Submission to Journal of Double Stars Observations Measurements of close visual binary stars at the Observatory of Saint-Véran J. Sérot jocelyn.serot@free.fr J.E. Communal jec@raptorphotonics.com Abstract: This paper gives the results of observations of close visual binary stars carried out in July 2016 and August 2017 at the Observatory of Saint-Véran, in the French Alps, using 62 cm and 50 cm reflector telescopes. Measurements of 43 pairs, with separations between 0.25 and 1.25 arcsec and magnitudes up to 12.1 are listed, including O-C residuals for 8 pairs listed in the Sixth Catalog of Orbits. For 23 pairs, the image sequences have been reduced using three distinct methods : lucky stacking, auto-correlation and bispectrum analysis, providing an estimation of the applicability and the accuracy of the latter both for in terms of astrometry (separation and position angle) and photometry (difference in magnitudes between the two components). Keywords: Astrometry; Stars; Binaries; Visual ; Bispectrum 1. Introduction The Observatoire de Saint-Véran (Observatory of SaintVeran) is a French astronomical observatory located on the Pic de Château Renard in the municipality of SaintVeran in the department of Hautes-Alpes in the French Alps. At 2930 m altitude, it is the highest observatory in Europe (Fig. 1). The observatory was built in 1974 as a branch of the Paris Observatory after a ten years campaign to choose the best location to erect a 4m class telescope. When this project was finally abandoned in 1989 - due to the installation of the Canada-FranceHawaii Telescope in Hawaii -, the Astroqueyras Amateurs Association was set to take over the astronomical observational site and granted use of the 62 cm Cassegrain telescope. Since then, three other instruments have been installed at the observatory : a 20 cm F/4 Flat Field Camera and two 50 cm F/8 Ritchey-Chretien telescopes. The members of the association are conducting observational missions covering a large panel of activities : visual observation and astronomical sketching, planetary and deep sky imagery, astrometry and photometric analysis, stellar spectroscopy, supernovae and cometary searches, asteroid surveillance, exoplanetary transits, etc. But, quite surprizingly given the exceptional seeing frequently recorded at the observatory very few missions have been devoted to the observation and measurement of visual double stars. We had the occasion to spend two weeks at the observatory, in July 2016 and Aug 2017. This paper gives the results of these short campaigns. The 50 cm Ritchey-Chretien telescope (Fig. 3) is installed under a 4.5 m dome (right, on Fig. 1) on AP1600 equatorial mount controled using the SKYCHART software. Two different cameras were used : A Raptor Kite EMCCD (in Aug. 2017) and a ZWO ASI290MM (in Jul. 2016 and Aug. 2017). These cameras have been described in previous papers ([1],[2]). On the Cassegrain telescope only the ASI290 camera was used. Its small pixels allowed us to work at prime focus of the instrument, with a plate scale of 0.06378 arcsec/pixel (F=9m, pixel size=2.9 μm). On the RC telescope (F=4m), two optical configurations were used : - a 2x barlow when working with the ASI290 camera, giving a resulting focal length of 8.4m and a plate scale of of 0.0717 arcsec/pixel - a 10 mm projecting eyepiece with the Raptor Kite camera, giving a resulting focal length of 27.9 m and a plate scale of of 0.0738 arcsec/pixel Three types of filters were used: a broad 400-700 nm filter, a 580-670 nm red filter and a 490-570 nm green filter (Astronomik L, R and G, resp.). No atmospheric dispersion corrector (ADC) was used. Acquisition was carried out with the Genika software [3]. 2. Instrumentation The results reported in this paper have been obtained with two different instruments : A 62 cm Cassegain telescope (in July 2016) and a 50 cm Ritchey-Chretien telescope (in August 2017). The Cassegain telescope (Fig. 2) is installed under a 7.5 m dome (left, on Fig. 1). It has a focal length of 9 m (F/D=15). The equatorial mount is controled by a dedicated software, run from a remote room. Fig 1 The Observatoire de Saint-Véran, altitude 2930m p 1/10
Submission to Journal of Double Stars Observations For all sessions, calibration was carried out using the sideral drift method using the dedicated module of the SPECKLETOOLBOX software [4], the precise datation of each frame being performed by the Genika software. As reported in [2], this method provides very accurate and reproducible results both for plate scale and camera angle estimation. Fig. 4 illustrates the analysis of a single sideral drift with the tool. The graphics plots the X-Y positions of the detected star for the whole sequence (450 positions here, for a sequence duration of approximately 5 s). The green line correspond to the best linear approximation. The camera angle is deduced from the slope of this line, whereas plate scale (in arcsec/pixel) is deduced from the mean of the differences in successive X and Y positions. In each observing night, between 4 and 12 drifts were recorded and the final calibration values are obtained by computing the statistical mean of the extracted values. As an indication, Table 1 gives the values extracted from eight sideral drifts, on two stars, in the night of Aug 29 2017. The final calibration values obtained from this data set are E=0.07117±0.0001 arcsec/pixel and Δ=176.0±0.1. Lucky stacking (LS) was here only used to obtain an estimation of the difference in magnitude (ΔM) of the two components. The n best images of each acquisition sequence (n=10-30 typically) are selected and co-added and then measurement is carried out on the composite image using a dedicated surface fitting algorithm («Surface») provided by the REDUC software. Each observing night, the selection of targets and their pointing was carried out using the WDSPICK tool described in [5]. Fig 3 The 50 cm Ritchey-Chretien telescope Fig 2 The 62 cm Cassegrain telescope 3. Data reduction The data collected in July 2016 were analysed with the REDUC sotware [5] using the auto-correlation module to obtain angular separation (SEP) and position angle (PA) as described in [2]. The data collected in August 2017 were analysed using three different reduction methods : lucky stacking, autocorrelation and bispectrum analysis. Fig 4 The Drift analysis module of SpeckleToolBox at work for extraction of calibration parameters p 2/10
Auto-correlation-based reduction (AC) sometimes called speckle interferometry 1 has been described in [1] and [2]. It consists in computing the power spectrum of individual images (taking the square of the modulus of the Fourier transform), summing these power spectrums and computing the inverse Fourier transform of the sum. The SEP and PA values of the measured pair are then deduced from the position of the peaks on the resulting auto-correlogram. Both the applicability and the precision of the method can be significantly improved by using deconvolution. Deconvolution consists in dividing the accumulated power spectrum by that obtained from a sequence of a single star 2 observed under the same conditions (typically as close as possible in time and celestial position to the target star). We performed ACbased reduction both with REDUC (on the data obtained in 2016) and with SPECKLETOOLBOX version 1.08 (on the data obtained in 2017). Bispectrum (BS) analysis also known as triplecorrelation is a powerful technique aiming at recovering the final image phase in the Fourier domain that is lost when using classical auto-correlation techniques. This allows a representation of the original set of images to be reconstructed with atmospheric distortion removed. As for simple AC techniques, bispectrum analysis is more effective when used with a reference (single) star. The power spectrum and bispectrum are computed for the reference star and are then used to compensate the power spectrum and bispectrum of the target double star. Contrary to AC, the method allows a direct estimation of ΔM. We used the BS analysis modules provided by SPECKLETOOLBOX version 1.13. The procedure is executed in two steps. One first constructs the bispectrum from the average of the triple correlation of each image in the ensemble. This process is computationally intensive, typically taking 10 times more CPU time than the computation of the power spectrum alone. The second step is the reconstruction of the final image from the power spectrum and bispectrum. This step, which iterates the image phase until convergence, is usually quite fast. During this step the user can apply filters and photon bias removal in the Fourier domain to improve the SNR of the final image. This second step is illustrated on Fig. 5. The top image shows the reconstructed final image and the lower image the two control panels used both for computing it and for performing measurements on it. The target star here is BU 1263. Reconstruction has been performed using star UCAC4-465-132365 as reference. On the reconstructed image, the yellow, green and pink circles respectively indicate the area from which the background level is estimated and the location of the primary and secondary component. The pair is here measured has having a a separation of 0.541 arcsec, a position angle of 194.34 (taking into account the indicated calibration values) and a difference of magnitude of 1.47. 1 Though, strictly speacking, the term speckle interferometry only applies when the input images show a sufficient high number of speckles, i.e. when D/R0 >> 1 ; in other cases, the technique should rather be called pixel auto-correlation. 2 Called the reference star Fig 5 The bispectrum analysis module of SPECKLETOOLBOX at work 4. Results Due to bad weather conditions and because the instruments were also used for other targets, we could only devote four nights to double stars observations : Jul 18-19, 2016 and Aug 28-29, 2017. Results are given in Tables 2 and 3. In Table 2, columns 1-10 respectively gives - the identifier of the star in the WDS catalog [7] p 3/10
- its discoverer code - the magnitudes of the primary and secondary component, as reported in the WDS catalog - the final PA and SEP measurement (in degree and arcsec, resp.) with estimated error when available 3 - the estimated difference of magnitude, when available - the number of individual measurements, - the date of measurements - some notes, to be detailed after the table Table 3 gives detailed measurements showing results obtained with each of the three reduction methods listed in Sec. 3 for pairs observed in 2017. Measurements are given in column blocks named SEP, PA and ΔM. In each block, sub-blocks AC, BS and LS refer to results obtained with auto-correlation, bispectrum analysis and lucky stacking respectively. Individual columns named μ, σ and N respectively give the statistical mean, standard deviation and number of samples. The last column block (labeled COMPARISON) compares the results obtained for SEP and PA with the AC and BS methods on the one hand and those obtained for ΔM with the BS and LS methods on the other hand. The individual columns here give the difference between the values obtained by the corresponding methods. For PA, the maximum difference (in absolute value) is 4.6. The statistical mean of the difference is 0.40 and its standard deviation is 1.8. For SEP, the maximum difference (in absolute value, again) is 0.06 arcsec, the statistical mean is -0.01 arcsec and the standard deviation is 0.023 arcsec. This demonstrates that, as long as astrometry is concerned, both the accuracy and the precision of the results produced by bispectrum analysis are comparable with those obtained with «classical» auto-correlation method. For ΔM, the maximum difference is 1.3, the statistical mean is 0.21 and the standard deviation is 0.43. Dispersion is clearly higher here and the mean value could indicate a systematic bias. It can be noted, however, than estimating magnitudes for very close pairs (as is the case here) is notoriously difficult because the estimation has to take into account the sky background and the presence of the diffraction rings. Typical post-reduction images (LS, AC and BS) are given on Plate 1. All LS images (left column) were computed by the REDUC software. The AC images in the first two rows (in color) were also computed by the REDUC software. All other images (AC and BS) were computed by the SPECKLETOOLBOX software. For pairs having a known orbit, Table 4 gives the O-C residuals, computed from the ephemerides published in 3 The error is obtained by dividing the standard deviation, computed from all the individual measurements by the square root of the number of measurements. Submission to Journal of Double Stars Observations p 4/10 the 6th Catalog of Orbits [8]. Only two pairs show significant O-C values : A 1249AB and A 2205. For both of them, the deviation, which is very close to 180, is likely to be caused by a component inversion in the computed orbit. The latest measurements in the WDS catalog (240 in 2015 for A 1249AB, 187 in 2010 for A 2205) and the images given in Plate 1 tend to support this interpretation. Several of the pairs observed during this campaign show a significant displacement since their last measurement recorded in the WDS catalog. These pairs are listed in Table 5 (with columns DATE2, DATE, δ SEP and δ PA giving respectively the date of the last measurement in WDS, the date of our measurement and the difference between the measurements in SEP in PA). For HU 490AB, COU2220 and COU2426 the relatively large difference values either in SEP or PA can probably be attributed to the involved time scale (34, 33 and 26 years resp.). For COU1157, the corresponding timescale is unlikely to explain the large discrepancy observed in PA between our observation and the last recorded in the WDS (PA=145.7 in 2007). It can be noted, however, that this last measurement is given with the indication «quadrant flipped 180 from published value» and that all previous recorded observations, obtained between 1974 and 1990 give fluctuating PA values between 92.4 and 111.4. For COU2124, we have no explanation for the large discrepancy observed both for PA and SEP between our observation and the two recorded in the WDS PA/SEP=25.8 /0.31 and PA=36.7 /0.35 resp. except a misidentification. A search for pairs with characteristics compatible with our observation in the neighborhood of COU2124 within the WDS did not produce any hint for a possible confusion, however. Finally, several of the target stars were either viewed as simple or perceived as binaries but cannot reliably measured because their separation was too close (<0.25 arcsec typically). These stars are listed in Table 6. 6. Conclusion The results reported here confirm the high value of the Observatory of Saint-Véran for high resolution imaging, with reliable measurements of visual double stars close to the diffraction limit of the instruments being easily obtained. This was in fact already known in the field of planeraty imaging but, as stated in the introduction, has never been demonstrated to the best of our knowledge in the field of close visual double star observation and measurement. These results also show that bispectrum analysis a technique which has very rarely been exploited in the amateur domain produces results which are, in terms of precision and accuracy, on the par with those obtained with other reference methods, such as pixel autocorrelation or speckle interferometry, at least for astrometry. Results in terms of photometry (DeltaM estimation) are also very encouraging, although some work probably remains to be done to further assess the accuracy of the measurements.
Acknowledgments The authors would like to thank the AstroQueyras association for observation time on the instruments and, more generally, for providing access to the observatory to the amateur community. This research has made use of the Washington Double Star and 6th Orbit catalogs maintained at the U.S. Naval Observatory. The history of measurements for COU2124 and COU1157 have been kindly provided by B. Mason. Data reduction was carried out using the REDUC software, developed and maintained by F. Losse, and the SPECKLETOOLBOX software developed by D. Rowe. References [1] Sérot, J. Speckle Interferometry of Close Visual Binary Stars with a 280 mm Reflector and an EM-CCD. JDSO, 12, pp 488-499, 2016. Submission to Journal of Double Stars Observations [4] Harshaw R., Rowe D., Genet R. The Speckle Toolbox: A Powerful Data Reduction Tool for CCD Astrometry. JDSO, 13(1), pp 52-67, 2017. [5] Sérot, J. User s Guide to WdsPick. JDSO, 12(6), pp 535-540, 2016 [6] Losse, F. Reduc, v5.0. http://www.astrosurf.com/hfosaf [7] Mason, D.B., Wycoff G.L., Hartkopf, W.I. Washington Double Stars Catalog, USNO, 2015. http://www.usno.navy.mil/usno/a strometry/optical-ir-prod/wds/wds [8] Hartkopf, W.I., Mason, D.B. Sixth Catalog of Orbits of Visual Binary Stars. USNO, 2009. http://www.usno.navy.mil/us NO/astrometry/optical-IR-prod/wds/orb6 [2] Sérot, J. Measurements of close visual binaries with a 280 mm reflector and the ASI 290MM camera. JDSO, 13(2), 2017, pp 268-284. [3] http://genicapture.com p 5/10
Table 1 Raw calibration values extracted from sideral drifts on the night of Aug 29, 2017 N : number of frames in the analyzed sequence ; DIAM : RMS star diameter DELTA, E : infered camera angle ( ) and plate scale (arcsec/pixel) STAR N DIAM DELTA E HD 205852 195 1 175.49 0.07144 195 1 176.13 0.07132 195 1 176.33 0.07066 HD 196724 450 1 176.34 0.07128 450 0.9 175.7 0.07134 450 1 175.9 0.07081 450 1 175.93 0.07147 450 1.1 176.3 0.07107 Table 2 Final results for the four observing nights WDS NAME M1 M2 PA ( ) SEP (arcsec) DeltaM N DATE NOTES 00024+1047 A 1249AB 9.3 9.9 246.8 ± 0.5 0.31 ± 0.008 0.9 ± 0.04 7 2017.655 2a,3,L 00095+1907 COU 247 8.2 9.9 213.2 ± 0.7 0.32 ± 0.011 1.7 ± 0.11 8 2017.655 2a,3,L 00118+2825 BU 255 7.8 8.9 66.0 ± 0.4 0.47 ± 0.003 1.4 ± 0.04 8 2017.655 2a,3,L 00206+1219 BU 1015 8.3 9.6 109.8 ± 0.2 0.51 ± 0.004 0.7 ± 0.04 8 2017.655 2a,3,L 00429+2047 A 2205 10.2 10 181.7 ± 0.6 0.39 ± 0.004 1.7 ± 0.31 8 2017.655 2a,3,L 00470+2315 HU 413 9.2 9.2 329.6 ± 0.8 0.35 ± 0.006 1.4 ± 0.07 8 2017.655 2a,3,L 00520+3154 A 924 9.8 9.9 305,6 ± 1,0 0,38 ± 0,011 1.4 ± 0.29 7 2017.655 2a,3,L 00583+2124 BU 302 6.6 8.7 230.8 ± 0.8 0.30 ± 0.006 1.5 ± 0.07 9 2017.655 2a,3,L 19055+3352 HU 940 9.1 9.7 190.8 ± 0.4 0.44 ± 0.003 5 2016.545 1,3,R 19074+3601 COU1615 11.7 11.7 96.1 ± 0.0 0.41 ± 0.000 5 2016.545 1,4,R 19081+3031 HO 99 9.9 9.9 166.9 ± 0.7 0.39 ± 0.003 6 2016.545 1,R 19132+3420 COU1616 11.6 11.6 132.0 ± 0.1 0.30 ± 0.003 4 2016.545 1,R+G 19134+2926 COU1157 9.8 9.8 95.7 ± 0.9 0.25 ± 0.002 5 2016.545 1,4,G 19147+3258 COU1463 10.8 11.1 207.9 ± 0.4 0.65 ± 0.007 5 2016.545 1,R 19163+4018 COU2280 11.2 11.3 274.7 ± 1.5 0.30 ± 0.004 5 2016.545 1,4,G 19189+3336 HU 1299 10 11.3 344.3 ± 2.4 0.31 ± 0.011 4 2016.545 1,R+G 19208+3711 COU1801 10.5 10.8 337.2 ± 0.8 0.36 ± 0.003 5 2016.545 1,R 19237+3710 COU1938 9.7 10.7 125.1 ± 0.9 0.41 ± 0.008 5 2016.545 1,R 20069+3438 COU2124 11.4 11.6 265.6 ± 0.4 0.97 ± 0.013 4 2016.548 1,4,R 20096+4009 COU2414 10.2 10.2 159.4 ± 0.3 0.31 ± 0.004 4 2016.548 1,R 20144+3501 COU2216 10.7 10.5 206.5 ± 0.1 0.56 ± 0.003 5 2016.548 1,R 20306+3525 COU1961 10.7 10.9 204.6 ± 0.6 0.43 ± 0.001 5 2016.548 1,R 20463+3646 COU2220Aa,Ab 11.4 11.5 298.7 ± 0.3 0.66 ± 0.009 2 2016.548 1,4,R 20495+4035 COU2426 11.1 11.4 327.7 ± 0.0 1.25 ± 0.003 4 2016.548 1,R,4 21008+2057 A 176 10.1 10.1 355.3 ± 0.5 0.26 ± 0.010 1.0 ± 0.23 7 2017.655 2a,L 21021+1423 A 1687 10.4 10.8 189.1 ± 0.1 0.80 ± 0.003 0.7 ± 0.20 8 2017.655 2a,L 21022+1426 A 1688 9.3 9.4 70.1 ± 0.5 0.33 ± 0.004 1.7 ± 0.05 8 2017.655 2a,L 21026+2141 BU 69AB 8.3 9.8 5.9 ± 0.5 0.38 ± 0.003 0.7 ± 0.04 8 2017.658 2b,5,L 21065+2655 COU 527Aa,Ab 9.5 9.8 305.3 ± 0.3 0.32 ± 0.004 0.3 ± 0.04 8 2017.658 2b,4,L 21142+1231 HEI 406 11.5 11.7 179.1 ± 0.1 0.72 ± 0.002 0.7 ± 0.02 8 2017.658 2b,L 21196+1421 HU 962 8.6 9.4 60.8 ± 0.2 0.64 ± 0.006 2.3 ± 0.13 8 2017.658 2b,L 21206+2743 A 295 8.9 9.1 253.2 ± 0.3 0.28 ± 0.003 0.5 ± 0.09 8 2017.655 2a,L 21210+0022 RST5162 9.8 9.9 21.4 ± 0.2 0.41 ± 0.002 0.4 ± 0.04 8 2017.658 2b,L 21225+0827 HU 275 9.4 9.5 56.2 ± 0.2 0.35 ± 0.002 0.2 ± 0.02 8 2017.658 2b,L 21233+1520 HEI 189 11.4 11.4 36.3 ± 0.1 0.59 ± 0.002 0.4 ± 0.04 8 2017.658 2b,4,L 21261-0010 RST5164 11.2 11.3 306.1 ± 0.1 0.90 ± 0.003 0.9 ± 0.04 8 2017.658 2b,L 21287+1810 HU 490AB 9.6 12.1 315.7 ± 0.4 0.36 ± 0.006 1.4 ± 0.10 8 2017.658 2b,4,L 21322+1055 HDS3061 7.4 9 258.7 ± 1.4 0.28 ± 0.006 1.5 ± 0.15 8 2017.658 2b,L 21328+0159 A 2290 9.3 9.8 260.6 ± 0.4 0.49 ± 0.004 0.9 ± 0.07 5 2017.655 2a,4,L 21399+1914 COU 330 8.7 11.3 190.2 ± 1.1 0.47 ± 0.028 2.9 ± 0.1 8 2017.658 2b,5,L 21435+2721 A 299AB 9.9 10.4 64.3 ± 0.1 1.13 ± 0.001 1.4 ± 0.02 8 2017.655 2a,L 21447+0250 BU 1263 9.4 9.9 193.4 ± 0.2 0.54 ± 0.002 1.6 ± 0.04 8 2017.658 2b,5,L 21461+3534 COU1337 10.9 11 109.8 ± 0.4 0.30 ± 0.005 0.8 ± 0.04 8 2017.658 2b,L Notes for Table 2: - 1 : 62 cm Cassegrain + ASI290MM - 2a : 50 cm Ritchey-Chrétien + Raptor Kite - 2b : 50 cm Ritchey-Chrétien + ASI 290MM - 3 : Pair with an entry in 6th Catalog of Orbits. See Table 4 for O-C - 4 : Pair showing a significant displacement since last measure published in WDS. See Table 5-5 : Only one measurement for DeltaM, hence no associated error - L, R, G : used filter (see Sec. 2) p 6/10
Table 3 Detailed measurements showing results obtained with each of the three reduction methods for pairs observed in 2017 SEP PA Δm COMPARISON NAME AC BS AC BS BS LS AC vvs. BS Bs vs. LS µ σ N µ σ N µ σ N µ σ N µ σ N µ N SEP PA Δm A 176 0.23 0.007 3 0.28 0.007 4 355.6 1.18 3 355.1 1.42 4 1.2 0.3 4 0.1 1-0.05 0.5 1.1 A 295 0.28 0.008 4 0.28 0.01 4 253.3 0.56 4 253 0.98 4 0.5 0.2 4 0.7 1 0.00 0.3-0.2 A 299AB 1.13 0.002 4 1.13 0.005 4 64.3 0.11 4 64.3 0.32 4 1.4 0 4 1.5 1 0.00 0-0.1 A 924 0.4 0.016 4 0.35 0.012 3 303.6 0.84 4 308.2 1.36 3 1.7 0.4 3 0.6 1 0.05-4.6 1.1 A 1249AB 0.33 0.003 3 0.29 0.011 4 248.2 0.77 3 245.7 0.6 4 0.9 0.1 4 0.8 1 0.04 2.5 0.1 A 1687 0.79 0.002 4 0.8 0.009 4 189 0.14 4 189.1 0.26 4 0.7 0.5 4 0.6 1-0.01-0.1 0.1 A 1688 0.32 0.008 4 0.33 0.013 4 70.7 1.33 4 69.5 1.51 4 1.7 0.1 4 1.5 1-0.01 1.2 0.2 A 2205 0.38 0.002 4 0.39 0.015 4 180.7 0.56 4 182.6 1.91 4 2.0 0.5 4 0.7 1-0.01-1.9 1.3 A 2290 0.49 0.002 3 0.5 0.013 2 261.3 0.34 3 259.6 0.25 2 1.0 0.1 2 0.8 1-0.01 1.7 0.2 BU 69AB 0.38 0.006 4 0.39 0.009 4 5.4 0.66 4 6.4 2 4 0.7 0.1 4 0.6 1-0.01-1 0.1 BU 255 0.47 0.004 4 0.46 0.007 4 66 1.03 4 65.9 1.04 4 1.4 0.1 4 1.3 1 0.01 0.1 0.1 BU 302 0.29 0.022 3 0.31 0.009 6 230.9 0.68 3 230.8 2.74 6 1.5 0.2 7 1.3 1-0.02 0.1 0.2 BU 1015 0.51 0.001 4 0.51 0.015 4 109.8 0.15 4 109.7 0.75 4 0.7 0.1 4 0.7 1 0.00 0.1 0.0 BU 1263 0.54 0.003 4 0.55 0.006 4 193 0.28 4 193.8 0.34 4 1.6 0.1 4 1.7 1-0.01-0.8-0.1 COU 247 0.29 0.013 4 0.35 0.01 4 212.9 2.39 4 213.4 1.37 4 1.6 0 4 2.2 1-0.06-0.5-0.6 COU 330 0.47 0.108 3 0.47 0.023 4 192.8 1.94 3 188.2 1.99 4 2.8 0.2 4 3.1 1 0 4.6-0.3 COU 527Aa,Ab 0.31 0.002 4 0.33 0.001 4 304.7 0.3 4 305.8 0.87 4 0.3 0 4 0.1 1-0.02-1.1 0.2 COU1337 0.31 0.006 4 0.29 0.014 4 110.1 1.09 4 109.5 0.99 4 0.8 0.1 4 0.7 1 0.02 0.6 0.1 HDS3061 0.27 0.005 4 0.29 0.021 4 260.5 4.02 4 256.9 2.62 4 1.6 0.2 4 0.9 1-0.02 3.6 0.7 HEI 189 0.59 0.002 4 0.59 0.007 4 36.3 0.27 4 36.3 0.29 4 0.4 0.1 4 0.3 1 0.00 0 0.1 HEI 406 0.71 0.002 4 0.72 0.005 4 178.8 0.16 4 179.4 0.2 4 0.7 0 4 0.8 1-0.01-0.6-0.1 HU 275 0.35 0.002 4 0.34 0.003 4 56.6 0.23 4 55.8 0.46 4 0.2 0.03 4 0.3 1 0.01 0.8-0.1 HU 413 0.36 0.004 4 0.33 0.011 4 331.6 0.99 4 327.5 0.94 4 1.5 0.1 4 1.2 1 0.03 4.1 0.3 HU 490AB 0.34 0.004 4 0.37 0.009 4 315.6 0.83 4 315.8 1.53 4 1.5 0.1 4 1.0 1-0.03-0.2 0.5 HU 962 0.62 0.01 4 0.65 0.01 4 60.8 0.57 4 60.7 0.51 4 2.4 0.1 4 1.7 1-0.03 0.1 0.7 RST5162 0.4 0.005 4 0.41 0.003 4 21.8 0.32 4 21 0.07 4 0.4 0.1 4 0.4 1-0.01 0.8 0.0 RST5164 0.9 0.006 4 0.89 0.004 4 306.3 0.18 4 305.9 0.23 4 0.9 0.1 4 0.9 1 0.01 0.4 0.0 Table 4 O-C residuals for pairs having a known orbit NAME WDS DATE O-C PA ( ) O-C SEP (") GRADE REF A 924 00520+3154 2017.655-2.0 0.02 4 Hrt2009 A 1249AB 00024+1047 2017.655 180.3 0.05 4 Zir2003 A 2205 00429+2047 2017.655-177.3 0.06 5 Baz1989a BU 302 00583+2124 2017.655 0.1-0.01 4 Cve2006e BU 1015 00206+1219 2017.655 0.0 0.00 2 Hrt2010a COU 247 00095+1907 2017.655-0.3-0.03 5 Doc2012i HU 413 00470+2315 2017.655 1.2-0.02 5 Ole2003d HU 940 19055+3352 2016.545 1.5-0.02 3 Doc2009g Table 5 Pairs showing a significant displacement since their last measurement NAME WDS DATE SEP PA Ự SEP Ự PA DATE2 A 2290 21328+0159 2017.655 0.49 260.6 0.09-18.4 2000 COU 527Aa,Ab 21065+2655 2017.658 0.32 305.3 0.01-10.7 2007 HEI 189 21233+1520 2017.658 0.59 36.3 0.19-11.7 1997 HU 490AB 21287+1810 2017.658 0.355 315.7 0.04 43.7 1983 COU1157 19134+2926 2016.545 0.25 95.7-0.05-50.3 2007 COU1615 19074+3601 2016.545 0.41 96.1 0.01 11.1 1996 COU2124 20069+3438 2016.548 0.97 265.6 0.57 228.6 2007 COU2220Aa,Ab 20463+3646 2016.548 0.66 298.7 0.06 36.7 1984 COU2426 20495+4035 2016.548 1.25 327.7 0.85 18.7 1991 p 7/10
Table 6 Pairs observed but for which no measure was obtained WDS NAME M1 M2 DATE NOTE 20050+3707 COU2212 11.2 11.5 2016.548 1 00022+2705 BU 733AB 5.8 8.9 2017.655 2 21446+2539 BU 989AB 4.9 5 2017.655 1 21451+3424 COU1186 11.9 11.9 2017.658 3 21166-0037 HDS3029 7.5 11.3 2017.658 1 21355+2427 HU 371 6.8 7.2 2017.658 2 Notes for Table 6: - 1: Viewed as simple - 2: Viewed as elongated but no reliable measurement possible - 3 : No reliable measurement possible Plate 1 Post-reduction images LS AC BS COU 1157 N/A HO 99 N/A p 8/10
Plate 1 Post-reduction images (cont d) LS AC BS A 295 A 2290 COU 247 p 9/10
Plate 1 Post-reduction images (cont d) LS AC BS HU 490AB A 1249AB A 2205 p 10/10