NGC 55

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NGC 55
Irregular Galaxy NGC 55 (ESO 0914a).jpg
Magellanic barred spiral galaxy NGC 55 imaged by the La Silla Observatory
Observation data (J2000 epoch)
Constellation Sculptor [1]
Right ascension 00h 14m 53.6s [2]
Declination −39° 11′ 47.9″ [2]
Redshift 0.000437 [2]
Heliocentric radial velocity 131 ± 2 km/s [2]
Distance 6.5 ± 0.65 Mly
(2.00 ± 0.2 Mpc) [3] [4] [a]
Apparent magnitude  (V)7.87 [5] [6]
Characteristics
Type SB(s)m [2]
Mass (2.0 ± 0.4) × 1010  M☉
Size~68,500  ly (20.99  kpc) (estimated) [2]
Apparent size  (V)32.4′ × 5.6′ [2]
Other designations
PGC 1014, [2] Caldwell  72, 2MASS J00145360-3911478, IRAS F00124-3929, ESO 293-50, MCG -07-01-013 [5]

NGC 55, also known as the String of Pearls Galaxy, [7] is a Magellanic type barred spiral galaxy located about 6.5 million light-years away in the constellation Sculptor. It was discovered on 7 July 1826 by Scottish astronomer James Dunlop. [8] 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. [8] It has an estimated mass of (2.0 ± 0.4) × 1010M☉. [9]

Contents

Nearby galaxies and group information

NGC 55 and the spiral galaxy NGC 300 have traditionally been identified as members of the Sculptor Group, a nearby group of galaxies in the constellation of the same name. However, recent distance measurements indicate that the two galaxies actually lie in the foreground. [10]

It is likely that NGC 55 and NGC 300 form a gravitationally bound pair. [4]

Visual appearance

The Webb Society Deep-Sky Observer's Handbook [11] writes the following about NGC 55: "Nearly edge-on and appears asymmetrical with some signs of dust near the bulge, which is diffuse, broad and somewhat elongated with the south edge sharp; southeast of the bulge it is strongly curved and lined with 4 or 5 faint knots; north edge of the curve is sharp." Burnham calls it "one of the outstanding galaxies of the southern heavens", somewhat resembling a smaller version of the Large Magellanic Cloud. [12] In September 1897, the famous New York comet hunter Lewis Swift observed the galaxy from Echo Mountain, California with a 16-inch refractor. He mistook the galaxy's faint eastern section as a new find (even though John Herschel had drawn it) and that is how it got cataloged as IC 1537. [13]

See also

Notes

  1. ^ average(6.9 ± 0.7, [3] 7.5 ± 1.1 [4] ) = ((6.9 + 7.5) / 2) ± ((0.72 + 1.12)0.5 / 2) = 7.2 ± 0.7

References

  1. ↑ R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation and Cambridge University Press. ISBN   978-0-933346-51-2.
  2. 1 2 3 4 5 6 7 8 "NASA/IPAC Extragalactic Database". Results for NGC 55. Retrieved 2006-10-17.
  3. 1 2 Karachentsev, I. D.; Kashibadze, O. G. (2006). "Masses of the local group and of the M81 group estimated from distortions in the local velocity field". Astrophysics . 49 (1): 3–18. Bibcode:2006Ap.....49....3K. doi:10.1007/s10511-006-0002-6. S2CID   120973010.
  4. 1 2 3 van de Steene, G. C.; et al. (2006). "Distance determination to NGC 55 from the planetary nebula luminosity function". Astronomy and Astrophysics . 455 (3): 891–896. Bibcode:2006A&A...455..891V. doi: 10.1051/0004-6361:20053475 .
  5. 1 2 "NGC 55". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2009-11-29.
  6. ↑ Armando, Gil de Paz; et al. (2007). "The GALEX Ultraviolet Atlas of Nearby Galaxies". Astrophysical Journal Supplement Series . 173 (2): 185–255. arXiv: astro-ph/0606440 . Bibcode:2007ApJS..173..185G. doi:10.1086/516636. S2CID   119085482.
  7. ↑ Stoyan, Ronald; Schurig, Stephan (2014). interstellarum Deep Sky Atlas. Erlangen: Cambridge University Press; Oculum-Verlag GmbH. ISBN   978-1-107-50338-0. OCLC   920437579.
  8. 1 2 "New General Catalog Objects: NGC 50 - 99". cseligman.com. Retrieved 2017-12-12.
  9. ↑ Westmeier, T.; Koribalski, B. S.; Braun, R. (2013). "Gas and dark matter in the Sculptor group: NGC 55". Monthly Notices of the Royal Astronomical Society. 434 (4): 3511–3525. arXiv: 1307.2962 . doi: 10.1093/mnras/stt1271 .
  10. ↑ I. D. Karachentsev; et al. (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.
  11. ↑ Jones, K. G. (1981). Webb Society Deep-Sky Observer's Handbook . Enslow Publishers. ISBN   978-0-89490-134-8. OL   8249797M.
  12. ↑ Robert Burnham Jr. (1978). Burnham's Celestial Handbook. Vol. III. New York: Dover. p.  1733. ISBN   978-0-486-24065-7.
  13. ↑ Swift, L. (1898-09-01). "Catalogue No. 11 of Nebulae". Astronomische Nachrichten. 147 (13): 209–220. Bibcode:1898AN....147..209S. doi:10.1002/asna.18981471302. ISSN   0004-6337.