COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 1668 Konkoly Observatory Budapest 1979 September 5 A SEARCH FOR V567 SCORPII Introduction The Cepheid V567 Sco=HV 10793 was discovered by Henrietta Swope (1943). Unfortunately the published identification chart for this variable, which is located in a very crowded field, is of such small scale that positive identification proved to be impossible. In order to recover this object we therefore obtained photoelectric UBV photometry of a number of field stars located near the quoted position of the variable. Observations Observations of 13 non-variable stars situated near V567 Sco are listed in Table I. The stars in this table are identified in Fig. 1. Table I Observations of field stars -------------------------------------------- Star V B-V U-B -------------------------------------------- 1 10.42 0.14 -0.56 2 11.36 0.41 0.25 3 12.10 0.41 0.30 4 12.17 0.98 0.62 5 14.56 0.51 0.44 6 12.34 0.28 -0.05 7 13.38 0.48 0.37 8 12.72 1.29 1.06 9 14.84 0.75 0.21 10 12.17 0.99 0.61 11 13.90 0.52 0.41 12 13.58 0.57 0.33 13 13.01 1.59 1.80 -------------------------------------------- The observations were carried out with the 1.5-m and 0.9-m telescopes of the Cerro Tololo observatory in 1978 (stars 1-9) and 1979 (stars 10-13). Star 10, which was originally thought to be the variable, was observed 4 times. All other stars were observed only once. [FIGURE 1] Fig. 1. Identification chart for V567 Sco and comparison stars. The chart, prepared from a 103aO+GG385 plate obtained with the Curtis Schmidt has dimensions of 9.8x12.2 arc min. Observations of the variable itself are given in Table II. Table II Observations of V567 Sco Date U.T. V B-V U-B Tel. 1979 Mar.21 08:40 12.21 2.17 2.21 1.5-m Mar.23 07:55 12.42 2.18 2.32 1.5-m Mar.31 08:17 13.31 2.13 - 0.9-m Discussion A color-magnitude and a color-color plot for the stars in Table I are shown in Figs. 2 and 3, respectively. Eight of the thirteen observed stars lie on, or close to, the loci that would be expected for a poor star cluster or association with (m-M)_0= 10.0 +- 0.3 (m.e.) and E_B-V = 0.37. Alternatively all of the field stars with B-V <0.6 might be unrelated objects with 9.0<~(m-M)_0<~11.0 that are located behind a single absorbing cloud. Unfortunately the three observations listed in Table II do not strongly constrain and for the Cepheid. Adopting [FIGURE 2] Fig. 2. Color-magnitude diagram for field stars. Possible cluster members are shown as triangles. [FIGURE 3] Fig. 3. Color-color plot for field stars (circles) and possible cluster members (triangles). Also shown is the intrinsic color-color relation and the color-color relation for E_B-V=0.37. ~ 12.5, - - ~2.15, M= -5.62 and ( - )_0 = 1.00, which are the values derived from van den Bergh's (1977) calibrations of the period-luminosity and period-color relations for a Cepheid with P = 34.04 days, yields A_V ~ 3.8 and (m-M)_0 ~14.3. These values place V567 Sco well beyond the possible clustering of field stars discussed above. One of us (SvdB) wishes to acknowledge the kind hospitality of the Cerro Tololo Observatory. SIDNEY VAN DEN BERGH* and FRANK YOUNGER Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics References: Swope, H.H. 1943 Harvard Ann. 109, No. 9 [BIBCODE 1942AnHar.109...31S ] van den Bergh, S. 1977 in Redshift and Expansion of the Universe eds. C. Balkowski and B.E. Westerlund (Paris-CNRS) p. 14 [BIBCODE 1977dreu.coll...13V ] * Visiting astronomer Cerro Tololo Inter-American Observatory. CTIO is supported by the National Science Foundation of the USA under contract NSF C866.