European Southern Observatory, Karl-Schwartzschild-Strasse 2, 85748 Garching, Germany e-mail: email@example.com,firstname.lastname@example.org
2 Department of Astronomy, P. Universidad Católica, Casilla 306, Santiago 22, Chile e-mail: email@example.com
Corresponding author: M. Rejkuba, firstname.lastname@example.org
Accepted: 6 May 2003
The first variable star catalogue in a giant elliptical galaxy NGC 5128 (Centaurus A) is presented. Using multi-epoch observations with ISAAC at the VLT we have detected 1504 red variables in two halo fields covering 10.46 arcmin square. For the variables with at least 10 good measurements, periods and amplitudes were determined using Fourier analysis and non-linear sine-curve fitting algorithms. The final catalogue contains 1146 long period variables with well established light curve parameters. Periods, amplitudes, photometry as well as individual Ks-band magnitudes are provided for all the variables. The distribution of amplitudes ranges from 0.3 to a few magnitudes in the Ks-band, with a median value around 0.7 mag. The amplitudes, mean magnitudes and periods indicate that the majority of variables belong to the class of long period variables with semiregular and Mira variables. Exhaustive simulations were performed in order to assess the completeness of our catalogue and the accuracy of the derived periods.
Key words: galaxies: elliptical and lenticular, cD / galaxies: stellar content / stars: variables: general / stars: AGB and post-AGB / galaxies: individual: NGC 5128
Based on observations collected at the European Southern Observatory, Paranal, Chile, within the Observing Programmes 63.N-0229, 65.N-0164, 67.B-0503, 68.B-0129 and 69.B-0292, and at La Silla Observatory, Chile, within the Observing Programme 64.N-0176(B).
© ESO, 2003