instrument at the
Very Large Telescope. observations of the outflows. . (Credit: HST/
NASA/
ESA). The Sculptor Galaxy is located at the center of the
Sculptor Group, one of the nearest
groups of galaxies to the
Milky Way. It is the brightest galaxy in the group and one of the
intrinsically brightest galaxies in our vicinity, only surpassed by the Andromeda Galaxy and the
Sombrero Galaxy. The Sculptor Galaxy and the companion galaxies
NGC 247,
PGC 2881,
PGC 2933,
Sculptor-dE1, and
UGCA 15 form a gravitationally-bound core near the center of the group. Most other galaxies associated with the Sculptor Group are only weakly gravitationally bound to this core.
Starburst NGC 253's starburst has created several
super star clusters on NGC 253's center (discovered with the aid of the Hubble Space Telescope): one with a mass of
solar masses, and
absolute magnitude of at least −15, and two others with solar masses and absolute magnitudes around −11; later studies have discovered an even more massive cluster heavily obscured by NGC 253's
interstellar dust with a mass of solar masses, an age of around years, and rich in
Wolf–Rayet stars. The super star clusters are arranged in an ellipse around the center of NGC 253, which from the Earth's perspective appears as a flat line.
Star formation is also high in the northeast of NGC 253's disk, where a number of
red supergiant stars can be found, and in its
halo there are young stars as well as some amounts of
neutral hydrogen. This, along with other peculiarities found in NGC 253, suggest that a gas-rich
dwarf galaxy collided with it 200 million years ago, disturbing its disk and starting the present starburst. As happens in other galaxies suffering strong star formation such as
Messier 82,
NGC 4631, or
NGC 4666, the
stellar winds of the massive stars produced in the starburst as well as their deaths as
supernovae have blown out material to NGC 253's halo in the form of a
superwind that seems to be inhibiting star formation in the galaxy.
Novae and Supernovae Although supernovae are generally associated with starburst galaxies, only one has been detected within the Sculptor Galaxy. SN 1940E (type unknown, mag. 14.5) was discovered by
Fritz Zwicky on 22 November 1940, located approximately 54″ southwest of the galaxy's nucleus. NGC 253 is close enough that classical
novae can also be detected. The first confirmed nova in this galaxy was discovered by
BlackGEM at magnitude 19.6 on 12 July 2024, and designated AT 2024pid.
Central black hole Research suggests the presence of a
supermassive black hole in the center of this galaxy with a mass estimated to be 5 million times that of the Sun, which is slightly heavier than
Sagittarius A*.
Distance estimates At least two techniques have been used to measure distances to Sculptor in the past ten years. Using the
planetary nebula luminosity function (PNLF) method, an estimate of 10.89 million light years (or Mly; 3.34
Megaparsecs, or Mpc) was achieved in 2005. The Sculptor Galaxy is close enough that the
TRGB method may also be used to estimate its distance. The estimated distance to Sculptor using this technique in 2004 yielded (). A weighted average of the most reliable distance estimates gives a distance of (). ==Satellite galaxies==