A recent image taken by the NASA-ESA Hubble Space Telescope captures a section of the dwarf spiral galaxy NGC 247, also known informally as the “Eye of the Needle.” It is located at a distance of 11 million light years from the Milky Way and is part of the Sculptor group. in the southern constellation of Cetus.
“The Eye of the Needle gets its nickname because one of its ends has a strange void of stars (not seen in this image),” the Hubble astronomers explained. “This image zooms in on the very edge of the galaxy, on the opposite side of the void.”
As the astronomers comment, “the bright red indicates areas of high-density gas and dust, and robust star formation quite close to the edge of NGC 247. The ‘hole’ in NGC 247 on the other side of the galaxy is a great mystery.”
“There is a shortage of gas in that part of the galaxy, which means there is not much material from which new stars can form. Since star formation has stopped in this area, old and faint stars populate the void. We still don’t know how this strange feature formed, but studies point to past gravitational interactions with another galaxy.”
The galaxy NGC 247 also hosts an ultrabright X-ray source . Astronomers have been arguing about its nature for a long time. According to one version, they are stellar-mass black holes that absorb an unusually large amount of gas. According to another version, it is a black hole of intermediate mass. Such objects are tens of times more massive than their stellar counterparts, but significantly smaller than the black holes found at the centers of most galaxies. Everything seems to indicate that it is a black hole of intermediate mass.
Reference: NASA / ESA / Hubble / H. Feng, Tsinghua University / G. Kober, NASA’s Goddard Space Flight Center / Catholic University of America.