EDP Sciences
Free Access
Issue
A&A
Volume 562, February 2014
Article Number A84
Number of page(s) 21
Section Stellar atmospheres
DOI https://doi.org/10.1051/0004-6361/201322762
Published online 11 February 2014

Online material

Table 1

List of the 47 targets, with their derived parameters: rotational velocities, microturbulent velocity ξt, effective temperature, gravity, luminosity and limb-darkening coefficient ϵ in the B band.

Table 2

List of observations and barycentric radial velocity measurements (RV) for the target sample.

Table 2

continued.

Table 4

Abundances for the 34 main-sequence targets not identified as contaminated.

Table 5

Probabilities to be CP given by the four different criteria.

Appendix A: Comments on individual stars

All our targets are part of the sample studied by Dworetsky (1974), and 25 of them are analyzed by Ramella et al. (1989). In their paper, Ramella et al. (1989) derive vsini from Fourier profile analysis and flag the stars according to the agreement between the observed profile and a theoretical rotation profile (“1” when agreeing, “0” when disagreeing, in their Table 3). Stars labeled as “0” by Ramella et al. are checked out with our data, and the Fourier profiles are plotted in Fig. A.3.

Gontcharov (2006) published a compilation of radial velocities and our individual measurements are compared with literature data. The 44 stars in common are plotted in Fig. A.1. The Gaussian fit of the histogram of radial velocity differences gives a standard deviation σ = 2  km   s-1. Ten stars show differences larger than 3   σ. They are indicated in Fig. A.1. The three stars of our sample (HD 40446, HD 119537 and HD 176984), that are not present in Gontcharov (2006), are already detected as binaries in our data.

thumbnail Fig. A.1

Comparison of radial velocities between individual values from Table 2 and the compilation from Gontcharov (2006). The error bars are the internal errors and the dashed line is the one-to-one relation. The outliers are indicated by open symbols, together with their HD number.

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HD 1439

could not be undoubtedly classified as a normal nor CP star, the derived memberships based on 10 and 14 elements giving contradictory results (Table 5). It moreover lies in the “uncertain” zone in Fig. 9. The derived abundances in oxygen and magnesium are high enough to make it classified as a normal star using all 14 elements whereas the remaining pattern (Si, Ca, Sc, Cr, Fe, Sr, Y and Zr) is rather similar to a CP star. Its radial velocity observed 18 months apart does not show significant variation.

HD 1561

is variable in radial velocity, from our two observations as well as compared with Gontcharov (2006) who gives a radial velocity of − 3  km   s-1 (Fig. A.1).

HD 6530

is detected as a spectroscopic binary from its CCF (Fig. 2). The large difference in the vsini measured using the spectral synthesis and the FT (Table 1) is due to the composite spectrum. It has already been observed by Grenier et al. (1999) who derive the radial velocity and their spectrum is also used by Royer et al. (2002a) to derive the vsini. The CCF from this spectrum is overplotted in Fig. A.2 (black solid line) to emphasize the binary nature of the star.

thumbnail Fig. A.2

Cross-correlation functions for three suspected binary stars. Top panel: the CCF of the observed spectrum is overplotted to the one observed by Grenier et al. (1999). Middle panel: the bisector of the CCF is displayed (dotted line) with a velocity scale enhanced by a factor 3, for the sake of clarity. Bottom panel: the two components in the composite CCF are labeled as “A” and “B”.

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HD 20149

is flagged as a suspected binary due to the asymmetry of the CCF. The bisector is displayed in Fig. A.2. The star is labeled as variable in radial velocity in Gontcharov (2006), and the published value (− 5  km   s-1) is also significantly different from our determinations (Fig. A.1).

HD 21050

is found to have a large projected rotational velocity by Dworetsky (1974) (vsini = 60  km   s-1) but all other determinations are very similar to our result (Palmer et al. 1968; Abt & Morrell 1995; Royer et al. 2002b). Moreover, no spectral variation is detected in our high signal-to-noise observations, collected three years apart.

HD 25175

is suspected by Ramella et al. (1989) to be a spectroscopic binary due to the large broadening and the disagreement the observed profile and a theoretical rotational profile. Their determination of vsini, in good agreement with ours, is much higher than the value derived by Dworetsky (1974) (≤40  km   s-1). Our Fourier profiles are plotted in Fig. A.3a and the agreement with the rotational profile is very good, suggesting that the broadening is dominated by rotation. Also both our spectra, observed one year apart, do not show any sign of radial velocity variation.

thumbnail Fig. A.3

Individual line FT (solid lines) and theoretical rotation profile corresponding to the average vsini (thick dashed line) for the stars flagged as “0” by Ramella et al. (1989): a) HD 25175, b) HD 65900, c) HD 67959, d) HD 72660, e) HD 85504, f) HD 127304, g) HD 145788, h) HD 223386.

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HD 28780

has a vsini significantly different from what Ramella et al. (1989) find (41.3 km   s-1). The radial velocity is moreover significantly different from the value published by Gontcharov (2006): −22.6  km   s-1 (Fig. A.1). Although no evidence of binarity is detected in our single observation, these differences suggest that this object could be a spectroscopic binary.

HD 30085

is discarded from vsini measurement by Ramella et al. (1989) because of asymmetric line profiles. In our classification, it falls in the CP group and is newly detected as chemically peculiar.

HD 33654

is identified as a giant star from both its surface gravity and its luminosity (Table 1), which disagrees with its luminosity class: A0V. It was previously classified as a B9III star (Palmer et al. 1968). It is indicated as an Ap Si star in Renson & Manfroid (2009).

HD 39985

is an outlier in our luminosity comparison (Fig. 3) and therefore suspected to be a binary star.

HD 40446

is flagged as a spectroscopic binary by Dworetsky (1974). It is part of the sample studied by Royer et al. (2002b) who determined an uncertain vsini with a high external error (vsini = 27: ± 5  km   s-1) due to a large dispersion in the values derived from individual lines. Its binary nature is confirmed by the shape of its CCF in Fig. 2.

HD 46642

is suspected to be a photometric variable star (Kukarkin et al. 1981). Our radial velocity measurements reveal a variation hence this star is suspected to be a binary.

HD 47863

shows a significant difference between our measurements of vsini, using spectral synthesis and Fourier profile. This object is however used as a reference star in speckle observations by Aristidi et al. (1997), suggesting that it is a single star.

HD 50931

is detected as a spectroscopic binary from the distorted shape of its CCF. The radial velocity from Gontcharov (2006) is moreover very different from our result: 20 km   s-1 (Fig. A.1). The large difference in the vsini measured using the spectral synthesis and the FT (75 and 84 km   s-1 in Table 1, respectively) is due to the composite spectrum.

HD 58142

is found to be a hot Am star by Adelman (1994), which disagrees with our classification. This object lies in the tail of the distribution of memberships (Table 5 and Fig. 8) and could have been wrongly assigned to the “normal” group.

HD 65900

is suspected by Ramella et al. (1989) to be a spectroscopic binary due to the large broadening and the disagreement between the observed profile and a theoretical rotational profile. This disagreement is not seen in our data (Fig. A.3b). In our classification, it falls in the CP group and is newly detected as chemically peculiar.

HD 67959

is found to disagree with a rotation profile by Ramella et al. (1989), but this is very probably due to its low vsini and the fact that instrumental broadening is not negligible. In our data (Fig. A.3c), the main lobe of the FT in observed profiles is well fitted by the theoretical rotation profile. In our classification, it falls in the CP group and is newly detected as chemically peculiar.

HD 72660

is a hot Am star (Varenne 1999), which is consistent with our classification. Its low vsini makes the Fourier profiles dominated by the instrumental profile, both in Ramella et al. (1989) and in Fig. A.3d. It is listed in Table 3 as variable in radial velocity, but the variation remains very small. Landstreet (1998) detects an asymmetry in the spectral lines that is attributed to a depth-dependent velocity field.

HD 85504

is flagged by Ramella et al. (1989) as showing a profile disagreeing with a rotational broadening. In our data however (Fig. A.3e), the agreement with the theoretical rotational profile is good. This object is flagged in Renson & Manfroid (2009) as an Ap Mn star, and manganese is not part of our analyzed chemical species. In Adelman & Pintado (1997), it only appears slightly metal rich compared to other superficially normal stars with similar effective temperature. This object is moreover known as high spacial velocity (Martinet 1970; Altmann & de Boer 2000) which may be a runaway star. It is a suspected variable star (Kukarkin et al. 1981).

HD 95418

is an Am star (Adelman et al. 2011; Hill 1995) and our classification agrees with these results.

HD 101369

is suspected to be a spectroscopic binary from the shape of its CCF (Fig. 2).

HD 107655

belongs to the open cluster Coma Ber. Gebran et al. (2008) derived abundances, using the same method, and their values are in good agreement with our determinations, with larger differences for Sc and Sr. The dispersion in the Sc and Sr abundances derived by Gebran et al. (2008) is high; they include more lines than in this study, especially lines located in the wings of Balmer lines. When restricting the comparison to lines in common, the agreement is much better (Table A.1).

Table A.1

Comparison of Sc and Sr abundances of HD 107655 with Gebran et al. (2008).

HD 119537

is detected as a spectroscopic binary by Dworetsky (1974). The SB2 nature is clearly visible in our CCFs and they are plotted for both observations in Fig. A.2 together with the labels of the components (“A” being the component with the highest correlation peak). The radial velocities given in Table 2 are the one corresponding to component A and the difference in radial velocity (A−B) is 153.4  km   s-1 in the first observation (2006-06-02) and − 140.9  km   s-1 on the second (2012-02-14).

HD 127304

is suspected by Ramella et al. (1989) to be a SB2. Our derived radial velocity is moreover significantly different from the value published by Gontcharov (2006), − 12.6  km   s-1 (Fig. A.1).

HD 132145

is suspected by Ramella et al. (1989) to be a spectroscopic binary. The observed variation in radial velocity in our data is not significant taking the instrumental offset between both spectrographs into account.

HD 133962

is suspected to be a photometric variable star (Kukarkin et al. 1981).

HD 145647

is suspected to be a binary star from the shape of the CCF (Fig. 2).

HD 145788

is studied by Fossati et al. (2009) who do not detect clear signatures of chemical peculiarity and believe this object is a normal star whose abundance pattern reflects the composition of its progenitor cloud. It is flagged by Ramella et al. (1989) as showing a profile disagreeing with a rotational broadening, probably due to the small rotational broadening. In Fig. A.3g, the shape of the main lobes of the observed profiles agree with the theoretical rotation profile. This star was only observed with ÉLODIE and in our classification, it falls in the normal group. In the sample, it is the normal star with the smallest vsini.

HD 156653

is indicated as a spectroscopic binary by Dworetsky (1974). Our radial velocity measurements show a ratio of the external error over the internal error just above the threshold used to identify variations in Table 3.

HD 158716

is suspected by Ramella et al. (1989) to be a spectroscopic binary. In our classification, it falls in the CP group and is newly detected as chemically peculiar.

HD 172167

is, strangely enough, an outlier in Fig. A.1, where Gontcharov (2006) gives a radial velocity of − 20.6  km   s-1. Vega is not known to have a variable radial velocity on such a scale.

HD 174567

is suspected by Ramella et al. (1989) to be a variable CP star (strong Si and variable Sr). It is classified as a normal star according to our measurements but we detect a variation in radial velocity, strengthened by the comparison with Gontcharov (2006) in Fig. A.1.

HD 176984

is suspected to be a spectroscopic binary from the variability of its radial velocity (Table 3).

HD 183534

is detected as a spectroscopic binary from the shape of its CCF (Fig. 2) and the difference in radial velocity with Gontcharov (2006) in Fig. A.1.

HD 196724

is suspected to be a spectroscopic binary from the variability of its radial velocity (Table 3).

HD 199095

is detected as a spectroscopic binary by Dworetsky (1974). Our measurements show a variation in radial velocity, confirmed when comparing with data from Gontcharov (2006) in Fig. A.1.

HD 217186

is considered to be a possible magnetic field candidate by Schröder et al. (2008) after being associated with a ROSAT X-ray source (Schröder & Schmitt 2007) as a bona fide single star. This object is however suspected to be a binary from the shape of its CCF (Fig. 2). We have only one spectrum for this object, but the comparison with Gontcharov (2006), in Fig. A.1, suggests a variation in radial velocity.

HD 219290

is listed as “uncertain” in Table 5 and lies in the “uncertain” zone in Fig. 9. The high abundances in carbon and oxygen produce contradictory classifications when 10 and 14 are used. The remaining pattern (Si, Ca, Sc, Cr, Fe, Ni, Sr and Zr) is rather similar to a CP star.

HD 219485

is listed as “probably normal” in Table 5. It is marginally classified as a CP star based on the 10 “classical” elements. The abundances in Ni and Sr are however significantly higher than the median values in the normal star pattern displayed in Fig. 10.

HD 223386

is flagged as disagreeing from a rotation profile by Ramella et al. (1989), but the agreement is very good in our data (Fig. A.3h).

HD 223855

is indicated as a spectroscopic binary by Dworetsky (1974). It shows a significant difference between the measurements of vsini using spectral synthesis and Fourier profiles, and both values are significantly higher than the one derived by Dworetsky (1974): 45  km   s-1.

Appendix B: Linelist

The analyzed spectral lines are listed in Table B.1, sorted by chemical element and central wavelength, together with the adopted oscillator strength.

Table B.1

Atomic data and their reference for the lines used in our abundances determination.


© ESO, 2014

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