Lucke catalogue of stars in LMC associations

This is to announce another large catalogue of stars likely to be useful as regards variables, this time in the LMC. About 10 years ago Australian variable-star chart-maker Mati Morel went over charts in an unpublished 1972 PhD thesis by Peter Lucke (loo-key) to determine accurate coordinates and IDs. The ~5000 stars involved are identified only on the charts. Mati completed the task (tedious in the extreme) of finding each star on images and catalogues using copies of the source charts in the thesis, which are reverted to the sky. The thesis data remain valuable since the related journal papers have over 600 citations in ADS (unusual for work over 50 years old). The thesis is not scanned or available on-line.

I have gone over Mati’s file to get improved positions from GAIA3 and other higher-resolution catalogues. In the process I was able to get spectral classification estimates for around half the stars from GAIA3 spectra. Mati did an amazing job of picking out the stars in the dense fields. The only errors I found were due to the limited resolution of the catalogues he had access to, or because the Lucke charts were ambiguous. To help with the latter I ended up borrowing the Univ of Washington (Seattle) copy of Lucke’s thesis, where the work was done, via interlibrary loan (thanks to wonderful Lowell Observatory librarian/archivist Lauren Amundson).

I ended up stripping out the various photometric lists that Mati compiled, and show only Lucke’s photographic photometry in order to provide a machine-readable record of the thesis work itself. The Lucke V magnitudes are remarkably good, without obvious scale error, though noisy at the faint end (V mag 15 to 16). The B-V colors are poor, however, especially for very blue stars, where they become much too blue (colors bluer than an infinitely-hot blackbody!). Many of the associations have CCD photometry, but even now coverage is incomplete.

The plain-text file is copied to the Lowell ftp area (about 390Kb):

https://ftp.lowell.edu/pub/bas/starcats/LH-morel.dat

…which has a lot of detailed notes about many of the stars.

\Brian

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