Over the coming weeks we will feature, in no particular order, each of the final 16 selected images and winners will be announced by Royal Museums Greenwich on 17 September. The winning images are to be showcased at the Royal Observatory Greenwich in an exhibition opening 18 September.
While truly massive stars go out in a blaze of glory, intermediate-mass stars — those between roughly one and eight times the mass of the Sun — are somewhat quieter. Such stars eventually form cosmic objects known as planetary nebulae, so named because of their vague resemblance to planets when seen through early, low-resolution telescopes.
This glorious image of the core of Local Group galaxy Messier 33 (NGC 598) in the constellation Triangulum was captured from Almere, Flevoland, Netherlands by astrophotographer Michael van Doorn — winning image of the Galaxies category in the Insight Astronomy Photographer of the Year competition 2015.
The December Geminid meteor shower is generally regarded as the richest and most reliable of the major annual shooting star displays. This year the predicted peak occurs close to 12h UT on 14 December, though high rates of activity should be encountered between 8pm GMT on Thursday, 13 December and 5pm GMT the following evening.