Targets selection

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
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!

3
Photometric variability Hipparcos (Hubert
Floquet )

• Some of the targets observed by Hipparcos
  periodicity found!

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 (Ha, Hb) 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!
5
Spectroscopy GAUDI

• for 6 lt V lt 8 ? spectra in GAUDI
• 17 new Be stars discovered in GAUDI (Neiner,
  Hubert Catala, 2004)
• But
• No spectrum if V gt 8
• Does not allow variability study

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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 gt 8
• Detection of variability

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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
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Results for primary fields
Centre
Main target Be target Type V vsini Teff log g Variability
HD 171234170580 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 181555180642 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.
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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 4993349434 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
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• 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)

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Field HD 171234 HD 170580
12
Field HD 175726
175869
13
Field 181555 HD 180642
181367
181231
14
Field HD 43587
43285
HD 43913
43913
15
47359
Field HD 46558
46484
HD 47359
46484
45901
16
Field HD 49933 HD 49434
? 3 early Be stars outside the CCDs with this
position of the CCDs
17
Field HD 52265
HD 50891
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HR diagram of Be secondary targets
4 Be stars
Apparent Location
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HR diagram of Be secondary targets
4 Be stars
Rotation effect
W/Wc 0.95
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HR diagram of Be secondary targets
in the CCDs
2 Be stars in the CCDs 2 Be stars
Real Location
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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

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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