Gemini South telescope captures spectacular end-of-life display of red giant star

The Gemini South telescope, one half of the International Gemini Observatory, has captured a rare sight - the death throes of an ancient red-giant star. This rarely seen bipolar reflection nebula, which looks like an old style of English jug, is believed to have formed by the interactions between the dying red giant and a now-shredded companion star.

IC 2220, nicknamed the Toby Jug Nebula, lies about 1200 light-years away in the direction of the constellation Carina (the keel). It is visible as a double-lobed cloud of gas and dust created and illuminated by the red-giant star at its centre.

At the heart of this reflection nebula lies its progenitor, a red-giant star named HR3126. 

For the unversed, red giants form when a star exhausts the hydrogen in its core. Without the outward force of fusion, the star begins to contract. Subsequently, the outer layers of the star expand by several hundred times compared to its original size, causing it to become a red giant. Our nearest star, the Sun, will also go through a similar evolutionary process and become a red giant in about five billion years from now.

In this case, the stellar material expelled from the red-giant star HR3126 flowed out into the surrounding area, forming a magnificent structure of gas and dust that reflects the light from the central star.

The formation of bipolar structures similar to those in the Toby Jug Nebula is commonly attributed to interactions between the central star and a binary companion star. However, in the case of HR3126, no such companion was found, instead, astronomers discovered an extremely compact disk of material around the central star. This suggests that the companion star was possibly shredded into the disk, which may have triggered the formation of the bipolar structure observed here.

"This end-of-life phase of red giant stars is relatively brief, and the celestial structures that form around them are rare, making the Toby Jug Nebula an excellent case study into stellar evolution," the NOIRLab wrote in a blog post.