NGC 2775’s large, yellowish, central bulge is filled with old stars, encircled by tightly wound spiral arms decorated by dark dust and clusters of young, blue stars.
This Hubble image shows NGC 2775, a galaxy some 67 million light-years away in the constellation of Cancer. Image credit: NASA / ESA / Hubble / F. Belfiore / J. Lee / PHANGS-HST Team.
NGC 2775 is located approximately 67 million light-years away in the northern constellation of Cancer.
The galaxy was discovered on December 19, 1783 by the German-born British astronomer William Herschel.
It belongs to the Antilia-Hydra Cloud of galaxies and is the main member of a small group of galaxies called the NGC 2775 group.
Also known as Caldwell 48, LEDA 25861 or UGC 4820, NGC 2275 has a diameter of 80,000 light-years.
“NGC 2775 sports a smooth, featureless center that is devoid of gas, resembling an elliptical galaxy,” the Hubble astronomers said in a statement.
“It also has a dusty ring with patchy star clusters, like a spiral galaxy. Which is it, then: spiral or elliptical — or neither?”
“Because we can only view NGC 2775 from one angle, it’s difficult to say for sure.”
“Some researchers have classified NGC 2775 as a spiral galaxy because of its feathery ring of stars and dust, while others have classified it as a lenticular galaxy.”
“Lenticular galaxies have features common to both spiral and elliptical galaxies.”
“It’s not yet known exactly how lenticular galaxies come to be, and they might form in a variety of ways.”
“Lenticular galaxies might be spiral galaxies that have merged with other galaxies, or that have mostly run out of star-forming gas and lost their prominent spiral arms.”
“They also might have started out more similar to elliptical galaxies, then collected gas into a disk around them.”
According to the astronomers, NGC 2775 has likely merged with other galaxies in the past.
“Invisible in this Hubble image, NGC 2775 has a tail of hydrogen gas that stretches almost 100,000 light-years around the galaxy,” the researchers said.
“This faint tail could be the remnant of one or more galaxies that wandered too close to NGC 2775 before being stretched apart and absorbed.”
“If NGC 2775 merged with other galaxies in the past, it could explain the galaxy’s strange appearance today.”
“A Hubble image of NGC 2775 was previously released in 2020,” they said.
“The new version adds observations of a specific wavelength of red light that is emitted by clouds of hydrogen gas surrounding massive young stars.”
