Apus

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For the high school college credit course, see Advanced Placement United States History. For other uses, see Apus (disambiguation).
Apus
Constellation
Apus
Abbreviation Aps
Genitive Apodis
Pronunciation /ˈpəs/, genitive /ˈæpədɨs/
Symbolism The Bird-of-Paradise[1]
Right ascension 13h 51m 07.5441s–18h 27m 27.8395s[2]
Declination −67.4800797°–−83.1200714°[2]
Family Bayer
Area 206 sq. deg. (67th)
Main stars 4
Bayer/Flamsteed
stars
12
Stars with planets 2
Stars brighter than 3.00m 0
Stars within 10.00 pc (32.62 ly) 0
Brightest star α Aps (3.83m)
Nearest star HD 128400
(66.36 ly, 20.35 pc)
Messier objects None
Meteor showers None
Bordering
constellations
Triangulum Australe
Circinus
Musca
Chamaeleon
Octans
Pavo
Ara
Visible at latitudes between +5° and −90°.
Best visible at 21:00 (9 p.m.) during the month of July.

Apus is a faint constellation in the southern sky, first defined in the late 16th century. Its name means "no feet" in Greek, and it represents a bird-of-paradise (which were once believed to lack feet). It is bordered by Triangulum Australe, Circinus, Musca, Chamaeleon, Octans, Pavo and Ara. Its genitive is "Apodis".

History[edit]

Apus was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. It first appeared on a 35 cm diameter celestial globe published in 1597 or 1598 in Amsterdam by Plancius with Jodocus Hondius.[1][3][4] Plancius called the constellation Paradysvogel Apis Indica; the first word is Dutch for "bird of paradise", of genus Pteridophora, but the others are Latin for "Indian Bee". Apis (Latin for "bee") is presumably an error for avis ("bird").[1][4]

The name Apus is derived from the Greek apous, meaning "without feet". This referred to the Western misconception that the bird-of-paradise had no feet, which arose because the only specimens available in the West had their feet and wings removed.[1] Such specimens began to arrive in Europe in 1522, when the survivors of Ferdinand Magellan's expedition brought them home.[5]

After its introduction on Plancius's globe, the constellation's first known appearance in a celestial atlas was in Johann Bayer's Uranometria of 1603, where it was called "Apis Indica".[1][4]

Richard Allen reports Semler's assertion that de Houtman, who observed the southern constellations from the island of Sumatra, took his ideas for the formation of Apus (as well as Phoenix and Indus) from the Chinese, who knew the stars of Apus as the "Little Wonder Bird",[6] and that Semler's assertion was disputed by Ideler (though Ideler acknowledged the Chinese constellations).

Notable features[edit]

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

The most prominent deep-sky objects in Apus include the globular clusters NGC 6101 and IC 4499 as well as the spiral galaxy IC 4633.

Stars[edit]

  • α Apodis is an orange giant 411 light years away, with a magnitude of 3.8.[3][4]
  • β Apodis is an orange giant 158 light years away, with a magnitude of 4.2.[3]
  • γ Apodis is an orange giant 160 light years away, with a magnitude of 3.9.[3]
  • δ Apodis is a double star with a separation of 103 arcseconds.[4] δ1 is a red giant star located 765 light years away, with a magnitude of 4.7. δ2 is an orange giant star[4] located 663 light years away, with a magnitude of 5.3. The separate components can be resolved with binoculars, a telescope, or the naked eye.[3]
  • θ Apodis is a variable red giant at a distance of 328 light years with a period of approximately 4 months,[3] or 109 days.[4] It has a maximum magnitude of 4.8 and a minimum magnitude of 6.1.[4]

Deep-sky objects[edit]

  • NGC 6101 is a 14th magnitude globular cluster, located seven degrees north of γ Aps.[4]
  • IC 4499 is a loose globular cluster in the medium-far galactic halo.[8] Its apparent magnitude is 10.6,[9] and it is unique because it is younger than most other globular clusters in the same region as determined by its metallicity.[8]
  • IC 4633 is a very faint spiral galaxy [4] surrounded by a vast amount of Milky Way line-of-sight Integrated Flux Nebulae.

Equivalents[edit]

When the Ming Dynasty Chinese astronomer Xu Guangqi adapted the European southern hemisphere constellations to the Chinese system in The Southern Asterisms, he combined Apus with some of the stars in Octans to form the "Exotic Bird" (異雀, Yìquè).[10]

References[edit]

Citations
  1. ^ a b c d e Ridpath, Ian. "Apus". Star Tales. Retrieved 10 April 2012. 
  2. ^ a b "Apus, constellation boundary". The Constellations (International Astronomical Union). Retrieved 14 February 2014. 
  3. ^ a b c d e f Ridpath 2001, pp. 76-77.
  4. ^ a b c d e f g h i j Plotner, Tammy (13 October 2008). "Apus". Universe Today. Retrieved 22 April 2012. 
  5. ^ Staal 1988, p. 252.
  6. ^ Richard H. Allen (1899) Star Names: Their Lore and Meaning, p. 45 <http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Apus*.html>
  7. ^ "IC 4499: A globular cluster’s age revisited". ESA/Hubble Picture of the Week. Retrieved 5 August 2014. 
  8. ^ a b Ferraro, I.; Ferraro, F.R.; Pecci, F. Fusi; Corsi, C.E.; Buonanno, R. (August 1995). "Young globular clusters in the Milky Way: IC 4499". Monthly Notices of the Royal Astronomical Society (SAO/NASA ADS Astronomy Abstract Service) 275 (4): 1057–1076. Bibcode:1995MNRAS.275.1057F. doi:10.1093/mnras/275.4.1057. Retrieved 22 April 2012. 
  9. ^ Frommert, Hartmut. "IC 4499". Students for the Exploration and Development of Space. Retrieved 22 April 2012. 
  10. ^ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日
References
  • Ridpath, Ian (2001), Stars and Planets Guide, Princeton University Press, ISBN 0-691-08913-2 
  • Ridpath, Ian (2007), Stars and Planets Guide, Wil Tirion (4th ed.), Princeton University Press, ISBN 978-0-691-13556-4 
  • Staal, Julius D.W. (1988), The New Patterns in the Sky: Myths and Legends of the Stars, The McDonald and Woodward Publishing Company, ISBN 0-939923-04-1 

External links[edit]

Coordinates: Sky map 16h 00m 00s, −75° 00′ 00″