The Pleiades

In this paper, we presented a revised Pleiades sequence (as a text file) which supercedes that given below. It is both an improvement for the INT-WFC and 2MASS systems, but also includes Johnson-Cousins data.

Bell et al (2012)

The aim of this paper is to create a benchmark test for pre-main-sequence isochrones using the Pleiades. The idea of the test is to use the models to produce a synthetic Pleiades photometric sequence which is then compared with the one we observed with the Wide-field Camera on the Isaac Newton Telescope.

To carry out the test one should first produce model fluxes for stars of masses which cover the appropriate mass range at an age of 130Myr. The fluxes should then be reddened by the equivalent of E(B-V)=0.04. The models then need to be folded through the system responses for the INT-WFC system which we give for U, g, r, i, Z. The zero point is defined in the standard way for SDSS, that a star of 3.631x10**-20 ergs/s/cm**2/Hz (3631 Jy) is of magnitude zero in all filters. Finally the sequence should be placed at a distance corresponding to a distance modulus of 5.63. The resulting sequence can be compared with either the photometry for our Pleiades members in cluster format or in FITS format, or our estimate of the single star Pleiades sequence in the natural INT-WFC and 2MASS systems as a text file.

As a result of this work we have also defined a set of theoretical transformations from the SDSS system to the natural INT-WFC system which we give as a text file. We have applied these transformations to a subset of the SDSS Stripe 82 photometry to define a set of standard stars in the INT-WFC system which we give in both cluster and FITS formats. In case further Pleiades members are discovered in our field-of-view we also give our full photometric catalogue again in both cluster and FITS formats.

We updated Tables 2, 4 and 5 in October 2012. In all cases we changed the labels U and Z to capitals so they are consistent with the paper. In addition the Table 5 we originally supplied was not the version where the variability flags had been removed and the magnitudes for the stars so flagged replaced by averages from a single night. The new Table is the one where this has been done, but also originates from a re-reduction of the data, and so we have also replaced Table 2 to retain consistency. This is also the version of the data which appear as online material with the paper, but I believe the CDS version is the earlier one.