COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 4020 Konkoly Observatory Budapest 5 May 1994 HU ISSN 0374 - 0676 POSITIONS OF VARIABLE STARS IN PLAUT'S FIELD 1 In the course of the Palomar-Groningen variable star survey, the late Prof. L. Plaut discovered several thousand variable stars in Baade windows. His record is the world- second by number of variables discovered by a single person, after C. Hoffmeister. Prof. Plaut's results were ultimately used for the well-known study of the spatial distribution of RR Lyrae stars in the central region of our Galaxy (Oort and Plaut, 1975). The majority of variables discovered by Plaut remain studied only by him. One of the reasons for this is that finding charts were not published for these stars. In the seventies, Prof. Plaut very courteously sent photographic charts of variable stars discovered by him to the compilers of the General Catalogue of Variable Stars. So we have a unique possibility to check positions and possible identifications of these stars and to provide the astronomical community with information necessary to find these objects in the sky. The present paper deals with the variable stars in the Palomar-Groningen Field 1 (Plaut, 1966). 77 variables were discovered in the field, 12 of them being rediscoveries. We have compared the finding charts for all of them with corresponding fields of the Hubble Space Telescope Guide Star Catalog. For this purpose, sky regions from the GSC catalog were visualized on a computer display. 30 stars have been identified with the GSC, the results are presented in Table 1. The columns of this Table are self-explanatory. Table 1 also contains GSC identifications for five GCVS stars discovered not by Plaut. These stars are indicated by an asterisk in the last column. Plaut's star No.32 (V771 Sco) appears double on Plaut's charts, we present co-ordinates for the brighter component. GSC co-ordinates for the star No.45 (V784 Sco) differ noticeably (by 0.5') from those given by Plaut. For those stars not present in the GSC, we have checked the agreement of their positions in the finding charts with co-ordinates published by Plaut or given in the GCVS. In most cases the agreement is very good. The position of No.57 (V797 Sco) in Plaut (1966) is wrong by 1d in declination, its correct co-ordinates must be 16h09m01s, -14d52.7' (1950.0); this agrees with the star's schematic position in Fig.4 in Plaut (1966). Other noticeable discrepancies have been found only in 3 cases presented in Table 2. The co-ordinates in this Table have been measured by us relative to neighboring GSC stars. The GCVS position for No.8 (EX Lib) was given according to Hanley (1942); our present position agrees better with Plaut (1966). The GCVS position for No.56 (V798 Sco) rests upon corrected co-ordinates communicated by Plaut to the compilers; the co-ordinates found by us differ considerably from the co-ordinates in Plaut (1966) and from the GCVS co- ordinates. Table 1 No. GCVS alpha_2000 delta_2000 GSC Plaut h m s d ' " 2 EU Lib 15 54 08.7 -10 50 36 5614-0851 GP Lib 15 54 29.2 -10 52 30 5614-0765 * 3 DT Lib 15 54 36.8 -11 11 28 5614-0609 5 DU Lib 15 55 14.0 -13 19 06 5622-1303 7 SW Lib 15 55 33.4 -12 51 04 5618-0788 12 FG Lib 15 56 58.7 -14 28 27 5622-1480 DW Lib 15 57 30.7 -14 04 50 5623-0863 * 14 FI Lib 15 57 42.8 -14 44 11 5623-0382 DX Lib 15 58 38.2 -13 40 25 5623-1017 * 16 FL Lib 15 58 40.4 -11 19 52 5619-1223 18 UV Lib 15 59 10.7 -14 10 55 5623-0576 24 FR Lib 16 00 15.9 -14 21 41 5623-0740 25 FS Lib 16 00 23.7 -12 20 58 5619-0068 26 FT Lib 16 00 52.1 -13 07 10 5619-0545 27 FU Lib 16 01 00.9 -09 26 36 5615-0235 28 V767 Sco 16 03 20.8 -10 30 11 5615-0464 29 V768 Sco 16 03 25.9 -13 19 31 5623-1134 31 V770 Sco 16 03 44.2 -13 06 49 5619-0373 32 V771 Sco 16 03 51.6 -13 10 32 5623-0577 33 V772 Sco 16 03 53.7 -12 27 54 5619-0172 40 V779 Sco 16 06 25.1 -14 34 40 5624-1376 44 V783 Sco 16 08 36.4 -12 06 28 5620-0573 45 V784 Sco 16 08 48.9 -14 38 45 5624-0978 49 V790 Sco 16 09 48.5 -14 37 16 5624-0608 54 V795 Sco 16 11 21.5 -13 55 49 5624-0343 58 V799 Sco 16 12 31.1 -14 42 03 5624-1026 60 V801 Sco 16 12 53.6 -12 09 44 5621-0363 V854 Sco 16 13 15.7 -09 53 24 5617-0730 * 61 V802 Sco 16 13 19.7 -13 31 36 5625-0196 65 V806 Sco 16 14 43.7 -10 42 53 5617-0524 KU Sco 16 15 01.3 -13 45 53 5625-0887 * 66 V559 Sco 16 15 04.0 -09 47 07 5617-0938 72 V812 Sco 16 15 57.9 -14 43 08 5625-0974 74 V814 Sco 16 16 19.1 -12 47 12 5621-0146 77 V817 Sco 16 18 13.2 -12 56 21 5621-0063 Table 2 No. GCVS alpha_2000 delta_2000 Plaut h m s d ' " 8 EX Lib 15 54 41.0 -12 47 34 56 V798 Sco 16 04 07.5 -12 59 30 48 V789 Sco 16 10 02.4 -12 18 01 We appeal to Dutch researchers having access to the material used by Prof. Plaut to check the problems raised in our publication. It is a pleasure to acknowledge the support of this study, which is a part of a general program of improving positions of variable stars, by the European Southern Observatory through grant No. A-02-047. We are grateful to Dr. V. Goranskij and Mr. A. Chicherov who developed the major part of the software we used. S. V. ANTIPIN Sternberg Astronomical Institute, 13, University Ave., Moscow 119899, Russia N. N. KIREEVA N. N. SAMUS Institute of Astronomy of Russian Acad. Sci., 48, Pyatnitskaya Str., Moscow 109017, Russia References: Hanley, G.M., 1942, Harvard Annals, 109, No. 3. [BIBCODE 1942AnHar.109...15H ] Oort, J. and Plaut, L., 1975, Astron. Astrophys., 41, 71. [BIBCODE 1975A&A....41...71O ] Plaut, L., 1966, Bull. Astron. Inst. Netherl., Suppl. Ser., 1, No. 3. [BIBCODE 1966BANS....1..105P ]