The Milky Way Project First Data Release: a bubblier Galactic disc
We present a new catalogue of 5106 infrared bubbles created through visual classification via the online citizen science website ‘The Milky Way Project’. Bubbles in the new catalogue have been independently measured by at least five individuals, producing consensus parameters for their position, radius, thickness, eccentricity and position angle. Citizen scientists – volunteers recruited online and taking part in this research – have independently rediscovered the locations of at least 86 per cent of three widely used catalogues of bubbles and H ii regions  whilst finding an order of magnitude more objects. 29 per cent of the Milky Way Project catalogue bubbles lie on the rim of a larger bubble, or have smaller bubbles located within them, opening up the possibility of better statistical studies of triggered star formation. Also outlined is the creation of a ‘heat map’ of star formation activity in the Galactic plane. This online resource provides a crowd-sourced map of bubbles and arcs in the Milky Way, and will enable better statistical analysis of Galactic star formation sites.