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) × 1010 M☉.[9]
| NGC 55 | |
|---|---|
.jpg) Irregular 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] | |
Nearby galaxies and group information
editNGC 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
editThe 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]
See also
editNotes
editReferences
edit- ^ 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.
- ^ a b c d e f g h "NASA/IPAC Extragalactic Database". Results for NGC 55. Retrieved 2006-10-17.
- ^ a b 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.
- ^ a b c 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.
- ^ a b "NGC 55". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-11-29.
- ^ 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.
- ^ Stoyan, Ronald; Schurig, Stephan (2014). interstellarum Deep Sky Atlas. Erlangen: Cambridge University Press; Oculum-Verlag GmbH. ISBN 978-1-107-50338-0. OCLC 920437579.
- ^ a b "New General Catalog Objects: NGC 50 - 99". cseligman.com. Retrieved 2017-12-12.
- ^ 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.
- ^ 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.
- ^ Jones, K. G. (1981). Webb Society Deep-Sky Observer's Handbook. Enslow Publishers. ISBN 978-0-89490-134-8. OL 8249797M.
- ^ Robert Burnham Jr. (1978). Burnham's Celestial Handbook. Vol. III. New York: Dover. p. 1733. ISBN 978-0-486-24065-7.
External links
edit
- NGC 55 in Sculptor
- SEDS: Spiral Galaxy NGC 55
- NGC 55 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images