537 Chesneau, O.; Meilland, A.; Rivinius, T.; Stee, P. et al., 2005, : Be star Chesneau, O.; Verhoelst, T.; Lopez, B. et al., 2005, accepté, AGB, Chesneau, O.; Min, M.; Herbst, T.et al., 2005, accepté, Eta Carinae, supergiant Ohnaka, J.; Bergeat, T.; Driebe et al., 2005, A&A, 429, 1057 : AGB Ohnaka, J.; Driebe, T.; Hofmann, K. et al., 2006, A&A 445, 1015 : AGB Derroo, P.; Van Winckel, H.; Min, M. et al., 2006 astro.ph 1169: post-AGB Abraham, P.; Mosoni, L.; Henning, Th. et al. 2006 astro.ph 2334: FU Or object AGNs disks, Jaffe, W.; Meisenheimer, K.; Röttgering, H. J. A. et al., 2004, Nature, 429, 47, NGC1068 Poncelet, A.; Perrin, G.; Sol, H., 2006, A&A, accepted, astro.ph 12560, NGC1068 6 AGNS, 5 WR with dust, ~10 AGBs, 3 planetary nebulae, ~20 HaeBe, TTauri, massive young stars to come…

6. AMBER: J(1.2  m), H(1.6  m) and K (2.2  m) interferometer Strong points: spectral dispersion (1000,10000), 3 télescopes recombinaison, Multiple science goals: potential far from being explored Objects and phenomena studied: Main sequence: diameters, flattening and distortion, Young stars: disk-photosphere interface, cinematic, jets, material exchanges… Evolved stars: mass loss, molecular envelops, magnetism… AGNs : accretion disks, jets… Extrasolar planets : study limited to hot Jupiter ‘s, Several papers accepted or submitted: Wind-disk interface study of the Herbig AeBe MWC297 (Malbet et al., accepted) Dusty environment of the B[e] supergiant CPD-57 with MIDI et AMBER (Domiciano et al., accepted) Study of the truncated disk of the Be star, alpha Ara (Meillant, Stee et al., accepted), Study of the binary WR+O, gamma Velorum, (Petrov, Millour, Chesneau, et al., submitted)

7. 2003: 6 papers (VINCI) versus 17 for the year, MIDI commissioning 2004: 15 VLTI papers (12 VINCI, 3 MIDI) versus 27, Active concurrence! Keck interferometer (2 papers in 2004), IOTA, PTI, et NPOI, AMBER commissioning, 2005: 14 VLTI papers (9 VINCI, 5 MIDI), First CHARA papers (5), Keck interferometer (5), 30 papers published Information from: http://olbin.jpl.nasa.gov/ (Optical Long Baseline Interferometry News ) VLTI: science contribution

8. A complementary tool Adaptive Optics: NACO Some typical numbers:. L’ PSF FWHM: 100mas, strehl~60-75%, Dec: 50-60mas. K resolution: 60mas, Strehl~20-40%,. Dynamical range: 10 3 -10 4

9. Mass loss from evolved stars: loss of spherical sphericity I- Massive stars (‘Hot’) Lamers et Cassinelli, 1999 Associated issues:. Binarity,. Rotation,. X ray generation in radiative winds,. Supergiant eruptions and instabilities,. Supernovae Ib,c, II remanent geometry. Dust production from hot stars. LBVs,. B[e],. WR of carbon type,

10. The tip of the iceberg!

12. Smith et al., 2002, 2003

13. Understanding the visibilities with simple geometric models

14. Star flux and dust clumping N E N

16. The central star Question: what is the influence of the dust extinction on the inferred parameters of the model? Chesneau, O., Min, M., Herbst, T. et al., 2005

17. The B[e] phenomenon (Lamers et al. 1998) Zickgraf et al. (1985) Supergiants B[e]  L * /Lsun > 10 4 Observations point towards asymmetrical stellar environments Rotation? Binarity? Complex evolution? 

18. VLTI/MIDI spectrum and visibilities Gaussian models: 2a = (10.1  0.7) + (2.6  0.4) ( -8  m) mas Axial ratio 2b/2a = 0.76  0.11 Position angle PA = 145°  6° 2a = (15.3  0.7) + (0.45  0.22) ( -12  m) mas Axial ratio 2b/2a = 0.80  0.10 Position angle PA = 143°  6° B[e] supergiant star CPD-57° 2874 Domiciano de Souza, Driebe, Chesneau et al. 2006 A&A (astro-ph/0510735)

19. VLTI/AMBER spectrum and visibilities Gaussian models: 2a = (3.4  0.2) + (1.99  0.24) ( -2.2  m) mas Axial ratio 2b/2a = 0.53  0.03 Position angle PA = 173°  9° Br   2a = 4.5  0.3 mas ;  =1.8  0.2 10 -3  m

20. Measured sizes of CPD-57 2874

21. The close WR+O system: gamma 2 Vel P=78 days,spectroscopic parameters well constrained WR almost as bright as the O star in K No dust!

23. Can we resolve the WR star? Not with baselines smaller than 100m in K band, Better in H and very good in J (He10830) We therefore expect a ‘simple’ binary signal

24. O8III+WC8 star Teff WC8 ~60000K Teff O8III ~30000K  flux cont =0.62  flux Int =0.75

25. Distance to be revised? Hipparcos: 258 +41 -31 AMBER: 367 +42 -37 Petrov, R., Millour, F., Chesneau, O., et al., 2006, submitted To come: study of the wind-wind collision (with more data…) confirmation of distance (with much smaller error bars)

26. Mass loss from evolved stars: loss of spherical sphericity II- Evolved ‘small’ stars (‘cool’) Associated issues:. Binarity, symbiotic systems,. Planetary nebulae geometry,. Galactic dust production,. Novae, supernovae Ia …

27. Massive AGB long pulsator OH26.5+0.6 MIDI ISO P=1559 days Embedded object: m J =17, m K =8, m N =-3!

29. Chesneau, O., Verhoelst, T., Lopez, B., et al., 2005 Complex objects:. Many opacities ignored:. Dusty opacities,. Molecular opacities,. Non-spherical geometry (always?),. Slow temporal variability, About 140h of Ats observations planned on OH/IR embedded sources! (PI: Driebe and Verhoelst)

30. CPD-56°8032 and Hen2-113 Central Stars [ De Marco et al. 97 ] –Late Wolf-Rayet [WC10] –Teff ~ 30000 K –L ~ 5000 L o, dM/dt=8-40 10 -7 M o /yr –Wind: 160- 225 km.s -1 Nebula [ Waters et al. 98, Cohen et al. 02, De Marco et al. 02 ] –Strong IR emission  dust –Edge-on disk suspected for CPD-56°8032 (STIS/HST) –Strong PAH emission, together with crystalline silicates features –Double chemistry : C (central star, ‘hot’ disk) and O (‘cold’ disk ?) –Distance: ~1.5 kpc Col: A. Collioud (OCA,Fr), E. Lagadec (OCA, Fr), O. De Marco (AMNH, USA), A. Zijlstra (UMIST, UK), S. Wolf (MPIA, Ger), A. Acker (Obs Strasb., Fr), G. Clayton (LSU,USA), B. Lopez (OCA,Fr)

31. HST NACO MIDI

32. HST NACO Lagadec, E., Chesneau, O., Matsuura, M et al., 2006 L’M’ Central source magnitude in L’ and M’ respectively 300 and 800 more luminous than any [WR] models! Central object resolved by NACO! FWHM~155mas

33. CPD-56 dusty core: a compact source 8.7  m deconvolved image (30% PAHs)

34. MIDI data on CPD-56°8032CPD1 B=45.7 m PA = -5° CPD2 B=45.6 m PA = 5° CPD3 B=41.2 m PA = 51° CPD1 CPD2 CPD3 N Résolution 36 mas à 8 µm 60 mas à 13.5 µm

35. Best geometrical model for CPD-56°8032 ? N -15 +/- 5° R = 72 +/- 3 mas (110 +/- 5 UA) i = 29 +/- 5° E CPD1 B=45.7 m PA = -5° CPD2 B=45.6 m PA = 5° CPD3 B=41.2 m PA = 51° Good model ???

36. Towards complex models MC3D Parameters Density (2d disk) with α = 2.0 β = 1.5 h o = 0.01 R * [ Shakura & Sunyaev 1973 ; Wood et al. 2002, Wolf 2005 ] 2000 AU 500AU α = 2.0 β = 1.5 h(100 UA)=10 UA

37. 10 micron image Résolution : 13 mas par pixel Best model SED fit based on carbon chemistry only

38. High-Resolution view of CPD-568032 10  m image 8.7  m image (30% PAHs) Chesneau, O., Collioud, A., de Marco, O., et al., 2006, submitted

39. The connection between PNs/SNIa and symbiotic systems: recurrent novae RS Oph is in outburst since the 13 th of Feb. 2006 Last outburst: January 1985! Estimated distance: 600pc (1.5-2.3kpc…) DDT proposal (O. Chesneau, C. Hummel, F. Millour, M. Vannier): AMBER data taken the 18 th of Feb.

40. First data Typical sizes: continuum 3.5-4.5mas, Br  6.5-9 mas (overresolved) Dynamics in Br  complex… Object centro-symmetric in continuum (fireball)

41. Other objects: QX Pup (OH231.8+4.2) Matsuura, M, Chesneau, O., Zijlstra, A et al., 2006, in preparation HST optical HST Nicmos NACO 2.12 NACO L’ band

42. MIDI spectrum MIDI correlated flux Typical extensions: (Gaussian model)

43. Actual situation:. Papers are based on 2-6 visibility measurements only,. UT time pressure,. ATs commissioning in progress,. Limiting magnitude problems (no fringe tracker…). Interesting science only with a coupling with classical techniques (polarimetry, spectroscopy, radio imaging…). The progress will be slow:. The VLTI is now almost crystallized,. We have to ‘learn and understand’ the VLTI. Give access to broad community, Success: Only interferometer worldwide offered in Open Time!. Pionnier in extragalactic studies, mid-IR regime and high spectral resolution,