Feeling Blue: Hubble Spots ‘Lonely’ Dwarf Galaxy 100 Million Light-Years Away
The Hubble Space Telescope is back in action. After a short hiatus from science work, the spacecraft has been keeping busy by studying intriguing swaths of the sky.
Last week, the telescope imaged a strong-lensing galaxy cluster and found a smiling face hidden among the stars, as reported by the Inquisitr. This week, Hubble cast its inquisitive lenses over the constellation of Corona Australis (the “Southern Crown”) and encountered a very different sight that seems to mirror the complete opposite sentiment.
According to NASA, Hubble stumbled upon a “lonely” little galaxy known as ESO 338-4 — a blue dwarf galaxy floating 100 million light-years from Earth.
Imaged by Hubble’s Wide Field Camera 3 instrument — one of the two primary cameras on board the space telescope — ESO 338-4 is what astronomers describe as a blue compact dwarf galaxy. These small galaxies are made up of large clusters of young, massive stars that burn intensely in vivid shades of blue — making the entire galaxy don an azure apparel.
“Blue compact dwarf galaxies take their name from the intensely blue star-forming regions that are often found within their cores,” explained NASA officials. “One such region can be seen embedded in ESO 338-4, which is populated with bright, young stars voraciously consuming hydrogen.”
The image of ESO 338-4 was shared on Twitter by the Hubble team earlier today. As Sci-News points out, the color photo was created from different exposures captured by three Hubble instruments in visible, ultraviolet, and infrared light.
#HubbleFriday This captivating Hubble image shows a lonely dwarf galaxy 100 million light-years from Earth. The blue compact dwarf galaxy ESO 338-4 hosts intensely blue star-forming regions and can be found in the constellation Corona Australis: https://t.co/k0P8VbRaIK pic.twitter.com/HBYWileIbH
— Hubble (@NASAHubble) November 9, 2018
The blue stars which can be seen sparkling in the center of the snapshot were forged during a recent tempestuous event. Their birth is the result of a violent galactic merger that left a deep mark on the dwarf galaxy, disrupting the clouds of rich material around ESO 338-4.
Ignited by the turbulent encounter, the dust and gas clouds enshrouding the dwarf galaxy entered a frenzied star-forming state, churning out a new generation of stars at a rapid rate.
“These massive stars are doomed to a short existence, despite their vast supplies of hydrogen fuel. The nuclear reactions in the cores of these stars will burn through these supplies in only millions of years — a mere blink of an eye in astronomical terms.”
ESO 338-4 isn’t Hubble’s first encounter with a blue compact dwarf galaxy. In 2012, the telescope captured a dazzling photo of a blue dwarf called UGC 5497, a small galaxy tucked inside the Ursa Major constellation (the “Big Bear).
Located significantly closer to home, this dwarf galaxy lies just 12 million light-years from Earth, notes the Hubble Space Telescope webpage.
Three years ago, the space telescope caught a glimpse of another blue compact dwarf, found 45 million light-years from Earth in the Bootes constellation (the “Herdsman”). Dubbed PGC 51017, this blue dwarf is populated by a bizarre group of stars that are much older than previously believed. A photo of this dwarf galaxy is available on the Hubble Space Telescope website, along with some details on its puzzling nature.
