Fornax

This article is about a constellation of stars. For the Roman goddess, see Fornax (mythology).
Fornax
Constellation

Abbreviation For
Genitive Fornacis
Pronunciation /ˈfɔːrnæks/, genitive /fɔːrˈneɪsᵻs/
Symbolism the brazier
Right ascension 3
Declination −30
Family La Caille
Quadrant SQ1
Area 398 sq. deg. (41st)
Main stars 2
Bayer/Flamsteed
stars		 27
Stars with planets 7
Stars brighter than 3.00m 0
Stars within 10.00 pc (32.62 ly) 2
Brightest star α For (3.80m)
Nearest star LP 944-20
(16.20 ly, 4.97 pc)
Messier objects None
Meteor showers None
Bordering
constellations		 Cetus
Sculptor
Phoenix
Eridanus
Visible at latitudes between +50° and −90°.
Best visible at 21:00 (9 p.m.) during the month of December.

Fornax (/ˈfɔːrnæks/) is a constellation in the southern sky. Its name is Latin for furnace. It was named by French astronomer Nicolas Louis de Lacaille in 1756. Fornax is one of the 88 modern constellations.

History

Fornax Chemica can be seen below Cetus in this card from Urania's Mirror (1825).

De Lacaille originally called the constellation "Fornax Chemica" (the chemical furnace),[1] representing a small solid fuel vessel used for heating chemical experiments.

Notable features

The constellation Fornax as it can be seen by the naked eye.

Stars

Alpha Fornacis is a binary star that can be resolved by small amateur telescopes. The primary is a yellow-tinged main-sequence star of magnitude 3.9 and the secondary is a yellow star of magnitude 6.5; the secondary may actually be a variable star. It has a period of 300 years and is 46 light-years from Earth. Beta Fornacis is a yellow-hued giant star of magnitude 4.5, 169 light-years from Earth.[1]

Deep-sky objects

Four globular clusters in Fornax.[2]

Fornax has been the target of investigations into the furthest reaches of the universe. The Hubble Ultra Deep Field is located within Fornax, and the Fornax Cluster, a small cluster of galaxies, lies primarily within Fornax. At a meeting of the Royal Astronomical Society in Britain, a team from University of Queensland described 40 unknown "dwarf" galaxies in this constellation; follow-up observations with the Hubble Space Telescope and the European Southern Observatory's Very Large Telescope revealed that ultra compact dwarfs are much smaller than previously known dwarf galaxies, about 120 light-years (37 pc) across.[3]

NGC 1049 is a globular cluster 500,000 light-years from Earth. It is in the Fornax Dwarf Galaxy.[4]

UDFj-39546284, is a candidate protogalaxy located in Fornax,[5][6][7][8] although recent analyses have suggested it is likely to be a lower redshift source.[9][10]

HIP 13044 b is an exoplanet in the constellation, reported in November 2010, that was discovered to have originated outside of the galaxy.[11]

NGC 1097 is a barred spiral galaxy in Fornax, about 60 million light-years from Earth. At magnitude 9, it is visible in medium amateur telescopes.[12] It is notable as a Seyfert galaxy with strong spectral emissions indicating ionized gases and a central supermassive black hole.

NGC 1365 is another barred spiral galaxy located at a distance of 60 million light-years from Earth. Like NGC 1097, it is also a Seyfert galaxy. Its bar is a center of star formation and shows extensions of the spiral arms' dust lanes. The bright nucleus indicates the presence of an active galactic nucleus - a galaxy with a supermassive black hole at the center, accreting matter from the bar.[13] It is a 10th magnitude galaxy associated with the Fornax Cluster.[12]

NGC 1360 is a planetary nebula in Fornax with a magnitude of approximately 9.0, 978 light-years from Earth. Its central star is of magnitude 11.4, an unusually bright specimen. It is five times the size of the famed Ring Nebula in Lyra at 6.5 arcminutes. Unlike the Ring Nebula, NGC 1360 is clearly elliptical.[14]

Fornax A is a radio galaxy with extensive radio lobes that corresponds to the optical galaxy NGC 1316, a 9th-magnitude galaxy.[1] One of the closer active galaxies to Earth at a distance of 80 million light-years, Fornax A appears in the optical spectrum as a large elliptical galaxy with dust lanes near its core. These dust lanes have caused astronomers to discern that it recently merged with a small spiral galaxy. Because it has a high rate of type Ia supernovae, NGC 1316 has been used to determine the size of the universe. The jets producing the radio lobes are not particularly powerful, giving the lobes a more diffuse, knotted structure due to interactions with the intergalactic medium.[13] Associated with this peculiar galaxy is an entire cluster of galaxies.[1]

The Fornax Dwarf galaxy is a dwarf galaxy that is part of the Local Group of galaxies. It is not visible in amateur telescopes, despite its relatively small distance of 500,000 light-years.[1]

Equivalents

In Chinese astronomy, the stars that correspond to Fornax are located within the White Tiger of the West (西方白虎, Xī Fāng Bái Hǔ).[15]

See also

References

  1. 1 2 3 4 5 Ridpath & Tirion 2001, pp. 148-149.
  2. ↑ "Four globular clusters in Fornax". www.spacetelescope.org. ESA/Hubble. Retrieved 21 November 2014.
  3. ↑ Hilker M. et. al., 2007
  4. ↑ Levy 2005, p. 176.
  5. ↑ Wall, Mike (December 12, 2012). "Ancient Galaxy May Be Most Distant Ever Seen". Space.com. Retrieved December 12, 2012. 13.75 Big Bang - 0.38 = 13.37
  6. ↑ NASA, "NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe", 26 January 2011
  7. ↑ "Hubble finds a new contender for galaxy distance record". Space Telescope (heic1103 - Science Release). 26 January 2011. Retrieved 2011-01-27.
  8. ↑ HubbleSite, "NASA's Hubble Finds Most Distant Galaxy Candidate Ever Seen in Universe", STScI-2011-05, 26 January 2011
  9. ↑ "A Tentative Detection of an Emission Line at 1.6 mum for the z ~ 12 Candidate UDFj-39546284". The Astrophysical Journal 765: L2. 2013. arXiv:1301.0317. Bibcode:2013ApJ...765L...2B. doi:10.1088/2041-8205/765/1/l2.
  10. ↑ "Photometric Constraints on the Redshift of z ~ 10 Candidate UDFj-39546284 from Deeper WFC3/IR+ACS+IRAC Observations over the HUDF". The Astrophysical Journal 765: L16. 2013. arXiv:1211.3105. Bibcode:2013ApJ...765L..16B. doi:10.1088/2041-8205/765/1/l16.
  11. ↑ "'Alien' planet detected circling dying star". BBC News. 18 November 2010. Retrieved 20 November 2010.
  12. 1 2 Ridpath Tirion, pp. 148-149.
  13. 1 2 Wilkins, Jamie; Dunn, Robert (2006). 300 Astronomical Objects: A Visual Reference to the Universe. Buffalo, New York: Firefly Books. ISBN 978-1-55407-175-3.
  14. ↑ Levy 2005, pp. 134-135.
  15. ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日

External links

Wikimedia Commons has media related to Fornax.

Coordinates: 03h 00m 00s, −30° 00′ 00″

This article is issued from Wikipedia - version of the Friday, May 06, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.