COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 3873 Konkoly Observatory Budapest 27 April 1993 HU ISSN 0374 - 0676 Identification of NSV Stars in the Hubble Space Telescope Guide Star Catalogue The Hubble Space Telescope Guide Star Catalogue (GSC) is a collection of approximately 20 million objects in the magnitude range 9 to 16 (see Lasker et al. 1990). Among other data, accurate coordinates (equinox J2000) are quoted for each star (see Taff et al. 1990 for a discussion on the positional errors of the GSC). This extensive database when combined with the excellent Pickles software package (McCarney, McArthur, and Jefferys 1989) is a powerful source for the identification and improvement of positions for different types of objects such as variable and suspected variable stars. In fact, the GSC has already been used in variable stars research by Gil Hutton (1992) and Morel (1992a,b) among others. In this note we report cross-identifications of southern suspected variable stars with GSC objects, as part of a program conducted to improve the positions of southern variable and suspected variable stars (see Lopez and Girard 1990, 1991). The suspected variable stars discussed here were extracted from the NSV catalogue provided in CD-ROM by the Astronomical Data Center and the National Space Science Center/World Data Center A for Rockets and Satellites (ADC/NSSDC). Stars which have both, the declination given to the nearest minute of arc and a literature reference to a finding chart, were isolated. The objects on one square degree around each of the NSV stars were plotted on the computer screen using Pickles (version 3.058). The suspected variables were then identified using the chart recommended in the NSV catalogue. Due to the fact that most of the coordinates quoted in the NSV are only approximate, this approach seems to be the most convenient for a correct identification of the star. No attempt has been made to do an automatic (computer) identification like the one being done by Egret et al. (1992) for the cross-identification of INCA with GSC objects. Table I lists the identifications which have been found. The first column gives the NSV number, the second one provides the GSC number with the TABLE I Identification of NSV with GSC Stars NSV GSC RA (1950.0) Dec h m s o ' " 03037 5948.00574 6 33 2.31 -15 20 21.0 03042 5073.01957 6 33 28.41 -13 2 29.8 03046 5952.01758 6 34 25.85 -16 56 59.9 03100 5953.02223 6 38 4.81 -17 47 24.5 03169 5957.00499 6 38 58.48 -20 6 9.8 03182 5953.01422 6 40 44.97 -17 17 15.9 03184 5949.01722 6 40 59.16 -15 53 9.2 03209 5957.01622 6 44 22.18 -19 16 0.2 03251 5391.01022 6 49 47.59 -13 26 15.5 03256 5958.01164 6 50 20.85 -19 3 31.0 03267 5958.02547 6 51 54.04 -19 26 4.8 03327 5963.00870 6 57 40.48 -15 51 33.4 03329 5967.00642 6 58 6.57 -18 32 36.3 03336 5971.00472 6 58 52.26 -18 47 16.6 03348 5963.01809 7 0 14.05 -15 34 55.1 03354 5963.01286 7 1 14.62 -15 28 6.9 03362 5967.00817 7 1 42.06 -17 48 17.4 03366 5972.02429 7 2 21.44 -19 33 11.8 03430 5964.03133 7 7 7.48 -16 15 37.5 03451 5964.03236 7 9 27.46 -16 7 24.9 03465 5406.02125 7 10 54.72 -13 13 23.5 03475 5973.00742 7 12 9.17 -19 35 7.7 03483 5969.01438 7 12 31.97 -17 24 34.8 03488 5906.01967 7 13 8.74 -14 21 37.3 03489 5965.02026 7 13 2.96 -16 10 54.1 03501 5965.00438 7 14 18.12 -15 36 49.2 03531 5969.00224 7 17 1.11 -17 52 52.8 03621 5983.00400 7 28 36.30 -16 54 25.5 03630 5983.01877 7 29 49.46 -18 16 27.6 03651 5979.02750 7 32 49.81 -15 1 24.7 03657 5987.00120 7 33 43.85 -18 38 20.4 03707 5418.02306 7 41 24.57 -11 47 6.1 03750 5985.00005 7 46 58.41 -17 35 46.6 03751 5423.00809 7 47 2.61 -13 39 38.5 03860 6562.02125 7 58 34.95 -26 48 27.9 03882 6558.02114 8 1 11.82 -25 21 35.6 03908 6007.01592 8 5 14.46 -21 41 2.3 03929 6004.01148 8 7 54.02 -20 9 34.2 03978 6009.00204 8 14 11.94 -21 9 56.4 03995 6560.02934 8 15 42.61 -25 51 25.2 04048 6009.03815 8 21 2.25 -20 49 3.8 04067 6573.04986 8 23 16.33 -25 55 13.7 05749 6109.00856 12 32 39.98 -20 17 13.5 08546 5657.00321 17 18 21.61 -13 27 10.8 12065 6306.02487 19 26 25.02 -19 22 2.4 12620 6313.01630 19 55 37.51 -15 14 28.0 12827 6319.01822 20 5 56.40 -18 24 44.5 12940 6315.00854 20 12 25.53 -15 45 38.7 14091 5806.00066 22 14 34.55 -11 44 41.7 format rrrrr.nnnnn where r refers to a region number and n to the order number on that region (see Lasker et al. 1990). The last two columns give RA and Dec (B1950.0). We have preferred to express the positions extracted from the GSC in the 1950 equinox -instead of the J2000 of the GSC- since it is the standard one for both the NSV and GCVS IV. No average between GSC positions of the same star in different regions has been made. I would like to thank the ADC/NSSDC for providing a CD-ROM with the NSV and GCVS IV among other very useful catalogues. Carlos E. Lopez Felix Aguilar and Yale Southern Obs. Benavidez 8175 (oeste) - 5413 Chimbas E-mail: celopez@unsjfa.edu.ar San Juan - ARGENTINA References: Egret, D., Didelon, P., McLean, B.J., et al. 1992. Astron. Astrophys. 258,217. [BIBCODE 1992A&A...258..217E ] Gil Hutton, R. 1992. Inf. Bull. Var. Stars No. 3723. Lasker, B., Sturch, C., McLean, B.J. et al. 1990. Astron. J. 99, 2019. [BIBCODE 1990AJ.....99.2019L ] Lopez, C.E., and Girard, T.M. 1990. Publ. Astron. Soc. of the Pacific 102,1018. [BIBCODE 1990PASP..102.1018L ] ------ 1991. Inf. Bull. Var. Stars No. 3681. McCarney, J., McArthur, B., and Jefferys, W.H. 1989. Bull. Amer. Astron. Soc. 21, 1075. [BIBCODE 1989BAAS...21.1075M ] Morel, M. 1992. Inf. Bull. Var. Stars No. 3701. ----- 1992. Inf. Bull. Var. Stars No. 3702. Taff, L.G., Lattanzi, M.G., Bucciarelli, B. et al. 1990. Ap J. (Letters), 353, L45. [BIBCODE 1990ApJ...353L..45T ]