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J/A+AS/127/277      Rotation and binary rate among giant F stars  (Kunzli+ 1998)
Are metallic A-F giants evolved Am stars?
Rotation and rate of binaries among giant F stars
      Kuenzli M., North P.
     <Astron. Astrophys. Suppl. Ser. 127, 277 (1998)>
     =1998A&AS..127..277K      (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Stars, F-type ; Stars, giant ;
              Radial velocities
Keywords: stars: binaries: spectroscopic - stars: chemically peculiar -
          stars: evolution - stars: rotation - stars: Delta Scuti

Description:
    We have tested the hypothesis of Berthet (1991A&A...251..171B) which
    foresees that Am stars become giant metallic A and F stars (defined by
    an enhanced value of the blanketing parameter δm2 of the Geneva
    photometry) when they evolved. If this hypothesis is right, Am and
    metallic A-FIII stars need to have the same rate of binaries and a
    similar distribution of vsini. From our new spectroscopic data and
    from vsini and radial velocities in the literature, we show that it is
    not the case. The metallic giant stars are often fast rotators with
    vsini larger than 100 km/s, while the maximum rotational velocity for
    Am stars is about 100 km/s. The rate of tight binaries with periods
    less than 1000 days is less than 30 % among metallic giants, which is
    incompatible with the value of 75 % for Am stars (Abt & Levy,
    1985ApJS...59..229A). Therefore, the simplest way to explain the
    existence of giant metallic F stars is to suggest that all normal A
    and early F stars might go through a short "metallic" phase when they
    are finishing their life on the main sequence. Besides, it is shown
    that only giant stars with spectral type comprised between F0 and F6
    may have a really enhanced δm2 value, while all A-type giants
    seem to be normal.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table2            30       54   Radial velocities of standard stars
table3            30      236   Radial velocities of A and F giants
table6            80      148   Discussion about the duplicity of all
                                  photometric metallic F giant stars of
                                  Hauck (1986A&A...155..371H)
tables.tex       147      901   LaTeX version of the tables


Byte-by-byte Description of file: table2 table3

   Bytes Format Units   Label     Explanations

   1-  6  I6    ---     HD        HD number (1)
   8- 18  F11.3 d       HJD       Heliocentric Julian day
  20- 25  F6.2  km/s    RV        Radial velocity
  27- 30  F4.2  km/s    e_RV      rms uncertainty on RV

Note (1): Average values of radial velocity for table2 stars:

              ------------------------
                 Star        <Vr>
              ------------------------
              HD    693   15.44±0.36
              HD  22484   27.86±0.44
              HD  89449    5.84±0.52
              HD 114762   47.77±0.26
              HD 136202   54.39±0.27
              HD 187691   -0.27±0.49
              HD 222368    5.12±0.45
              ------------------------


Byte-by-byte Description of file: table6

   Bytes Format Units   Label     Explanations

   1-  6  I6    ---     Name      ? HD number
   8-  9  I2    ---     NTot      Total number of lines for the reference
  11- 12  I2    ---     Nline     Running line number in range [1,Ntot]
  14- 80  A67   ---     Com       Comments (1)

Note (1): References:
             Abt (1965ApJS...11..429A)
             Abt (1969ApJS...19..387A)
             Abt & Biggs, 1972, Bibliography of Stellar Radial  Velocities,
                           Latham Process Corp., New York
             Abt & Levy (1976ApJS...30..273A)
             Adams et al. (1929ApJ....70..207A)
             Breger (1979PASP...91....5B)
             Buscombe & Morris (1958MNRAS.118..609B)
             Campbell (1913LicOB...7..113C)
             Campbell (1928PLicO..16.....C)
             Cannon (1920PDO.....4..253C)
             Catchpole et al. (1982RGOB..188....5C)
             Evans (1961RGOB...44..351E)
             Evans (1966RGOB..110..185E)
             Evans et al. (1961RGOB...48..389E)
             Evans et al. (1964RGOB...85..207E)
             Evans et al. (1957MNRAS.117..534E)
             Frost et al. (1929PYerO...7....1F)
             Harper (1937PDAO....7....1H)
             Henroteau (1923PDO.....8...59H)
             Jones & Haslam (1969RGOB..155...19J)
             Mayor & Mazeh (1987A&A...171..157M)
             Nelson & Kreidl (1993AJ....105.1903N)
             Neubauer (1930LicOB..15...47N)
             Nordstroem & Andersen (1985A&AS...61...53N, Cat. III/127)
             Penfold (1971PASP...83..497P)
             Rodriguez et al. (1994A&AS..106...21R)
             Rosvick & Scarfe (1991PASP..103..628R)
             Sanford & Karr (1942ApJ....96..214S)
             Shajn & Albitzky (1932MNRAS..92..771S)
             Smith (1982ApJ...254..242S)
             Wilson & Joy (1950ApJ...111..221W)
             Wooley et al. (1971ROAn...14....1W)


Acknowledgements: Marc Kunzli 

(End)                                    Francois Ochsenbein [CDS]   15-Jul-1997