3 Collaboration in observing
Observing and making measurements on your own can be fun, challenging and very rewarding – as we hope you are finding – but there are definite advantages in science to working collaboratively with others. As well as having access to more advanced equipment like COAST, working with others allows you to combine your results and find out much more than any one person working individually. In this section you will look at some collaborative projects involving The Open University (OU).
Earlier this week we looked at results on pulsating stars obtained from some of the largest and most advanced telescopes, such as the Hubble telescope. But smaller telescopes, such as COAST, are also perfect for studying such stars within our Galaxy, and even for more luminous examples in nearby external galaxies such as Andromeda. The reason for this is the development of very sensitive imaging detectors which, when coupled with even moderately sized telescopes, are ideal for obtaining very accurate measurements of a very large number of stars within the Galaxy. And this is precisely what is needed to determine the orbital or pulsational period of a star, or indeed to make observations of a very large number of variable stars to determine the regions of the HR diagram (or combinations of stellar temperature and luminosity) in which pulsating stars are to be found.
One particular example that the OU has been heavily involved with is a novel robotic telescope called SuperWASP (Wide Angle Search for Planets). Originally designed to detect the very small minute decrease in the light from a star as a planet orbiting it passes in front of it, this instrument consists of eight large aperture telephoto camera lenses backed with high-quality CCD detectors (Figure 10). This combination means that SuperWASP can map very large areas of the night sky in a single exposure – ideal for very large surveys of moderately bright stars.
The planet-finding survey with SuperWASP began in 2004 and as of 2016 had discovered 118 planetary systems. As well as looking for transiting exoplanets, SuperWASP has also identified large numbers of pulsating variables and eclipsing binary stars which have subsequently been followed up via dedicated observational programmes on other telescopes. This shows the real advantage that small, custom-designed, robotic telescopes have for these types of scientific investigations. Very large telescopes are best used when looking at very faint or distant targets, while smaller telescopes are much better suited to looking at bright targets, or many different objects at the same time in large surveys designed to identify variable stars.
Another example of collaboration is where researchers have access to data from space-based observatories and telescopes. In this video, OU astronomer Meredith Morrell explains how he makes use of data from the ESA satellite GAIA to plan and make follow-up observations using PIRATE, COAST’s companion telescope in Tenerife.
Finally, in this video Nayra Rodriguez Eugenio from the IAC (Instituto de Astrofísica de Canarias) describes some of the collaborative projects being carried out between Spain and the UK using COAST, including a search for variable stars very similar to the project that you will carry out.