NGC 2974

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NGC 2974 is a lenticular galaxy in the constellation Sextans. It lies about 90 million light-years from Earth and spans roughly 90,000 light-years across. It was discovered by William Herschel on January 6, 1785. The galaxy is located a few degrees from bright stars and can be hard to see with small telescopes.

Although once described as elliptical, NGC 2974 has a disk and interesting internal structure. It hosts a rotating ring of neutral hydrogen and an outer ultraviolet ring with a small amount of young stars. The center shows two inner gaseous spiral features, which point to the presence of a bar about 540 parsecs across. There may also be a larger, outer bar.

The gas dynamics reveal that the HI rotation curve rises quickly, then declines to a flatter level, indicating a mass distribution that includes a significant dark matter component. The galaxy’s mass-to-light ratio increases with radius, and dark matter makes up at least about 55% of the total mass.

The nucleus is active, classified as a type 2 Seyfert galaxy, likely powered by material accreting onto a supermassive black hole estimated to be between 140 and 210 million solar masses.

NGC 2974 is the largest and brightest galaxy in its local group, which includes several companion galaxies. Its distance, structure, and active center make it a subject of ongoing study in galaxy evolution.