A cosmic diamond ring is the best way to describe the haunting beauty of a distant star in its final moments of life.
Located some 2,500 light-years from Earth within the belly of a mythical water snake, Abell 33 (also known as PK238+34.1) represents the final remains of a sunlike star that has thrown its atmosphere into space, releasing a vast bubble of gas and dust called a planetary nebula.
This stellar remnant is captured in striking detail never seen before, thanks to the Very Large Telescope in the high desert of Chile.
The chance alignment of the nebula and a brilliant, sparkling star together create the mesmerizing diamond-ring effect.
Look carefully to see, just off-center in the image, the tiny, Earth-size core of the nebula’s progenitor star. It still burns with enough energy to bellow copious amounts of ultraviolet radiation into surrounding space, which will make the bubble glow for tens of thousands of years before fading into darkness.
See for Yourself
Abell 33 belongs to a celestial catalog of 86 planetary nebulae put together by astronomer George Abell back in 1966. It is located inside the southern constellation of Hydra, the Water Serpent.
To catch a glimpse of the 12th-magnitude ghost bubble, you will require a medium-size backyard telescope with an 8- to 12-inch mirror and dark skies. Start your hunt in the southeastern skies and locate the faint (but visible to the naked eye) star Iota Hydrae, which represents the neck of the serpent constellation. This will act as the stellar guidepost to find the tiny cosmic bubble.
Some landmarks in the sky on April 10 include the gibbous moon, which will appear wedged between the bright star Regulus in the constellation Leo, above Iota Hydrae. The much fainter orange-hued snake star will appear below the moon. The glare of the moon will wash out many faint stars, so use binoculars to pinpoint Iota Hydrae.
Now that you know where Iota Hydrae is located, on an upcoming moonless night use a low-power eyepiece to scan 1.5 degrees (the width of three full moons) below the star to see Abell 33. Using high magnification—around 150x—will reveal the nebula as a very tiny, faint, gray disk.
While backyard instruments won’t produce a spectacular sight the way a giant observatory will, it is still awe-inspiring to witness the death of a distant cousin of our sun.