VEGA/CHARA: Status and First Science SPIE 2010 San Diego

1. VEGA/CHARA: Status and First ScienceSPIE 2010 San Diego M. Tallon, D. Mourard The VEGA and CHARA Teams

2. Differential measurements Fundamental parameters Mode 3T HD3360- 10-08 High Angular (0.3mas) and up to 30000 spectral resolution Old GI2T Facility CHARA Array 09-2007: Integration 07-2008: First observations 07-2009: Remote operation 06-2010: First science papers VEGA SPIE San Diego

3. Instrumental visibility Spectrograph Characteristics Limiting magnitude Differential phase Polarisation behaviour Summary of performances (Mourard et al, A&A 508 2009) sV²Cal≈2% R0=8cm R0=15cm s(j)≈1-2° VEGA SPIE San Diego

4. Recent advances Routine remote operations thanks to the CHARA staff Blind recording with IR tracking (CLIMB, new IR CHARA instrument) Simultaneous observations between visible VEGA and IR FLUOR End of night automated pipeline for quality check Off line data analysis compatible with the OI-FITS norm. Standard use of the JMMC web-service like LITPro (model fitting) VEGA SPIE San Diego

5. Summary of the VEGA Science Programs • First science papers • AB Aur: Perraut et al, A&A 516, L1 (2010) • A/B Supergiants: Chesneau et al, A&A in press (2010) • Circumstellar environments • Kinematics study in the circumstellar environment of Be stars (Delaa et al.) • Interactive massive stars: ups Sgr (Chesneau et al.) and bet Lyr (Bonneau et al.) • Fundamental parameters • 13 Cyg(exoplanet host star) • bet Cep (extended environnement and companion) • roAp stars (angular diameter and Teff) • sub giants radii and orbits (class IV stars) • But also: epsAur (famous eclipsing system), alp Cep (rotation), P Cyg (stellar wind), theta OriC (Ha line forming region)… VEGA SPIE San Diego

6. Fukagawa, 2004. Subaru AB Aur is a prototype of Herbig Ae/Be stars and, as such, it has been fully observed in spectroscopy, in infrared interferometry (PTI, IOTA, …) • Spectral type : A0 • Magnitudes : V = 7.1 / K = 4.4 • Distance : 144 pc • Luminosity : 47 L • Large infrared excess • No jets, no CO flow • Variability of the Ha emission at a scale of a few hours  Stellar activity, link wind and disc, … VEGA SPIE San Diego

7. VEGA observations Ha V² 1 • 2008. S1S2: Clear spatial resolution of AB Aur in Ha • 2008. W1W2: Fringes but SNR too poor • 2009. S1S2: Tracking problem l Wind modelling PCygni profile

8. Interpretation Additional component X-Wind D-Wind

9. Interpretation • A wind only does not allow us to reproduce the spectrum AND the visibility curve, even if this wind is very extended.  Another component has to be considered. We assume a brightness assymetry in agreement with : - the spiral arms detected at few hundreds of AU - the non-null closure phase measured by Millan-Gabet et al. (2006) - the binarity signals recorded by spectro-astrometry by Baines et al. (2006)  7% of flux @ ~40mas (5.5 AU) Perspectives: - Observe AB Aur in 2010 with larger baselines to resolve its photosphere - Take benefit of IR fringe tracking

10. Deneb, Przybilla et al. 2008 Rigel, Kaufer et al. 1997, PhD thesis • Interests in the visible of A/B supergiants (e.g. Deneb A2Ia, and Rigel B8Ia): • - Very bright and used as stellar candles, • large diameters (60-100 solar radii), Deneb and Rigel are 2-3mas sources • Variability in Ha line (R>10000), sensitive to mass-loss and its perturbation, time scale weeks to months. VEGA SPIE San Diego

11. VEGA/CHARA observations of Deneb: the Ha line Time variability I f Spatial variability l I V f VEGA SPIE San Diego

12. Full 1D modeling of the wind of Deneb Synthetic spectra for different mass-loss rates I I V l l • Parameters from the model of Schiller et al. 2008 • Conclusions: • The Ha line is complex with subtle opacity effects, • The visibility curve is a sensitive indicator of mass-loss rate. The current modeling succeeds in fitting the data by changing the mass-loss rate. • The differential phase signals clearly indicates asymmetries in the wind, changing with time. Progresses in the modeling are necessary. VEGA SPIE San Diego

13. FundamentalstellarparametersWorks in progress • Angular diameters: • 13 Cyg : F4V (Exoplanets) • gEqu : A9p (roAp) • Mass • β Cep : B2IIIev (pulsating binary) • 48 And : F5IVe(sub-giants) • Rotation • α Cep : A7IV(fast rotator) • Be stars envelopes VEGA/CHARA high angular resolution allows the study of main sequence stars VEGA SPIE San Diego

14. Measurements of angular diameters 1% 2% 4000 stars brighter than mV=6.5 that can be detected by VEGA with accuracy better than 2% constraints on models (Creevey et al. 2007, Kervella et al. 2008) VEGA SPIE San Diego

15. Visible 3T observations and infrared FT mK<4.5 mK<5.0 VEGA SPIE San Diego

16. Conclusions • VEGA/CHARA is now operational in routine and remote in 2T mode: • medium and high spectral resolution for circumstellar at atmosphere/chromosphere studies • Medium and low spectral resolution for fundamental stellar parameters • Mourard et al. A&A 2009, Perraut et al. A&A 2010, Chesneau et al. A&A 2010 (accepted) • Development of the 3T mode  external fringe tracker. • Publications submitted or in preparation: • Nardetto et al. A&A (environnement of beta Cephei) • Delaa et al. A&A (kinematics of Be stars) • Chesneau et al. A&A (environnement of ups Sgr) • Bonneau et al. A&A (environnement of beta Lyrae) • Perraut et al. A&A (ro Ap diameter and Teff determination) • Bério et al. A&A (chromospheres of K giant stars) • Mourard et al. (Ha in e Aur) • Mourard et al. (characterization of exoplanets host stars) Thanks a lot to CHARA and VEGA colleagues! More detailed informations on http://www-g.oca.eu/gemini/projets/vega/en/present/ VEGA SPIE San Diego