Corot Week 6 1

Targets selection

Be stars

Paris-Meudon Observatory: A.-M. Hubert, M. Floquet, C. Neiner

Univ. of Valencia: J. Fabregat, J. Gutierrez-Soto, J. Suso

Univ. of Sao Paulo: E. Janot-Pacheco, L. Andrade, S. Daflon

Royal Observatory of Belgium: Y. Frémat

ESA, Estec, RSSD: C. Neiner

Corot Week 6 2

Early and late Be stars: 2 science goals

Early Be stars (B0-B3): pulsations and multiperiodicity already detected from the ground

Is the beating effect of close pulsation periods the cause of the Be phenomenon i.e. the presence of a disk around Be stars?

Effects of fast rotation and magnetic field on the pulsations

Late Be stars (B4-B9): pulsations predicted by theory but the amplitude is too small to be detected from the ground

detection of pulsations with Corot!

Corot Week 6 3

Photometric variability: Hipparcos(Hubert & Floquet )

Some of the targets observed by Hipparcos: periodicity found!

Corot Week 6 4

Ground-based photometry + variability(Fabregat, Gutierrez-Soto, Suso)

Stromgren photometry at the 0.9m in Granada (6 weeks) for variability: detection of variability, periodicity and even multiperiodicity for HD 168797 and HD 179405

uvby photometry + narrow filters (H, H) at the 1.5m in Calar Alto (3 weeks) to search for faint Be stars in the exoplanet fields

See Gutierrez-Soto et al. 2003 and posters!

Corot Week 6 5

Spectroscopy: GAUDI

for 6 < V < 8 spectra in GAUDI

17 new Be stars discovered in GAUDI (Neiner, Hubert & Catala, 2004)

But:

No spectrum if V > 8

Does not allow variability study

Corot Week 6 6

Additional spectroscopy + variability(Hubert, Janot-Pacheco, Andrade)

Spectroscopic observations at the 1.5m at OHP (6 weeks)

Spectroscopic observations at the 1.6m at LNA (1 week)

Spectrum for Be stars with V > 8

Detection of variability

Corot Week 6 7

Determination of stellar parameters( Frémat, Neiner, Daflon, Andrade)

Data : GAUDI + OHP + LNA

2 independent determinations: Frémat & Neiner + Daflon & Andrade

~70 Be stars in the eyes of Corot

(See Frémat, Neiner et al. 2004)

26000 3.75 253

Corot Week 6 8

CentreMain target Be target Type V vsini Teff log g Variability

HD 171234+170580 HD 171219 B8e 7.65 300 13590 3.07

HD 171834 HD 171219 B8e 7.65 300 13590 3.07

HD 175726 HD 175869 B9IIIe 5.56 164 11810 3.25

HD 177552 -

HD 181555+180642 HD 181231 B9Ve 8.58 250 13658 3.73

HD 181367 B8e 9.36 279 13500 3.65

Only late Be stars in these primary targets fields.

Results for primary fields

Corot Week 6 9

Anticentre

Main target Be target Type V vsini Teff log g Variability

HD 43318 -

HD 43587 HD 43285 B6Ve 6.07 240 14000 3.78 0.45 d

HD 43913 A0e 7.88

HD 45067 -

HD 46558 HD 45901 B2Ve 8.8 164 26518 3.73 phot

HD 46484 B1Ve 7.74 120 27000 3.60 3.29 d

HD 47359 B0.5Ve 8.87

HD 49933+49434 HD 49330 B0e 8.92 300 27000 3.82 0.28 d

HD 49585 B0.5Ve 9.13 253 26042 3.75 0.61 d

HD 50209 B9Ve 8.33 180 11809 3.62 0.66 + 0.59 d

HD 50696 B1Ve 8.83 350 21300 3.45 0.31 d

HD 52265 HD 50891 B0pe 8.88 0.54 d

HD 51193 B1Vnne 8.06 215 22994 3.62 0.61 + 5.5 d

HD 51404 B3e 9.3 342 22500 4.2 0.37 d

HD 51452 B0IIIne 8.08 298 29887 3.88 spec

Corot Week 6 10

Centre: 5 possible late Be stars including 3 well positioned next to the primary targets

no early Be stars

Anticentre: 3 possible late Be stars including 3 well positioned next to the primary targets

10 possible early Be stars including 3 well positioned next to HD 52265

TOTAL:

18 possible Be stars (8 late, 10 early) including 9 well positioned (6 late and 3 early)

Corot Week 6 11

Field HD 171234 + HD 170580

171219

Corot Week 6 12

Field HD 175726

175869

Corot Week 6 13

Field 181555 + HD 180642

181367

181231

Corot Week 6 14

Field HD 43587

43285

43913

+ HD 43913

Corot Week 6 15

Field HD 46558

+ HD 4735946484

45901

47359

46484

Corot Week 6 16

Field HD 49933 + HD 49434

50209

49330

49585

50696

3 early Be stars outside the CCDs with this position of the CCDs

Corot Week 6 17

Field HD 52265

+ HD 50891

51404

51193

51452

50891

Corot Week 6 18

HR diagram of Be secondary targets

Apparent Location

+ 4 Be stars

Corot Week 6 19

HR diagram of Be secondary targets

Rotation effect

c = 0.95

+ 4 Be stars

Corot Week 6 20

+ 2 Be stars in the CCDs+ 2 Be stars

HR diagram of Be secondary targets

Real Location

= in the CCDs

Corot Week 6 21

Results for exploratory fields

~ 60 possible Be targets for exploratory fields

It is better to concentrate on early Be stars, since we have very few early Be stars as secondary targets

2 already detected with multiperiodicity (Fabregat et al.) : HD 168797 (B3e) and HD 179405 (B5e)

Targets in non-selected primary fields have been well studied easier candidates

Corot Week 6 22

Conclusions We need early and late Be stars as secondary targets: 2 different science goals

We found variability, periodicity and even multiperiodicity in most of the Be stars, in spectroscopy and in photometry

We plan to search for magnetic fields with Espadons (CFHT) for the Be secondary targets (starting Feb. 2005)

We have 9 out of 18 Be stars (possible secondary targets) which are well positioned in the CCDs, but 6 late and only 3 early

We need to concentrate on early Be stars for the exploratory fields

We already have 2 very interesting exploratory candidates