
Messier 57 is the famous Ring Nebula in Lyra, a showpiece planetary nebula that’s arguably the finest and most observed in its class. A measure of its popularity is the ease in which it can be located, lying roughly midway between third-magnitude Sheliak and Sulafat (beta [β] and gamma [γ] Lyrae), but once you land on the Ring it offers the startling sight of a celestial ‘smoke ring’, through even a small telescope. M57 also affords observers an advantageous high surface brightness that’s ideal to punch through early summer’s twilight-infested night-time.

How to observe
The constellation Lyra rides high on mid-summer evenings, led by blazing Vega, which, at a glorious magnitude +0.03, is the fifth-brightest star in the entire sky. By 11pm BST at around mid-month from the south of England, what passes for darkness at this time of the year has fallen and Vega already sits over 70 degrees clear of the south-south-eastern horizon. The aforementioned Sheliak and Sulafat lie around six to seven degrees south-east of Vega.
Upgrading to a 100mm (four-inch) telescope and increasing the power to say 100×intensifies the Ring’s elliptical shape and can reveal some brightness variations in an otherwise evenly illuminated disc. The addition of an O-III filter is highly recommended on a night of steady seeing to try to eke out more of the Ring’s subtle structure. Most observers see the Ring as merely grey-white.
If you want to see M57’s central star, the white dwarf remnant, then you’ll need at least a 400–500mm (16- to 20-inch) aperture operating under a very dark and transparent sky. It might be better to wait until August for the return of darker skies. It is clearly seen in amateur images. The star has a temperature of about 150,000 degrees, a mass 1.2 times that of the Sun and a luminosity 500 times greater than that of our star, with most of that at ultraviolet wavelengths.
