This “celestial diamond ring” is really the planetary nebula Abell 33.ESO
If you like planetary nebulae you may want to put a ring on this one. On second thoughts, it looks like this one’s taken; it already has a ring!
What looks like a gleaming diamond ring in the image above is actually the blown-off outer layers of a once-sunlike star, a spherical bubble of star stuff ionized by UV radiation coming from its super-dense corpse. The “diamond” at lower right is just a bright star serendipitously located between us and the glowing edge of the bubble.
Known to astronomers as Abell 33, this planetary nebula is located 2,500 light-years away in the southern constellation Hydra. The image was acquired with the European Southern Observatory’s VLT observatory, located atop the 2,600-meter-high Cerro Paranal in Chile’s Atacama desert.
What’s particularly uncommon about Abell 33 — besides its resemblance to human jewelry — is its spherical symmetry. Planetary nebulae (a misnomer coined by William Herschel because of their resemblance to planets in 18th-century telescopes) are usually more irregularly-shaped, or at least not so circular.