Free Astronomy Magazine May-June 2022

15 MAY-JUNE 2022 ASTRO PUBLISHING H istorical records do show that about 170 years ago Eta Cari- nae underwent an unusual outburst that made it one of the brightest stars in the southern sky. That explosion generated a structure of dust and gas known as the Homunculus Nebula. [NASA, ESA, Hubble; Processing & License: Judy Schmidt] A new astronomical visualiza- tion from NASA’s Universe of Learning showcases the multiwavelength emissions (from infrared light through X-rays) and three-dimensional structures sur- rounding Eta Carinae, one of the most massive and eruptive stars in our galaxy. The video, “Eta Carinae: The Great Eruption of a Massive Star,” has been released on hubblesite.org and universe-of-learning.org . Eta Carinae, or Eta Car, is famous for a brilliant and unusual outburst, called the “Great Eruption,” ob- served in the 1840s. This briefly made it one of the brightest stars in the night sky, releasing almost as much visible light as a supernova ex- plosion. The star survived the out- burst, and slowly faded away for the next five decades. The primary cause of this brightness change is a small nebula of gas and dust, called the Homunculus Nebula, that was expelled during the blast, and has blocked the light of the star. Observations using NASA’s Hubble Space Telescope and Chandra X-ray Observatory reveal the details in vis- ible, ultraviolet, and X-ray light. As- tronomers and artists at the Space Telescope Science Institute (STScI) in Baltimore, Maryland have devel- oped three-dimensional models to represent the hourglass shape of the Homunculus and the clouds of glowing gas that encompass it. The result is a stunning tour of the nested emissions that brings the 2D images to 3D life. “The team did such an amazing job representing the volumetric layers that viewers can immediately and intuitively comprehend the complex structure around Eta Car,” said Frank Summers, principal visualiza- tion scientist at STScI and project lead. “We can not only tell the story of the Great Eruption, but also show- case the resulting nebula in 3D.”