II/185 PHOTOGRAPHIC UBV PHOTOMETRY STAR CATALOGUE OF THE OLD OPEN CLUSTER NGC 188 ================================================================================ FROLOV V.N.: 1990 Astron. Tsirk., 1544, 39 ================================================================================ Description: The UBV magnitudes for 2171 stars within an 80'x80'area centered on the old open cluster NGC188 were determined using plates taken with the Schmidt teles- cope of the Radio Astrophisical Observatory of the Latvian Academy of Sciences (80/120/240cm).Three plates for each colour (limiting magnitudes V=16.5) were measured with the help of the Pulkovo iris-photometer using the photoelectric standards of A.Sandage(1962) and O.Eggen, A.Sandage(1969). Characteristic curves were built separately for the bright (v<12.5) and faint (12.5-16.5) stars for the sake of improving the quality. The corrections to the magnitudes FOR colour equations were ignored because of their minority. Standard errors of the star magnitudes are: -------------------------------------------------------- | |sigma V | sigma B | sigma U -------------------------------------------------------- Inter.er.| faint st. | 0.03 | 0.04 | 0.05 | bright st.| 0.03 | 0.02 | 0.02 Exter.er.| faint st. | 0.07 | 0.06 | 0.08 | bright st.| 0.06 | 0.05 | 0.08 -------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- Intro 80 . This file catalog 96 2171 The catalogue -------------------------------------------------------------------------------- ================================================================================ Byte-per-byte Description of file: catalog -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- N Number of this catalogue 8- 14 A7 --- Sandage Sandage number 17- 22 F6.2 mm X Rectangular coordinate, with the origin at 0h 37m 51.843s +84d 57' 47.98" (1950.0) 24- 29 F6.2 mm Y Rectangular coordinate 32- 36 F5.2 mag Ve Photometric measurements (photoelectric) - 37- 41 F5.2 mag B-Ve Eggen and Sandage 43- 47 F5.2 mag (U-B)e 48 A1 --- u_(U-B)e Uncertainty flag (:) on U-Be 51- 55 F5.2 mag Vp Photometric measurements (photographic) by the author 56 A1 --- u_Vp Uncertaintly flag (:) on Vp 58- 62 F5.2 mag (B-V)p 63 A1 --- u_(B-V)p Uncertaintly flag (:) on (B-V)p 65- 69 F5.2 mag (U-B)p 70 A1 --- u_(U-B)p Uncertaintly flag (:) on (U-B)p 73- 76 I4 0.0001arcsec/a muX Relative proper motion, Upgren et al., 1972 79- 82 I4 0.0001arcsec/a mUY Relative proper motion, Upgren et al., 1972 85- 86 I2 % Pr Membership probability 89 A1 --- Member * if member of cluster (stars are situated along the cluster isochrone in the band +/-0.01 mag on the magnitude-colour diagram) 92 A1 --- C Contact (or crowned) stars 95- 96 A2 --- Notes 1) photographic photometry by McClure and Twarog (1977) 2) Double star (total photometry) 3) Double star (photometry of the bright component) 4) Variable star 5) Suspected to be variable star ------------------------------------------------------------------------------ The catalogue contains the following variable stars: 809 = ES CEP, 644 = V9, 843 = Y5, 1176 = V8 by Kaluzny and Shara(1986). ================================================================================ REFERENCES Sandage A.R. 1962: Astrophys.J,135,333 Eggen O.J., Sandage A.R. 1969: Astrophys.J.,158,669 Upgren A.R., Mesrobian W.S., Karridge S.J. 1972: Astronom.J.,77,74. McClure R.D., Twarog B.A. 1977: Astrophys.J.,214,111 Kaluzny J., Shara M. 1986: preprint Space Tel.Sc.Inst.,N139. ================================================================================ (End) Francois Ochsenbein [CDS] 23-Jun-1993