The NASA/ESA Hubble Space Telescope has delivered an unrivalled snapshot of the irregular galaxy NGC 2814.
This Hubble image shows NGC 2814, an irregular galaxy some 85 million light-years away in the constellation of Ursa Major. Image credit: NASA / ESA / Hubble / C. Kilpatrick.
NGC 2814 is located approximately 85 million light-years away from Earth in the constellation of Ursa Major.
Otherwise known as IRAS 09170+6428, LEDA 26469 or UGC 4952, this galaxy was discovered by the German-British astronomer William Herschel on April 3, 1791
“NGC 2814 has three close galactic neighbors: a side-on spiral galaxy known as NGC 2820; an irregular galaxy named IC 2458; and a face-on non-barred spiral galaxy called NGC 2805,” Hubble astronomers said.
“Collectively, the four galaxies make up a galaxy group known as Holmberg 124.”
“In some literature these galaxies are referred to as a group of ‘late-type galaxies’,” they added.
“The terminology ‘late-type’ refers to spiral and irregular galaxies, whilst ‘early-type’ refers to elliptical galaxies.”
“This rather confusing terminology has led to a common misconception within the astronomy community.”
“It is still quite widely believed that Edwin Hubble inaccurately thought that elliptical galaxies were the evolutionary precursors to spiral and irregular galaxies, and that that is the reason why ellipticals are classed as ‘early-type’ and spirals and irregulars are classed as ‘late-type’.”
“This misconception is due to the Hubble ‘tuning fork’ of galactic classification, which visually shows galaxy types proceeding from elliptical to spiral, in a sequence that could easily be interpreted as a temporal evolution.”
“However, Hubble actually adopted the terms ‘early-type’ and ‘late-type’ from much older astronomical terminology for stellar classifications, and did not mean to state that ellipticals were literally evolutionary precursors to spiral and irregular galaxies.”
“In fact, he explicitly said in his 1927 paper that ‘the nomenclature … [early and late] … refers to position in the sequence, and temporal connotations are made at one’s peril’.”
“Despite Hubble himself being quite emphatic on this topic, the misunderstanding persists almost a hundred years later, and perhaps provides an instructive example of why it is helpful to classify things with easy-to-interpret terminology from the get-go!”
The new color image of NGC 2814 is made up of observations from Hubble’s Advanced Camera for Surveys (ACS) in the near-infrared and optical parts of the spectrum.
Two filters were used to sample various wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter.