NGC 247

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NGC 247
Wide Field Imager view of the spiral galaxy NGC 247.jpg
NGC 247 imaged by the Wide Field Imager (WFI) at ESO's La Silla Observatory in Chile
Observation data (J2000 epoch)
Constellation Cetus
Right ascension 00h 47m 08.5s [1]
Declination −20° 45 37 [1]
Distance 11.1 ± 1.2 Mly
Apparent magnitude  (V)9.9 [1]
Characteristics
Type SAB(s)d [1]
Apparent size  (V)21.4 × 6.9 [1] (70,000 light-years in diameter)
Other designations
HIPASS J0047-20, LEDA 2758, ESO-LV 540-0220, IRAS F00446-2101, 2MASX J00470855-2045374, ESO 540-22, IRAS 00446-2101, MCG-04-03-005, GLXY G113.8-83.5+144, KUG 0044-210, UGCA 11, PGC 2758, [1] Caldwell 62
Center of NGC 247 taken by Hubble Space Telescope. The centre of NGC 247.jpg
Center of NGC 247 taken by Hubble Space Telescope.

NGC 247 (also known as Caldwell 62 and commonly known as the Claw Galaxy [3] ) is an intermediate spiral galaxy (although it is sometimes classified as a dwarf 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 this was proved to be wrong. [4] NGC 247 is a member of the Sculptor Group, and is 70 000 light years in diameter. [5]

Contents

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. [6]

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. [7] Most other galaxies associated with the Sculptor Group are only weakly gravitationally bound to this core. [7] [8]

Related Research Articles

<span class="mw-page-title-main">Sculptor Group</span> Loosely grouped galaxy group in the constellation Sculptor

The Sculptor Group is a loose group of galaxies visible 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 (12.7 Mly).

<span class="mw-page-title-main">NGC 300</span> Galaxy in the constellation Sculptor

NGC 300 (also known as Caldwell 70 or the Sculptor Pinwheel Galaxy) is a spiral galaxy in the constellation Sculptor. It is one of the closest galaxies to the Local Group, and probably lies between the latter and the Sculptor Group. It is the brightest of the five main spirals in the direction of the Sculptor Group. It is inclined at an angle of 42° when viewed from Earth and shares many characteristics of the Triangulum Galaxy. It is 94,000 light-years in diameter, somewhat smaller than the Milky Way, and has an estimated mass of (2.9 ± 0.2) × 1010M.

<span class="mw-page-title-main">NGC 55</span> Galaxy in the constellation Sculptor

NGC 55, also known as the String of Pearls Galaxy, is a Magellanic type barred spiral galaxy located about 6.5 million light-years away in the constellation Sculptor. Along with its neighbor NGC 300, it is one of the closest galaxies to the Local Group, probably lying between the Milky Way and the Sculptor Group. It has an estimated mass of (2.0 ± 0.4) × 1010M.

<span class="mw-page-title-main">NGC 404</span> Galaxy in the constellation Andromeda

NGC 404 is a field galaxy located about 10 million light years away in the constellation Andromeda. It was discovered by William Herschel in 1784, and is visible through small telescopes. NGC 404 lies just beyond the Local Group and does not appear gravitationally bound to it. It is located within 7 arc-minutes of second magnitude star Mirach, making it a difficult target to observe or photograph and granting it the nickname "Mirach's Ghost".

<span class="mw-page-title-main">Messier 32</span> Dwarf elliptical galaxy in the constellation Andromeda

Messier 32 is a dwarf "early-type" galaxy about 2,650,000 light-years (810,000 pc) from the Solar System, appearing in the constellation Andromeda. M32 is a satellite galaxy of the Andromeda Galaxy (M31) and was discovered by Guillaume Le Gentil in 1749.

<span class="mw-page-title-main">Messier 94</span> Galaxy in the constellation Canes Venatici

Messier 94 is a spiral galaxy in the mid-northern constellation Canes Venatici. It was discovered by Pierre Méchain in 1781, and catalogued by Charles Messier two days later. Although some references describe M94 as a barred spiral galaxy, the "bar" structure appears to be more oval-shaped. The galaxy has two ring structures.

<span class="mw-page-title-main">Centaurus A/M83 Group</span> Group of galaxies in the constellations Centaurus, Hydra and Virgo

The Centaurus A/M83 Group is a complex group of galaxies in the constellations Hydra, Centaurus, and Virgo. The group may be roughly divided into two subgroups. The Cen A Subgroup, at a distance of 11.9 Mly, is centered on Centaurus A, a nearby radio galaxy. The M83 Subgroup, at a distance of 14.9 Mly, is centered on the Messier 83 (M83), a face-on spiral galaxy.

<span class="mw-page-title-main">Messier 106</span> Galaxy in the constellation Canes Venatici

Messier 106 is an intermediate spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth. M106 contains an active nucleus classified as a Type 2 Seyfert, and the presence of a central supermassive black hole has been demonstrated from radio-wavelength observations of the rotation of a disk of molecular gas orbiting within the inner light-year around the black hole. NGC 4217 is a possible companion galaxy of Messier 106. Besides the two visible arms, it has two "anomalous arms" detectable using an X-ray telescope.

<span class="mw-page-title-main">Sculptor Galaxy</span> Intermediate spiral galaxy in the constellation Sculptor

The Sculptor Galaxy is an intermediate spiral galaxy in the constellation Sculptor. The Sculptor Galaxy is a starburst galaxy, which means that it is currently undergoing a period of intense star formation.

<span class="mw-page-title-main">Sculptor Dwarf Irregular Galaxy</span> Irregular galaxy in the constellation Sculptor

The Sculptor Dwarf Irregular Galaxy (SDIG) is an irregular galaxy in the constellation Sculptor. It is a member of the NGC 7793 subgroup of the Sculptor Group.

<span class="mw-page-title-main">NGC 4725</span> Galaxy in the constellation Coma Berenices

NGC 4725 is an intermediate barred spiral galaxy with a prominent ring structure, located in the northern constellation of Coma Berenices near the north galactic pole. It was discovered by German-born British astronomer William Herschel on April 6, 1785. The galaxy lies at a distance of approximately 40 megalight-years from the Milky Way. NGC 4725 is the brightest member of the Coma I Group of the Coma-Sculptor Cloud, although it is relatively isolated from the other members of this group. This galaxy is strongly disturbed and is interacting with neighboring spiral galaxy NGC 4747, with its spiral arms showing indications of warping. The pair have an angular separation of 24′, which corresponds to a projected linear separation of 370 kly. A tidal plume extends from NGC 4747 toward NGC 4725.

<span class="mw-page-title-main">NGC 7793</span> Galaxy in the constellation Sculptor

NGC 7793 is a flocculent spiral galaxy in the southern constellation of Sculptor. It was discovered in 1826 by Scottish astronomer James Dunlop. The galaxy is located at a distance of 12.2 million light years and is receding with a heliocentric radial velocity of 227 km/s. NGC 7793 is one of the five brightest galaxies within the Sculptor Group.

<span class="mw-page-title-main">NGC 4945</span> Galaxy in the constellation Centaurus

NGC 4945 (also known as Caldwell 83) is a barred spiral galaxy in the constellation Centaurus, visible near the star Xi Centauri. The galaxy was discovered by James Dunlop in 1826 and is thought to be similar to the Milky Way Galaxy, although X-ray observations show that NGC 4945 has an unusual energetic Seyfert 2 nucleus that might house a supermassive black hole. Around the nucleus of the galaxy, there is a dense disk of dust and gas, along with many dense star clusters. This object has an estimated mass of 1.4+1.4
−0.7
×1011 M
.

The M94 Group is a loose, extended group of galaxies located about 13 million light-years away in the constellations Canes Venatici and Coma Berenices. The group is one of many groups that lies within the Virgo Supercluster and one of the closest groups to the Local Group.

A field galaxy is a galaxy that does not belong to a larger galaxy group or cluster and hence is gravitationally alone.

<span class="mw-page-title-main">Antlia Dwarf</span> Galaxy in the constellation Antlia

The Antlia Dwarf is a dwarf spheroidal/irregular galaxy. It lies about 1.3 Mpc from Earth in the constellation Antlia. It is the fourth and faintest member of the nearby Antlia-Sextans Group of galaxies. The galaxy contains stars of all ages, contains significant amounts of gas, and has experienced recent star formation. The Antlia Dwarf is believed to be tidally interacting with the small barred spiral galaxy NGC 3109.

<span class="mw-page-title-main">NGC 4236</span> Galaxy in the constellation Draco

NGC 4236 is a barred Magellanic spiral galaxy located in the constellation Draco.

<span class="mw-page-title-main">Maffei 2</span> Galaxy in the constellation Cassiopeia

Maffei 2 is an intermediate spiral galaxy about 10 million light-years away in the constellation Cassiopeia. Maffei 2 and Maffei 1 were both discovered by Paolo Maffei in 1968 from their infrared emission. Maffei 2 lies in the Zone of Avoidance and is about 99.5% obscured by the Milky Way's foreground dust clouds, and as a result is barely detectable at optical wavelengths. It had been suggested soon after its discovery that Maffei 2 may be a member of the Local Group, but it is now thought to be a member of another nearby group, the IC 342/Maffei Group, the galaxy group that is the closest to the Local Group.

<span class="mw-page-title-main">NGC 45</span> Spiral galaxy in the constellation Cetus

NGC 45 is a low surface brightness spiral galaxy in the equatorial constellation of Cetus. It was discovered on 11 November 1835 by the English astronomer John Herschel. The galaxy is located at a distance of 22 million light years and is receding with a heliocentric radial velocity of 466 km/s. It is located in the vicinity of the Sculptor Group, but is most likely a background galaxy.

<span class="mw-page-title-main">NGC 3621</span> Spiral galaxy in the constellation Hydra

NGC 3621 is a field spiral galaxy about 22 Mly (6.7 Mpc) away in the equatorial constellation of Hydra. It is comparatively bright and can be well seen in moderate-sized telescopes. The galaxy is around 93,000 ly (29,000 pc) across and is inclined at an angle of 66° from being viewed face on. It shines with a luminosity equal to 13 billion times that of the Sun. The morphological classification is SA(s)d, which indicates this is an ordinary spiral with loosely wound arms. There is no evidence for a bulge. Although it appears to be isolated, NGC 3621 belongs to the Leo spur.

References

  1. 1 2 3 4 5 6 "NASA/IPAC Extragalactic Database". Results for NGC 247. Retrieved 2006-12-19.
  2. "The centre of NGC 247". www.spacetelescope.org. Retrieved 6 October 2016.
  3. Chadwick, Stephen; Cooper, Ian (11 December 2012). Imaging the Southern Sky. Springer. p. 328. ISBN   978-1461447498.
  4. ""eso1107 — Photo Release: The Dusty Disc of NGC 247"". www.eso.org. Retrieved 24 Jul 2022.
  5. "NGC 247, an intermediate spiral galaxy in Cetus". Anne's Astronomy News (in Dutch). 2013-12-05. Retrieved 2020-04-16.
  6. Wagner-Kaiser, R.; Demaio, T.; Sarajedini, A.; Chakrabarti, S. (2014). "The Void in the Sculptor Group Spiral Galaxy NGC 247". Monthly Notices of the Royal Astronomical Society. 443 (4): 3260–3269. arXiv: 1407.0584 . Bibcode:2014MNRAS.443.3260W. doi: 10.1093/mnras/stu1327 .
  7. 1 2 Karachentsev, I. D. (2005). "The Local Group and Other Neighboring Galaxy Groups". Astronomical Journal . 129 (1): 178–188. arXiv: astro-ph/0410065 . Bibcode:2005AJ....129..178K. doi:10.1086/426368. S2CID   119385141.
  8. Karachentsev, I. D.; Grebel, E. K.; Sharina, M. E.; Dolphin, A. E.; Geisler, D.; Guhathakrta, P.; Hodge, P. W.; Karachentseva, V. E.; Sarajedini, A.; Seitzer, P. (2003). "Distances to nearby galaxies in Sculptor". Astronomy and Astrophysics . 404 (1): 93–111. arXiv: astro-ph/0302045 . Bibcode:2003A&A...404...93K. doi:10.1051/0004-6361:20030170. S2CID   54977869.