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THE ASTRONOMICAL JOURNAL, 119 : 2422 õ 2427, 2000 May
( 2000. The American Astronomical Society. All rights reserved. Printed in U.S.A.

ORBITS OF VISUAL BINARIES WDS 13320]3109, 14310[0548, 14492]1013, AND 16384]3514 J. A. DOCOBO,1 Y. Y. BALEGA,2 J. F. LING,1 V. TAMAZIAN,1 AND V. A. VASYUK2
Received 1999 October 22 ; accepted 2000 February 7

ABSTRACT Revised orbits and dynamical data of visual binaries WDS 13320]3109, 14310[0548, 14492]1013, and 16384]3514 are presented. For all systems but WDS 16384]3514, the total mass is derived. Some astrophysical properties of the stars are discussed as well. Key words : binaries : visual õ stars : fundamental parameters
1.

INTRODUCTION

Speckle measurements of double stars obtained with the 6 m telescope of the Russian Special Astrophysical Observatory (Balega et al. 1999) as part of a program of collabo ration with the Observatorio Astronomico Ramon Mar·a Aller (Santiago de Compostela, Spain) have shown the need to revise several orbits. Here we present revised orbits for WDS 13320]3109, 14310[0548, 14492]1013, and 16384]3514. Orbits were calculated by Docoboîs (1985) analytical method, and dynamical parallaxes by the BaizeRomani algorithm (Heintz 1978). The dynamical parallaxes are compared with the trigonometric parallaxes published in the Hipparcos and Tycho Catalogues (ESA 1997), which were used to calculate both masses and absolute magnitudes, apparent magnitudes being taken from the Washington Double Star Catalog, 1996.0 (Worley & Douglass 1997, hereafter WDS). The physical properties of these binaries are also discussed. All four new orbits have previously been announced by IAU Commission 26 (1998, Inf. Circ. 135), but the orbital elements of WDS 13320]3109, 14310[0548, and 16384]3514 in the present article are slightly improved relative to those announced in the circular.
2.

sponds to similar data obtained on 2 mõclass telescopes, and 5 corresponds to the poor quality speckle and other interferometric measurements. Regarding the visual observations, their weights are established by means of a formula where the observer, the telescope, and the number of nights appear ; a maximum value 2.5 can be reached.
3.

RESULTS AND DISCUSSION

METHOD

One of the chief advantages of Docoboîs (1985) analytical method is that it does not require knowledge of the areal constant. The method is based on a mapping from the interval (0, 2n) into the family of Keplerian orbits whose apparent orbits pass through three base points (h , o , t ); i \ 1, 2, ii 3, or, namely, normal places. These base pointsi are taken either coinciding with the most reliable (of high weight) measurements or points belonging to the areas with a maximum of observational evidence in their favor, but do not necessarily coincide with actual observations. If three base points do not belong to the same revolution, then interval (0, 2n) must be replaced by (0, 2nn), being n [ 1 the number of full revolutions from the epoch t to t . The orbit 1 3 that ïts better to all the known measurements is chosen from all generated possible ones. In this sense, it is important to take into account the data weights. Our criterion is similar, in a certain manner, to that used by Mason, Douglass, & Hartkopf (1999) : weight 20 corresponds to the speckle measurements on 4õ 6 mõclass telescopes, 10 correõõõõõõõõõõõõõõõ 1 Observatorio Astronomico Ramon Mar·a Aller, University of Santiago de Compostela, P.O. Box 197, Santiago de Compostela, Spain. 2 Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Karachai-Cherkessia 357147, Russia.

Table 1 lists the base points used for the orbits reported in this paper (the position angle of some points has had an extra 360¡ added in, so as to maintain an increasing or a decreasing sequence). Table 2 lists the calculated orbital elements and their estimated formal errors. Each star is identiïed by its WDS number, its name, and its Aitken Double Star catalog number (Aitken 1932), if any. The last row of Table 2 shows the correction for precession used to refer position angles to the equinox 2000.0. Table 3 shows WDS magnitudes (cols. [2] and [3]) and spectral types (col. [4]) together with the dynamical parallaxes calculated, using these data, from the orbital periods and semimajor axes obtained in this work (col. [5]) ; Hipparcos (ESA 1997) apparent magnitudes (cols. [6] and [7]) and trigonometric parallaxes (with standard errors ; col. [8]) are also given. Table 4 presents ephemerides for each binary for the period 1999õ2008. Table 5 lists all known observations of these stars along with the observers (listed by their WDS discoverer codes) and the discrepancies between the observed position angles and angular separations and those given by the new orbits (values in parentheses in the residuals columns are the calculated position angles and angular separations corresponding to observations for which these data were not reported). Asterisks in Table 5 mark observations that were subjected to a change of quadrant for calculation of the orbit. The improvement of the previous orbits for these pairs in the present article is demonstrated in Table 6 where root mean square (rms) and mean absolute (MA) of residual values for each pair are derived. Only the orbit of the system Wor 24 (Heintz 1998), calculated almost simultaneously with ours, does improve our position angles, but not the separations. Obviously, when deriving the values in Table 6, the criterion mentioned above and corresponding weights have been taken into account. WDS 13320+ 3109, Wor 24 (Docobo & Balega 1998). This pair of red dwarfs was discovered by Worley (1961) in 1960.32 with the 36 inch (0.91 m) refractor of the Lick Observatory, and Worley has since described almost two complete revolutions. Prior to our calculations, four orbits had been published : three by Baize (1976, 1981, 1991), whose orbital periods are 36.0, 20.0, and 21.3 yr, respec2422


ORBITS OF FOUR VISUAL BINARIES
TABLE 1 BASE POINTS h (deg) 303.8 92.4 58.8 268.0 371.0 427.8 153.7 393.2 487.0 46.0 79.0 370.0 o (arcsec) 0.180 0.220 0.341 0.195 0.255 0.104 0.151 0.075 0.182 0.200 0.210 0.116

2423

WDS 13320]3109 ......

t 1984.380 1988.260 1991.330 1976.220 1989.310 1992.460 1985.503 1989.255 1993.197 1973.430 1981.380 1995.440

14310[0548 ......

14492]1013 ......

16384]3514 ......

tively, and one by Starikova (1985), with the period 20.346 yr. In addition, almost simultaneously with the announcement of our orbit by IAU Commission 26 (1998), an orbit with a very similar period, 21.07 yr, was published by Heintz (1998). The parallax value 0A034 obtained photo. metrically by Weis (1993) agrees well both with the Hipparcos value 0A032 and our calculated dynamical parallax . 0A0332 but diers from 0A0428 given in the Yale General . . Catalogue of Trigonometric Stellar Parallaxes (van Altena, Lee, & Hoffleit 1995) for this star. Several photometric color index values have been reported : U[B \ 1.22 (Weis 1993), V [R \ 0.94, and R[I \ 0.70 (Booth, Caruso, & Weis 1988 ; Weis 1993). The spectral type M0 V is given in WDS (on the basis of prism spectra), and K7 V is given in the recent spectral survey of Reid, Hawley, & Gizis (1995). The calculated absolute magTABLE 2 ORBITAL ELEMENTS

Element P (yr) .................. t ....................... e ....................... a (arcsec) ............. i (deg) ................. ) (deg) ................ u (deg) ................ Precession (deg) ...... a b c d Wor 24. RST 4529. A 2983 ; ADS 9397. Cou 985.

WDS 13320]3109a 21.18 ^ 0.30 1986.02 ^ 0.01 0.634 ^ 0.003 0.271 ^ 0.002 153.4 ^ 4.0 103.9 ^ 3.0 257.5 ^ 2.5 [0.0009

WDS 14310[0548b 22.98 ^ 0.30 1993.62 ^ 0.02 0.499 ^ 0.010 0.243 ^ 0.002 49.1 ^ 2.0 13.8 ^ 2.0 121.0 ^ 2.5 [0.0034

WDS 14492]1013c 9.98 ^ 0.04 1988.059 ^ 0.03 0.491 ^ 0.001 0.127 ^ 0.001 45.8 ^ 2.0 142.3 ^ 2.0 156.8 ^ 3.0 [0.0038

WDS 16384]3514d 27.17 ^ 0.20 1993.65 ^ 0.40 0.772 ^ 0.070 0.181 ^ 0.050 50.1 ^ 8.0 175.7 ^ 4.0 82.2 ^ 4.0 [0.0064

TABLE 3 STELLAR DATA WDS Spectral Type (4) M0 V G5 K2 V K2 PRESENT WORK n(dyn) (arcsec) (5) 0.0332 0.0232 0.0211 0.0160 TABLE 4 EPHEMERIDES WDS 13320]3109 h (deg) ...... ...... ...... ...... ...... ...... ...... ...... ...... ...... 14.4 8.2 1.5 353.8 344.7 333.2 317.2 290.7 228.7 138.0 o (arcsec) 0.38 0.37 0.35 0.32 0.29 0.26 0.21 0.15 0.09 0.12 WDS 14310[0548 h (deg) 265.3 278.7 290.6 301.1 310.2 318.3 325.6 332.2 338.3 344.2 o (arcsec) 0.19 0.20 0.22 0.23 0.25 0.26 0.28 0.29 0.30 0.30 WDS 14492]1013 h (deg) 18.1 71.2 97.9 113.7 125.4 135.8 147.2 163.1 199.5 303.9 o (arcsec) 0.07 0.10 0.14 0.17 0.18 0.18 0.17 0.13 0.07 0.06 WDS 16384]3514 h (deg) 38.1 43.2 47.9 52.3 56.5 60.6 64.6 68.7 72.7 76.8 o (arcsec) 0.18 0.19 0.20 0.20 0.21 0.21 0.21 0.21 0.21 0.21 HIPPARCOS n(trig) (arcsec) (8) 0.03205 0.02604 0.02421 0.01149 ^ ^ ^ ^ 0.00296 0.00104 0.00129 0.00117

WDS (1) 13320 14310 14492 16384 ] [ ] ] 3109 0548 1013 3514 ...... ...... ...... ......

m A (2) 10.44 7.68 8.42 9.4

m B (3) 10.66 8.09 8.51 9.7

m A (6) 11.141 8.813 9.362 ...

m B (7) 11.367 8.390 9.272 ...

t 1999.0 2000.0 2001.0 2002.0 2003.0 2004.0 2005.0 2006.0 2007.0 2008.0


TABLE 5 OBSERVATIONS AND RESIDUALS ta WDS 13320]3108 1960.32 .......... 1961.39 .......... 1964.204 ........ 1964.362 ........ 1965.176 ........ 1966.335* ....... 1967.27* ........ 1968.30* ........ 1970.421* ....... 1971.32* ........ 1973.758 ........ 1975.29* ........ 1979.363 ........ 1980.30 .......... 1982.372 ........ 1984.3794 ....... 1987.2832* ...... 1987.3775* ...... 1988.2606* ...... 1989.2382* ...... 1989.30* ........ 1990.2082* ...... 1990.2704* ...... 1991.25 .......... 1991.3270* ...... 1996.40 .......... 1997.44 .......... 1997.3911 ....... WDS 14310[0548 1938.51 .......... 1943.61 .......... 1950.52* ........ 1951.61* ........ 1958.43* ........ 1959.35* ........ 1960.46* ........ 1961.43* ........ 1962.45* ........ 1963.37* ........ 1964.47* ........ 1965.57* ........ 1966.40* ........ 1968.32* ........ 1969.447* ....... 1976.22* ........ 1977.415 ........ 1978.35 .......... 1980.33 .......... 1983.176* ....... 1989.3090 ....... 1990.3437 ....... 1991.25* ........ 1992.4572 ....... 1995.46* ........ 1997.3939 ....... WDS 14492]1013 1916.40* ........ 1920.47 .......... 1923.45 .......... 1924.54 .......... 1926.36 .......... 1927.46 .......... : 352.8 355.9 263.8 ... ... 286.7 269.5 252.9 240.0 240.6 41.0 209.0 7.9 356.4 336.4 303.3 291.3 : 292.3 272.6 260.8 264.1 250.3 255.1 : 61 239.3 : 25.3 24.2 23.5 : 338.5 12.8 52.7 64.7 140.9 150.7 160.2 169.6 169.3 175.6 167.5 179.9 186.5 200.4 195.9 262.7 278.8 305.2 320.1 151.5 10.9 19.6 209 68.3 47.3 241.2 : 7.4 0.19 79.6 0.16 128.3 0.16 143.4 0.20 167.8 0.16 Too close 3 2 3 2 2 2 A A A A A A 18.9 [2.1 [0.4 3.2 [0.2 (224.4) 0.07 0.05 [0.02 0.02 0.04 (0.06) 0.39 0.37 0.25 0.25 0.26 0.28 0.29 0.30 0.30 0.29 0.34 0.28 0.23 0.24 0.28 0.19 0.19 0.19 0.22 0.27 0.255 0.219 0.187 0.102 0.22 0.177 2 2 3 1 9 3 9 2 16 3 4 13 7 1 1 3 1 3 3 3 ... ... ... ... 2 ... RST RST RST RST COU 3, B 6 COU COU 3, BAZ 5, B 1 COU B 4, COU 3, VBS 1, KNP 2, BAZ 6 COU COU 3, HLN 1 VBS 4, B 4, HLN 3, KNP 2 WOR 2, BAZ 5 COU BAZ HLN WAK HEI HEI WOR CHR CHR HIP CHR HEI BAG [2.7 [0.8 6.4 0.6 [0.5 2.9 5.3 8.9 2.7 3.7 [11.0 [5.7 [5.4 [13.8 [50.8 [5.4 [4.9 10.9 7.1 [1.8 [0.3 [1.2 [4.2 0.3 20.0 0.0 0.09 0.12 0.08 0.07 [0.01 0.00 0.00 0.00 0.00 [0.01 0.05 0.01 [0.02 0.07 0.18 [0.01 [0.02 [0.03 [0.03 [0.02 0.000 0.000 0.012 [0.002 0.06 [0.004 0.36 0.26 0.14 ... 0.12 0.16 0.24 0.19 0.38 0.27 0.36 0.25 0.30 0.23 0.24 0.181 0.187 : 0.148 0.224 0.263 0.19 0.304 0.277 : 0.33 0.337 : 0.32 0.32 0.403 4 4 3 1 1 3 3 3 3 3 3 3 4 3 6 . . . . . 2 . . . . 2 2 . WOR WOR WOR COU WOR WOR COU COU WOR COU WOR COU HEI 3, WOR 1 HEI WOR 3, HEI 3 MCA CHR BAG CHR CHR HEI BAG CHR HIP CHR HEI HEI BAG 5.0 [0.4 0.2 (252.7) (172.7) [3.2 [0.3 [3.1 2.6 9.2 4.1 0.4 3.3 [1.5 [2.3 [1.1 [6.0 [1.8 0.5 2.0 6.0 1.6 7.0 1.0 [0.1 [3.7 0.9 [0.1 0.06 [0.01 0.02 (0.11) 0.03 [0.01 0.01 [0.09 0.03 [0.10 [0.04 [0.15 [0.06 [0.11 [0.03 0.001 0.030 [0.015 0.005 [0.006 [0.08 [0.002 [0.031 [0.008 [0.003 [0.08 [0.08 0.007 h (deg) o (arcsec) Observer(s)b *h (deg) *o (arcsec)

n

. . . . . . . . .

. . . . . . . . .

..

2424


TABLE 5õContinued h (deg) o (arcsec) *h (deg) [4.1 4.1 [1.4 2.0 [11.6 [24.4 (309.4) 1.1 0.2 (41.5) [11.6 [8.1 0.8 0.9 34.8 [7.5 [2.5 46.5 [21.6 1.8 [2.4 6.5 5.1 1.6 6.9 [7.9 (104.2) 9.2 17.9 1.0 4.0 [0.5 2.3 [8.4 [0.9 28.9 [0.5 5.8 1.7 [1.1 [0.1 [0.8 1.7 1.6 [0.6 [1.3 1.0 [1.6 [2.3 3.4 11.7 [0.1 39.4 [1.6 1.3 [4.6 [22.7 [0.2 [7.0 [0.5 *o (arcsec) 0.05 [0.01 0.02 0.00 0.02 0.09 (0.06) [0.01 0.02 (0.08) 0.02 0.02 [0.04 [0.02 [0.06 0.03 0.03 0.03 0.01 0.01 0.01 [0.01 [0.02 [0.01 [0.05 0.05 (0.15) [0.015 [0.05 [0.006 [0.02 [0.001 0.006 0.008 0.002 0.06 0.005 0.007 0.000 0.002 0.000 [0.003 0.002 [0.03 [0.02 [0.02 0.02 0.00 0.01 [0.02 [0.04 [0.05 [0.079 [0.005 [0.003 0.005 0.035 0.003 0.03 [0.004

ta 1932.54 .......... 1933.52* ........ 1934.55* ........ 1935.43* ........ 1936.16* ........ 1936.98 .......... 1938.20 .......... 1943.94 .......... 1945.38 .......... 1949.47 .......... 1950.33* ........ 1951.57 .......... 1952.92* ........ 1954.14* ........ 1955.32 .......... 1957.28 .......... 1958.52* ........ 1958.58* ........ 1960.579* ....... 1961.43 .......... 1962.23 .......... 1963.364 ........ 1966.334 ........ 1972.42 .......... 1974.353 ........ 1975.44 .......... 1981.39 .......... 1984.1920 ....... 1984.44 .......... 1985.1862 ....... 1985.45 .......... 1985.5033 ....... 1986.4076 ....... 1987.3801 ....... 1989.2546* ...... 1989.48 .......... 1990.2746* ...... 1991.25 .......... 1991.3244* ...... 1992.3074* ...... 1993.1974* ...... 1995.4365* ...... 1997.394 ........ WDS 16384]3514 1973.43 .......... 1974.40 .......... 1976.33 .......... 1978.40 .......... 1980.47 .......... 1981.38 .......... 1983.477 ........ 1984.48 .......... 1985.41 .......... 1985.738 ........ 1989.8150 ....... 1990.4429 ....... 1990.514 ........ 1992.547 ........ 1995.4421* ...... 1996.415 ........ 1997.3915 .......

n 2 4 2 3 4 4 1 3 3 1 2 2 2 2 1 1 1 1 5 4 6 10 2 2 3 4 2 ... 2 ... 2 ... ... ... ... 5 ... ... ... ... ... ... ... 3 2 3 3 2 3 3 3 1 . . . 3 2 . 2 .

Observer(s)b FIN VBS 2, A 2 A A VOU B VOU VBS VBS 2, B 1 B VBS WRH VBS VBS VBS VBS B B VBS WOR B WOR 4, B 6 WOR COU HLN HEI HEI BNU HEI BAG HEI CHR BAG BAG CHR LBU CHR HIP CHR CHR CHR CHR BAG COU COU COU COU COU COU COU COU COU TOK BAG ISM COU COU CHR COU BAG

114.8 0.0.22 313.8 0.17 319.2 0.20 333.3 0.16 332.2 0.15 166 0.17 Too close 135.3 0.17 151.1 0.18 Too close 247.6 0.13 98.2 0.17 304.4 0.14 317.4 0.16 185.1 0.10 205.8 0.09 155.8 0.10 209.3 0.10 245.3 0.13 106.1 0.16 113.3 0.18 135.0 0.17 174.2 0.10 119.9 0.16 146.0 0.13 144.6 0.20 Round 146.8 0.167 158.2 0.13 150.2 0.157 156.9 0.13 153.2 0.151 174.5 0.117 220.2 0.065 212.5 0.077 75.5 0.14 259.3 0.112 108 0.155 285.1 0.145 296.2 0.173 307.1 0.182 332.1 0.151 234.0 0.059 : 47.9 50.1 57.5 68 73.8 76.9 91.7 104.7 97.6 138.8 124.6 133.4 128.2 140.8 189.9 13.7 27.9 0.17 0.18 0.19 0.23 0.21 0.21 0.18 0.15 0.14 0.104 0.138 0.130 0.137 0.118 0.116 0.17 0.156

.. .. ..

.. ..

a Asterisks mark observations that were subjected to a change of quadrant for calculation of the orbit. b WDS discoverer codes.

2425


2426

DOCOBO ET AL.
TABLE 6 STATISTICAL RESULTS rms(RESIDUALS) STAR Wor 24 ........ AUTHOR(S) Docobo & Balega ; this paper Heintz 1998 Baize 1991 Starikova 1985 Baize 1981 Baize 1976 Docobo & Tamazian ; this paper Soderhjelm 1999 Heintz 1981a I Heintz 1981a II Docobo 1977 I Docobo 1977 II Morel 1970 Couteau 1960 Balega & Vasyuk ; this paper Soderhjelm 1999 Eggen 1967 I Eggen 1967 II van den Bos 1964 van den Bos 1954 Ekenberg 1945 van den Bos 1945 Docobo & Ling ; this paper Baize 1993 *h (deg) 6.360 4.821 14.212 54.213 109.874 284.435 6.362 82.643 77.055 108.623 66.083 95.514 87.341 85.223 14.876 23.659 54.728 129.156 130.631 100.187 154.125 247.857 23.187 67.271 *o (arcsec) 0.047 0.100 0.162 0.207 0.250 1.304 0.031 0.077 0.383 0.457 0.442 0.414 0.267 0.448 0.823 0.825 0.773 0.770 0.738 0.789 0.765 0.737 0.048 0.078 MA(RESIDUALS) *h (deg) 1.680 1.422 2.762 9.253 17.020 63.862 2.301 10.752 10.849 16.153 10.148 15.587 15.337 17.617 3.628 4.895 10.222 18.614 20.762 17.472 31.175 54.081 4.795 14.104 *o (arcsec) 0.088 0.127 0.201 0.260 0.286 1.625 0.043 0.082 0.246 0.313 0.295 0.275 0.174 0.306 0.344 0.344 0.414 0.417 0.370 0.450 0.482 0.461 0.061 0.096

Vol. 119

RST 4529 ......

A 2983 .........

COU 985 ......

nitudes of the components, ]7.97 and ]8.19, agree better with the latter type and with the value of 0.2 given by Reid et al. (1995) for *m, the dierence in magnitude between the components. The calculated total mass is 1.35 M . WDS 14310ò0548, RST 4529 (Docobo &_Tamazian 1998). This binary was discovered by Rossiter (1938.51) with the 27 inch (0.69 m) telescope at the Lamont-Hussey Observatory. Prior to our calculations, orbits had been published by Couteau (1960), Morel (1970), Docobo (1977 ; two orbits, I and II), and Heintz (1981a ; two orbits, I and II). An orbit recently published by Soderhjelm (1999) exhibits signiïcant deviation of the position angle from both Rossiterîs measurements and the recent measurements of Balega et al. (1999 ; in the latter case by *h \[46¡2). . The components brightness similarity leads to the change of the quadrant in many observations. However, the possibility of a long period and low-eccentricity solution, as was calculated previously by other authors, is discarded because of an approximately 180¡ advance in h from 1992.4572 to 1997.3939. The Yale catalog (van Altena et al. 1995) lists an absolute trigonometric parallax of ]0A0108. UBV photometry has . been performed by Knipe (1966) and Alexander (1970). The calculated absolute magnitudes ]4.76 and ]5.17 and total mass 1.54 M indicate spectral type G5 V. _ WDS 14492+ 1013, A 2983 (Balega & Vasyuk 1998). This binary was discovered by Aitken in 1916.40 at the Lick Observatory. Prior to our work, orbits had been calculated by van den Bos (1945, 1954, 1964), Ekenberg (1945), and Eggen (1967 ; two orbits, I and II). The solution recently published by Soderhjelm (1999) exhibits excessive deviation of the position angle with respect to Balega et al. (1999)îs 1997.394 speckle measurement (*h \]15¡7). Radial veloc.

ity measurements have been published by Heintz (1981b) and in the Wilson-Evans-Batten catalog (WEB ; Duÿot, Figon, & Meyssonnier 1995). We did not consider the possibility of calculating another orbit of approximately 20 yr period and low eccentricity as was done by Eggen (1967) and Ekenberg (1945) since this provides worse residuals compared with those corresponding to the short-period orbit derived in the present paper. The Yale catalog (van Altena et al. 1995) lists an absolute trigonometric parallax of [0A0050. BV R photometric data . have been reported by Olsen (1993), Eggen (1955, 1965, 1971), and Wallerstain & Westfall (1960). The absolute magnitudes calculated from the Hipparcos photometric system, ]6.28 and ]6.19, agree better with the WDS spectral type, K2 V, than do those calculated from WDS apparent magnitudes, ]5.34 and ]5.43. The calculated total mass is 1.45 M . _ WDS 16384+ 3514, Cou 985 (Docobo & Ling 1998). Since its discovery by Couteau in 1973.43 with the 50 cm refractor at the Nice Observatory, this star has described almost one complete revolution. The only previous orbit (Baize 1993) deviates by about ]9¡ from the position angles obtained by the Center for High Angular Resolution Astronomy (1995.4421) and Balega et al. (1999 ; 1997.3915) speckle measurements. It is noteworthy that the measurements performed by Tokovinin in 1985.738 and Couteau in 1992.547 disagree with all others listed in Table 5. Hipparcos failed to provide separate data for the components of this binary. Moreover, in view of the WDS spectral type (K2), the absolute magnitudes and total mass calculated from the WDS apparent magnitudes and the Hipparcos trigonometric parallax, ]4.7 and ]5.0 and 5.30 M , respectively, imply that either the Hipparcos parallax is _


No. 5, 2000

ORBITS OF FOUR VISUAL BINARIES

2427

in error or at least one of the components lies o the main sequence. The authors would like to thank the referee, B. Mason, for useful comments and the US Naval Observatory for

data supplied from the Washington Double Star Catalog. This work was supported by the Xunta de Galicia (Spain) under project PGIDT-99-PX-124301B and by the Spanish 8 Direccion General de Ensenanza Superior e Investigaciona Cient·ïca under projects PB 97-0501 and PB 97-0514.

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