Our research projects

Research is loosely organised into projects (established by project leaders, frequently with specific timeframes or goals) and programmes (established by programme coordinators, with ongoing goals and which may have related projects to investigate specific objectives).

Here’s the list of VSS research projects. Find a project that suits your interests, equipment and situation, and contact its project leader to find out about joining in.

Bright Southern Cepheids for DSLR & Similar Cameras

Project Leaders: Mark Blackford & Stan Walker

This project is the second stage of the Bright Cepheid project. It makes use of the advantages of standard DSLR cameras: wide fields and the ability to make measures in three colour bands simultaneously. It is limited by the camera’s sensitivity which appears to be about magnitude 8 with exposures of 20-30 seconds. But this still allows about 80 targets south of the equator. A list of all such objects can be found at Southern Cepheids to Magnitude 8. This is divided into several categories: low amplitude; long period (>10.0 days) which are mostly large amplitude objects with frequent period changes; and assorted Cepheids which are neither of these types. Previously many of these objects had been monitored by the ASAS project but this appears to have ceased around 2008 so that there is now no ongoing observational study of these stars. We plan to fill this need.


Dual-Maxima Miras

Project Leader: Stan Walker

The Mira stars are an interesting group of variable stars, well suited to visual observing. (And little observed in colours such as UBV) In most cases there is a quick rise to maximum brightness, followed by a slower decline to a rather faint level. The amplitudes are usually quite large, and the periods of 200-600 days make them easy to observe for the casual observer.

Amongst these stars there are a few unusual objects. These are Miras which, at times, show two distinct maxima minima. The most well-known of these stars in the 1960s were R Centauri and R Normae. Since then, two other southern objects have been observed – BH Crucis, discovered by Ron Welch in Auckland, and NSV 4721, now V415 Velorum, the existence of which was drawn to our attention by Peter Williams. The periods of these stars are all in excess of 400 days and usually 500 days. Colour photometry reveals another interesting feature, namely that the first maximum in R Centauri is bluer, hence hotter, than the second maximum, whereas the reverse is the case with BH Crucis.