NGC 247 (also known as Caldwell 62) is an intermediate spiral galaxy located approximately 11.1 million light-years away in the constellation Cetus. It is a prominent member of the Sculptor Group, one of the closest galaxy clusters to our own Local Group. At a dec of -20, it’s as far south as I can image. I do this from my driveway here in the forest of western North Carolina.
The “Needle’s Eye” / “Claw” Galaxy: It has an unusual nickname. It’s called the “Needle’s Eye” because of an unusually large void or “hole” on one side of its spiral disk. This region contains older, redder stars. It lacks younger, bluer stars. This indicates that star formation there stopped about a billion years ago. Spanning about 70,000 light-years in diameter, it is smaller than the Milky Way and is viewed nearly edge-on from Earth.
Burbidge’s Chain: In deep images, a striking string of four distant background galaxies is visible. They are roughly 300 million light-years away. This string is located just to the north-east of NGC 247. These were a bonus I found in my image as I was processing it. I never saw them in the faint subframes. The difference between 11 million and 300 million light-years.
Astronomers speculate the galaxy’s distinctive void may have been caused by gravitational interaction with a “dark subhalo.” Another possibility is that another galaxy passed through its disk. While the void is quiet, the rest of the disk features bright pink H II regions. These are knots of glowing hydrogen gas where new stars are actively forming.
Astrobin version for acquisition details and annotated image.
