Sculptor Group
Encyclopedia
The Sculptor Group is a loose group of galaxies near the south galactic pole. The group is one of the closest groups of galaxies to the Local Group
; the distance to the center of the group from the Milky Way
is approximately 3.9 Mpc
.
The Sculptor Galaxy
(NGC 253) and a few other galaxies form a gravitationally-bound core in the center of this group. A few other galaxies at the periphery may be associated with the group but may not be gravitationally bound. Because most of the galaxies in this group are actually weakly graviationally bound, the group may also be described as a filament
.
Note that the object names used in the above table differ from the names used by Karachentsev and collaborators. NGC, IC, UGC, and PGC
numbers have been used when possible to allow for easier referencing.
, the spiral galaxy NGC 300
, and their companion galaxies have been considered by many researchers to be part of this group. However, recent distance measurements to these and other galaxies in the same region of the sky show that NGC 55, NGC 300, and their companions may simply be foreground galaxies that are physically unassociated with the Sculptor Group.
Local Group
The Local Group is the group of galaxies that includes Earth's galaxy, the Milky Way. The group comprises more than 30 galaxies , with its gravitational center located somewhere between the Milky Way and the Andromeda Galaxy...
; the distance to the center of the group from the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
is approximately 3.9 Mpc
Parsec
The parsec is a unit of length used in astronomy. It is about 3.26 light-years, or just under 31 trillion kilometres ....
.
The Sculptor Galaxy
Sculptor Galaxy
The Sculptor Galaxy is an intermediate spiral galaxy in the constellation Sculptor...
(NGC 253) and a few other galaxies form a gravitationally-bound core in the center of this group. A few other galaxies at the periphery may be associated with the group but may not be gravitationally bound. Because most of the galaxies in this group are actually weakly graviationally bound, the group may also be described as a filament
Galaxy filament
In physical cosmology, galaxy filaments, also called supercluster complexes or great walls, are, so far, the largest known cosmic structures in the universe. They are massive, thread-like structures with a typical length of 50 to 80 megaparsecs h-1 that form the boundaries between large voids in...
.
Members
The table below lists galaxies that have been identified as associated with the Sculptor Galaxy (and hence associated with the group) by I. D. Karachentsev and collaborators.| Name | Type | R.A. Right ascension Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:... (J2000) |
Dec. Declination In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and... (J2000) |
Redshift Redshift In physics , redshift happens when light seen coming from an object is proportionally increased in wavelength, or shifted to the red end of the spectrum... (km/s Second The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock.... ) |
Apparent Magnitude Apparent magnitude The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere... |
|---|---|---|---|---|---|
| IC 1574 | IM(s)m | 363 ± 4 | 15.1 | ||
| NGC 59 | SA(rs)0 | 362 ± 10 | 13.1 | ||
| NGC 247 NGC 247 NGC 247 is an Intermediate spiral galaxy about 11.1 Mly away in the constellation Cetus. This distance was confirmed in late February 2011. Previous measurements showed that the galaxy was about 12.2 Mly away, but was proved to be wrong... |
SAB(s)d | 156 ± 2 | 9.9 | ||
| NGC 625 NGC 625 NGC 625 is a barred spiral galaxy about 12.7 Mly away in the constellation Phoenix. NGC 625 is a member of the Sculptor Group.... |
SB(s)m | 396 ± 1 | 11.7 | ||
| NGC 7793 NGC 7793 NGC 7793 is a spiral galaxy about 12.7 million light-years away in the constellation Sculptor. It was discovered in 1826 by James Dunlop.-Galaxy group information:... |
SA(s)d | 227 ± 2 | 10.0 | ||
| PGC 2881 | IABm | 16.5 | |||
| PGC 2933 | IAB(s)m pec | 16.6 | |||
| PGC 6430 | IB(s)m | 391 ± 2 | 12.7 | ||
| Sculptor-dE1 | dE | 16.9 | |||
| Sculptor Dwarf Irregular Galaxy Sculptor Dwarf Irregular Galaxy The Sculptor Dwarf Irregular Galaxy is an irregular galaxy in the constellation Sculptor. The galaxy was discovered in 1976.-Nearby galaxies and galaxy group information:... (PGC 621) |
IBm | 221 ± 6 | 15.5 | ||
| Sculptor Galaxy Sculptor Galaxy The Sculptor Galaxy is an intermediate spiral galaxy in the constellation Sculptor... (NGC 253) |
SAB(s)c | 243 ± 2 | 8.0 | ||
| UGCA 15 | IB(s)m | 295 ± 0 | 15.2 | ||
| UGCA 442 | SB(s)m | 267 ± 2 | 13.6 | ||
Note that the object names used in the above table differ from the names used by Karachentsev and collaborators. NGC, IC, UGC, and PGC
Principal Galaxies Catalogue
The Catalogue of Principal Galaxies is an astronomical catalogue published in 1989 that lists B1950 and J2000 equatorial coordinates and cross-identifications for 73,197 galaxies. 40,932 coordinates have standard deviations smaller than 10″. A total of 131,601 names from the 38 most...
numbers have been used when possible to allow for easier referencing.
Foreground galaxies
The irregular galaxy NGC 55NGC 55
NGC 55 is a barred irregular galaxy located about 7 million light-years away in the constellation Sculptor. Along with its neighbor NGC 300, it is one the closest galaxies to the Local Group, probably lying between us and the Sculptor Group.-Nearby galaxies and group information:NGC 55 and the...
, the spiral galaxy NGC 300
NGC 300
NGC 300 is a spiral galaxy in the constellation Sculptor. It is one of the closest galaxies to the Local Group, and probably lies between us and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group...
, and their companion galaxies have been considered by many researchers to be part of this group. However, recent distance measurements to these and other galaxies in the same region of the sky show that NGC 55, NGC 300, and their companions may simply be foreground galaxies that are physically unassociated with the Sculptor Group.