Double Stars

Project Leader: Neil Webster
Members: Simon Dawes

The Washington Double Star catalogue, Webb Deep Sky society, The American Astronomical League, The BAA all have lists of neglected doubles requiring measurements from amateurs. More measurements mean possible future orbit calculations. The downside is that they are neglected for a reason (very tight separations with large magnitude differences between the components!!).........................but it could be a challenge.

There's so much more to these objects than two stars orbiting a common centre of mass. In fact, there are rarely just two... Spectroscopic analysis often reveals very close stars orbiting the main visual stars. And again and again a third member is found, so we really are talking multiple star systems. And just how/why do these systems form from the original collapsing gas cloud and initial open star cluster. Studies of open cluster members usually reveal double star systems within.

Historically, they are important as they were the first method of ascertaining stellar masses (using good old Kepler's 3 laws), but they seem to have fallen out of favour with astronomers, although they can be observed in bad light-polluted areas (as I know!!), and there are so many within range of small telescopes (comfortable separations and comparable magnitudes/colours between components). And, forgetting the science, they can be very beautiful!!

An introduction to Double Stars (history, measurements...etc)
CMHASD - DoubleStars