NGC 247 (also known as Caldwell 62 and commonly known as the Claw Galaxy[2]) is an intermediate spiral galaxy about 11.1 Mly away in the constellationCetus. This distance was confirmed in late February 2011. Previous measurements showed that the galaxy was about 12.2Mly away, but this was proved to be wrong.[3] NGC 247 is a member of the Sculptor Group, and is 70 000 light years in diameter. [4]
NGC 247 has an unusually large void on one side of its spiral disk. This void contains some older, redder stars but no younger, bluer stars.[5]
Nearby galaxies and galaxy group information
NGC 247 is one of several galaxies that is gravitationally bound to the Sculptor Galaxy (NGC 253). These galaxies form a small core in the center of the Sculptor Group, which is one of the nearest groups of galaxies to the Milky Way.[6] Most other galaxies associated with the Sculptor Group are only weakly gravitationally bound to this core.[6][7]
Burbidge's Chain
In 1963, Geoffrey Burbidge and Margaret Burbidge identified a group of five background galaxies located northeast of NGC247.[8] This grouping came to be known as Burbidge's Chain, and in 1977 it was listed in the VV catalog as VV518.[9] Individually, the 5 galaxies are also identified as NGC247A, NGC247B, NGC247C, NGC247D, and ESO540-025.
^Burbidge, E. M.; Burbidge, G. R.; Hoyle, F. (1963). "Condensations in the Intergalactic Medium". The Astrophysical Journal. 138: 873. Bibcode:1963ApJ...138..873B. doi:10.1086/147692.
^Vorontsov-Velyaminov, B. A. (1977). "Atlas of interacting galaxies, Part II and the concept of fragmentation of galaxies". Astronomy and Astrophysics Supplement Series. 28: 1. Bibcode:1977A&AS...28....1V.