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4. Results and discussion

 

ADS Latest tex2html_wrap_inline1344 tex2html_wrap_inline1346 tex2html_wrap_inline1348 tex2html_wrap_inline1350 tex2html_wrap_inline1352
number orbit ('') ('') (tex2html_wrap_inline1358) (tex2html_wrap_inline1358)
434 Heintz 1995 0.440 tex2html_wrap_inline1362 0.015 0.463 192.5 tex2html_wrap_inline1362 0.5 193.2 0.14 tex2html_wrap_inline1362 0.05
1615 Scardia 1983 1.99 tex2html_wrap_inline1362 0.03 1.847 276 tex2html_wrap_inline1362 1 274.3 0.095 tex2html_wrap_inline1362 0.090
1860 Heintz 1996 3.018 tex2html_wrap_inline1362 0.010 2.55 231 tex2html_wrap_inline1362 1 231.9 1.67 tex2html_wrap_inline1362 0.06
Heintz 1996tex2html_wrap_inline1380 2.555 231.7 1.67 tex2html_wrap_inline1362 0.06
2616 Luyten 1934 0.700 tex2html_wrap_inline1362 0.030 0.732 1 tex2html_wrap_inline1362 1 1.328 -
Scardia 1985 0.640 356.5
2755AB Wierzbinsky 1956 - 0.118 - 83.12 -
3358AB Hartkopf et al. 1996 0.245 tex2html_wrap_inline1362 0.010 0.258 170.0 tex2html_wrap_inline1362 0.5 170.3 0.55 tex2html_wrap_inline1362 0.10
3358AC 0.830 tex2html_wrap_inline1362 0.030 0.713* 204.0 tex2html_wrap_inline1362 0.5 204.5* 1.30 tex2html_wrap_inline1362 0.15
3358BC 0.585 tex2html_wrap_inline1362 0.020 212.5 tex2html_wrap_inline1362 0.8 0.95 tex2html_wrap_inline1362 0.20
3711 Baize 1969 0.76 tex2html_wrap_inline1362 0.13 0.743 323 tex2html_wrap_inline1362 1 331.3 -
3728 Muller 1963 - 0.218 - 357.0 -
4115 Siegrist 1951 1.090 tex2html_wrap_inline1362 0.005 1.030 47.2 tex2html_wrap_inline1362 0.5 40.92 1.55 tex2html_wrap_inline1362 0.20
5447 Baize 1992 0.345 tex2html_wrap_inline1362 0.045 0.387 218 tex2html_wrap_inline1362 1 221.1 -
5925 Mourao 1966 0.600 tex2html_wrap_inline1362 0.015 0.727 281.6 tex2html_wrap_inline1362 1.3 282.5 -
7307 Arend 1953 1.017 tex2html_wrap_inline1362 0.005 1.038 279.6 tex2html_wrap_inline1362 0.5 281.7 0.25 tex2html_wrap_inline1362 0.15
8035 Couteau 1958 0.565 tex2html_wrap_inline1362 0.015 0.623 233 tex2html_wrap_inline1362 1 240.9 1.78 tex2html_wrap_inline1362 0.09
Heintz 1956 0.435 225.8
10360 Hartkopf et al. 1989 0.132 tex2html_wrap_inline1362 0.005 0.138 289.3 tex2html_wrap_inline1362 0.5 108.0 0.05 tex2html_wrap_inline1362 0.10
12973 Hartkopf et al. 1989 0.226 tex2html_wrap_inline1362 0.005 0.230 157.5 tex2html_wrap_inline1362 0.5 157.3 0.65 tex2html_wrap_inline1362 0.15
14073 Hartkopf et al. 1989 0.220 tex2html_wrap_inline1362 0.005 0.199 287 tex2html_wrap_inline1362 1 278.9 0.88 tex2html_wrap_inline1362 0.06
14773 Hartkopf et al. 1996 0.270 tex2html_wrap_inline1362 0.015 0.270 27.65 tex2html_wrap_inline1362 0.5 27.5 0.83 tex2html_wrap_inline1362 0.08
14787 Heintz 1970 0.787 tex2html_wrap_inline1362 0.010 0.733 337.8 tex2html_wrap_inline1362 0.5 340.3 3.00 tex2html_wrap_inline1362 0.05
15281 Hartkopf et al. 1989 0.086 tex2html_wrap_inline1362 0.005 0.088 193.5 tex2html_wrap_inline1362 0.5 199.2 0.08 tex2html_wrap_inline1362 0.08
16057 Heintz 1991 0.250 tex2html_wrap_inline1362 0.015 0.255 110 tex2html_wrap_inline1362 1 111.1 0.1 tex2html_wrap_inline1362 0.1
Table 2: Table of measurements. Predicted values of tex2html_wrap_inline1164 and tex2html_wrap_inline1126 are computed from the latest orbits available. Two orbits were given by Heintz for ADS1860. Two orbits are also given for ADS8035 because the latest one does not fit the measured position. Magnitude differences were measured with the probability density functions and are given in the color bands of Table 1

*: Orbit of 2 Cam ABxC. tex2html_wrap_inline1478: 2 orbits proposed.  

  figure210
footnotesize 1: 1st orbit given by Heintz.
2: 2nd orbit given by Heintz.
3: Couteau 1958. 4: Heintz 1956
5: Luyten 1934.
Figure 5: Table on the left gives the residuals in separation (tex2html_wrap_inline1554) and position angle (tex2html_wrap_inline1556). Figure on the right is a graphics visualization of the residuals in a tex2html_wrap_inline1558 plane. Each measurement corresponds to a point in the graph. Error bars in tex2html_wrap_inline1164 and tex2html_wrap_inline1126 have been drawn to scale. For c Her (ADS 10360) the residual in tex2html_wrap_inline1126 has been taken as 1.3tex2html_wrap_inline1358 for the plot (instead of 181.3tex2html_wrap_inline1358)

The measurements are summarized in Table 2 (click here). Positions are compared with those computed from the latest available orbits. Orbital elements are from the catalog of Worley & Heintz (1983) and the Sky Catalogue 2000 Vol. 2 for orbits prior to 1984. Recent orbital elements were found on the home page of Pr. W. Heintz (http://laser.swarthmore.edu/html/ research/heintzr.html) and in the literature (references are given in Col. 2).

This paper presents the first extensive application of speckle techniques based on the probability density functions of specklegrams. This method developed at Nice university is well adapted to the data reduction of binary star speckle data. Relative photometry computed this way (cf Sect. 3.4) is found to be consistent with direct image reconstruction from bispectral techniques (cf Sect. 3.5).

The residuals in tex2html_wrap_inline1164 and tex2html_wrap_inline1126 are given in Fig. 5 (click here). The cloud of points around tex2html_wrap_inline1576 validates the data reduction. It can however be noticed that several stars are found far from the expected position computed from the latest available orbit. Clearly some published orbits have to be reconsidered. This is the case for ADS 3711 (orbit estimated in 1969, period P=199y), ADS 4115 (1951, P=586y), ADS 5925 (1966, P=512y) and ADS 8035 (Couteau Orbit: 1958, P=44.7y (Sky Cat. 2000) - Heintz orbit: 1956, P=44.4y (Worley & Heintz 1983)).

The stars ADS 5447 and ADS 14073 are also found far from their expected position, although the orbits are quite recent (1989 for ADS 14073, 1992 for ADS 5447). More observations are clearly needed before giving a conclusion.

For the star ADS 2616, we have computed the position from the ephemeris of Luyten (1934) and Scardia (1985). Surprisingly, we found that the 1934 orbit does better fit the observed position.

The case of c Her (ADS 10360) is interesting since we found a residual of 181.3tex2html_wrap_inline1358 on the position angle resulting from a confusion between components A and B. This may occur when the magnitude difference is close to zero: measurements of c Her available at the CHARA catalog ( http://www.chara.gsu.edu/CHARA/chara.html) show sometimes a 180tex2html_wrap_inline1358 uncertainty on tex2html_wrap_inline1126 between successive observations. One could object that our observation was made in the red domain, but the spectral types of the two stars are identical (A9 IV) (which should be further investigated), and the brighter star of the couple is the same whatever the color. ADS 10360 needs to be observed again in several color bands for confirmation and to check whether the problem comes from a poor observation or a difference of spectral type of the two binary components.

Acknowledgements

The authors whish to thank the technical staff of the TBL: André Augé, Christian Decha, Pierre Déréthé, Christian Duthu, Francis Laccassagne, Jean-Marie Lavie-Cambo and Christian Lucuix (Observatoire Midi-Pyrénées) for help during the observations; Michel Aurière (Observatoire Midi-Pyrénées) and Institut National des Sciences de l'Univers for financial support. Thanks are also due to Pr. Wulff Heintz for helping in using the orbital elements from his database. This work made use of the SIMBAD astronomical database and of the CHARA 3rd catalogue of interferometric measurements of binary stars.


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