COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 3702 Konkoly Observatory Budapest 11 March 1992 HU ISSN 0374 - 0676 IDENTIFICATIONS AND COORDINATES FOR NINETEEN NSV STARS The New Catalogue of Suspected Variable Stars (Kholopov et al. 1982) contains a number of neglected stars which have been known for many decades. It is clear that for some NSV stars further study is hampered by the scanty nature of the published data, i.e. coordinates of low accuracy; magnitude ranges which may refer to an obsolete magnitude scale; finder charts which are non-existent. An example of a set of variables which illustrates the above difficulties is the set of twenty-six new variables announced by Voute (1927). Five of these have received official names (MW Cen, TV Hya, RZ Nor, TU Nor, and probably LQ Nor reported in this present work). Two other stars, NSV 5596 and NSV 7789, were known at discovery to be CPD stars. We are left with nineteen variables whose identities are still somewhat obscure - the published coordinates are only approximate, no finder charts exist, and no magnitudes are available at all for many of them. The purpose of this paper is to establish secure identifications for the nineteen poorly known variables. The remainder of Voute's stars, mentioned above, are better known and will not be discussed further. I have used Voute's original discovery paper to determine the position of each variable with greater accuracy. He gave brief descriptive notes for each star, regarding its apparent behaviour and position relative to nearby CPD stars. These offset positions usually (but not always) enabled me to pin down the location of each variable with higher degree of confidence. Small finder charts were plotted for each object using stars extracted from the Guide Star Catalogue (GSC). The limiting magnitude of the GSC charts is generally around 13.5(J) which is very similar to the limit of the original plates used to discover the variables (Voute 1927). An inspection of each GSC chart generally revealed a suitable candidate. For a few of Voute's stars no obvious candidate could be found in the GSC, so Robert H. McNaught (Siding Spring Observatory) kindly agreed to search UK Schmidt plates for possible candidates. The results of the research are summarized in Table 1. Additional notes appear below for a small number of stars difficult to identify. NSV 4897: Has two fainter companions. The first one, of about magnitude 13.0, lies 6s preceding, 17" N. The other is of magnitude 13.5 and lies 54" N; it is known as GSC 8609-1976. NSV 5060: The probable candidate is an anonymous star of about magnitude 14, located 1.0' N of the position given by Voute. No star seen at his position on UK Schmidt plate J2237, 1976 April 22. No variable or coloured star in vicinity, according to McNaught (1991). [FIGURE 1] Fig. 1. Finder charts for the NSV stars. North is up, and East is left for each chart. Scale bar in each chart gives the scale in arc minutes. NSV 7679: Identity a little unclear. UK Schmidt plates show an anonymous red star very close to the position stated by Voute, but it is rather faint and probably too faint for his plates. No variability found by McNaught (1991). Voute suggested that his variable is of Algol type, of period 11 days or a submultiple of it, and amplitude 0.6 mag. The nearby star GSC 8320-2049 is the more likely candidate, as it is not particularly coloured (by comparing UK Schmidt J and I plates) and is within the limit of the discovery plates. [FIGURE 2] Fig. 1. (contd.) Finder charts for the NSV stars. North is up, and East is left for each chart. Scale bar in each chart gives the scale in arc minutes. NSV 7724: Identity a little unclear. Candidate listed in Table 1 is the brightest star in the immediate vicinity of Voute's coordinates. other, fainter stars lie closer to his position. No variable or coloured star in vicinity, according to McNaught (1991). Table 1: IDENTIFICATIONS AND COORDINATES FOR NINETEEN NSV STARS NSV GSC R.A. (2000) DEC. Voute ident. No. GSC No. Mag(J) h m s d ' " (1875 position) Remarks ------------------------------------------------------------------------------ 4889 6209-266 12.52 10 32 43.9 -50 46 52 10 27.6-50 8 4890 8956-2001 11.55 10 32 49.8 -60 27 52 10 28.2-59 50 4894 8613-2569 12.99 10 33 45.5 -59 37 33 10 29.1-58 59 4897 8609-2859 12.04 10 34 14.9 -56 45 59 10 29.3-56 7 Two companions 4921 8209-1199 12.52 10 38 51.5 -52 04 13 10 33.7-51 25 5060 --------- (14) 11 01 30.0 -53 34 45 10 56.1-52 56 Best candidate 5069 8627-898 11.99 11 02 42.5 -59 36 36 10 57.5-58 56 7609 8711-3885 12.62 16 19 43.2 -53 44 38 16 10.0-53 28 7640 8719-1115 10.99 16 22 12.3 -57 40 23 16 11.9-57 22 7648 8719-1381 11.26 16 22 32.5 -57 43 56 16 12.2-57 26 Misprinted as 16 22.2 7679 --------- <14 16 24 22.1 -50 26 17 ------------- Doubtful. Red 7679 8320-2049 12.60 16 24 18.3 -50 25 33 16 14.9-50 9 Good candidate. White. 7699 8719-818 13.48 16 26 32.9 -57 01 47 16 16.2-56 44 7724 --------- (13.5V) 16 28 08.0 -55 38 16 16 18.1-55 20 Best candidate 7760 8712-348 11.88 16 30 58.0 -52 49 49 16 21.2-52 33 7767 8720-116 12.72 16 31 39.7 -57 40 55 16 21.2-57 24 7774 8720-1256 13.37 16 31 59.8 -58 07 17 16 21.6-57 52 LQ Nor 8716-295 12.25 16 33 39.4 -56 12 29 16 23.6-55 56\Same 1875 coords. 7804 8716-317 12.71 16 33 57.8 -56 12 31 16 23.6-55 56/given by Voute 7832 8712-2444 11.98 16 35 55.5 -53 16 27 16 26.1-53 0 9865 7386-1741 11.56 17 56 46.3 -35 14 52 17 48.4-35 13 =CoD-35 12083 =CPD-35 7524 ------------------------------------------------------------------------------ Table 1: The data found for each NSV star is given here. The columns are as follows : Column 1: Star number in the NSV Catalogue. " 2: Star number in Guide Star Catalogue (GSC). " 3: Magnitude from GSC (from UK Schmidt J plates). " 4: Coordinates (J2000) from GSC. " 5: The identifier used by Voute (1927). He did not assign temporary designations, but instead referred to each star by its approximate 1875 coordinates. " 6: Remarks. Charts: Fig. 1 gives finder charts for all variables. The scale of each chart is indicated, together with the CPD star used for offsetting by Voute. I wish to thank Mr Albert F. Jones of Stoke, Nelson, New Zealand, and Mr Robert H. McNaught of Siding Spring Observatory, NSW, for providing material and observations used in the preparation of this paper. MATI MOREL 18 Elizabeth Cook Drive Rankin Park NSW 2287 Australia REFERENCES: Guide Star Catalogue : 1989, Space Telescope Science Institute, Baltimore, Maryland, USA. Kholopov, P. N. (ed.): 1982, New Catalogue of Suspected Variable Stars, Nauka, Moscow. [BIBCODE 1982ncss.book.....K ] McNaught, R. H.: 1991, Private Communication. Voute, J.: 1927, BAN 4, 16-17 [BIBCODE 1927BAN.....4...16V ] [DATAFILE 1]