This paper describes the observations and gives the results of a series of observations of bright E-region stars for use as zero point stars for DDO photometry in the southern hemisphere. The list comprises 45 stars, all brighter than V = 6.0, and gives the colours in the instrumental system with internal s.e. ±0.001 mag and m48 with s.e. ±0.002 mag. The observed m48 is indistinguishable from McClure's system and has the same zero point (±0.002 mag). The individual E-region zero points have been established with s.e. ±0.001 relative to the instrumental system, but the colour equations (and zero point corrections) to transform the instrumental colours to McClure's system have still to be finalised.
South African Astronomical Observatory Circular
- Pub Date:
- DDO Photometry: Stars