REED AREAS : A  CATALOGUE OF 1487 STARS IN PUPPIS, LISTING B1950 COORDINATES, MK SPECTRAL TYPES AND BV PHOTOMETRY.

1. INTRODUCTION.
Several years ago an extensive catalogue of BV photographic photometry and spectral classifications for 3339 stars was published, as part of a study of stars distribution in the Puppis low absorption window (Reed and Fitzgerald, 1984, hereafter referred to as RF). The particular field they studied has galactic coordinates (l,b) = (245, 0) and is accordingly designated MW 245. In terms of B1950 equatorial coordinates it extends from about 7h44m to 8h00m in R.A. and -26 to -28.5 in declination.

RF provided no coordinates for their catalogue of stars (referred to as Appendix A in their paper); the stars are identified on 17 finder charts (Appendix B), not published with their paper but held at the Royal Astronomical 
Society library, London.

This extensive catalogue has value for other types of research e.g. variable stars, and this writer decided that the data could be more readily utilized by other astronomers after equatorial coordinates had been determined for those stars with the best data, at least.

2. SELECTION OF STARS.
RF make it clear that the quality and completeness of data is not uniform for the 3339 stars of Appendix A. The stars with the best data i.e. complete two-dimensional spectral classifications, V magnitudes and B-V colours, total about 1500. It appears that the data (apart from positions) for the latter group have also been reproduced in 'MK Spectral Classificiations' (Buscombe 1988).

I have adopted Buscombe's selection of Appendix A stars, and this yielded 1487 stars for identification and coordinate measurement. For this purpose the complete set of 17 finder charts for the RF stars was obtained from the RAS library. Their scale proved to be a fairly generous one for measurement, at about 10.7"/mm.

3. REFERENCE STARS.
The main reference stars for coordinate measurement were taken from the SAO Catalogue. Occasionally stars from the Luminous Southern Stars Catalogue (Stephenson and Sanduleak 1971) were used to supplement the SAO stars; the precision is lower but still useful for checking purposes.

4. MEASUREMENT OF POSITIONS.
A ruled overlay grid was used to measure the positions of RF stars relative to the reference stars. The RF charts, as supplied by the RAS Library, were photostats of the originals. In addition to possible distortion introduced by the copying process some charts are mosaics, with adjoining portions sometimes not matching perfectly. Every effort was made to counteract these deficiencies in the chart material.

The final derived positions are far from ideal from an astrometrist's point of view. The precision of the position reflects the limitations of the material used and the simple method of measurement.
The probable error of the positions is expected to be
         Right Ascension  +/-  0.4s
         Declination      +/-  5"
Hopefully many positions will be better than this, and few will be worse. The purpose of this work is to provide positions which are sufficiently accurate for identification.

5. GENERAL.
RF subdivided MW 245 into 17 smaller fields, numbered B6, B7, C4..C7, D4..D7, E4, E6, E7, F4..F7. Stars are numbered serially within each field. I have retained their numbering system, but the order in which the fields are arranged in my catalogue differs. The most northerly band of fields (B7, C7..F7) appear first, followed by band B6..F6, and so on. Lastly, appear C4..F4.
The stars within each field are sorted in order of Right Ascension.

RF state that the probable error of their photographic V magnitude is +/-0.10m, and of a B magnitide +/-0.13m. As the original plates were scanned only once there is scope for refining the catalogue magnitudes if we wish to realize the accuracy achieved by photoelectric photometry.
The magnitudes in this catalogue should be regarded as preliminary. They may be frequently satisfactory for visual observers, but users should be alert to possible errors and discrepancies.

6. THE CATALOGUE.
The columns are as follows.

1.  Reed No. : Field number and star number by RF.
2.  Right Ascension for B1950.
3.  Declination for B1950.
4.  MK Spectral Type - a colon indicates uncertainty
                     - a closing bracket e.g. B8 V) flags greater uncertainty
5.  V magnitude (photographic)
6.  B-V index
7.  SAO number, when existing. Other ids. also inserted.

7. REFERENCES.
Buscombe, W. 1988. MK Spectral Classifications. Seventh General Catalogue.   
                   Northwestern University, Evanston.
Reed, B. Cameron and Fitzgerald, M.Pim 1984. Mon. Not. R. ast. Soc. 211, 243
Stephenson, C.B. and Sanduleak, N. 1971. "Luminous Stars in the Southern Milky
                   Way', Publ. Warner & Swasey Obs. 1,1 

M. Morel.  1990.
           2012 January 16