Crater (constellation)
Constellation | |
Abbreviation | Crt |
---|---|
Genitive | Crateris |
Pronunciation | /ˈkreɪtər/, genitive /krəˈtɪərᵻs/ |
Symbolism | the cup |
Right ascension | 11 |
Declination | −16 |
Family | Hercules |
Quadrant | SQ2 |
Area | 282 sq. deg. (53rd) |
Main stars | 4 |
Bayer/Flamsteed stars |
12 |
Stars with planets | 7 |
Stars brighter than 3.00m | 0 |
Stars within 10.00 pc (32.62 ly) | 0 |
Brightest star | δ Crt (Labrum) (3.57m) |
Nearest star | LHS 2358 (34.86 ly, 10.69 pc) |
Messier objects | 0 |
Meteor showers | Eta Craterids |
Bordering constellations |
Leo Sextans Hydra Corvus Virgo |
Visible at latitudes between +65° and −90°. Best visible at 21:00 (9 p.m.) during the month of April. |
Crater is a small constellation in the Southern Celestial Hemisphere. Its name means "cup" in Latin. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it depicts a raven that has been associated with the god Apollo and is perched on the back of Hydra the water snake.
There is no star brighter than third magnitude, Delta Crateris the brightest star with a magnitude of 3.56.
Contents
Mythology[edit]
Crater is identified with a story from Greek mythology in which a crow or raven serves Apollo, and is sent to fetch water, but it rests lazily on the journey, and after finally obtaining the water in a cup, takes back a water snake as an excuse. According to the myth, Apollo saw through the fraud, and angrily cast the crow, cup, and snake, into the sky. The constellations of Corvus the crow and Hydra the water-snake are also identified with this myth.[1]
Equivalents[edit]
In Chinese astronomy, the stars of Crater are located within the constellation of the Vermillion Bird of the South (南方朱雀, Nán Fāng Zhū Què).[2]
In the Society Islands, Crater was recognized as a constellation called Moana-ohu-noa-ei-haa-moe-hara.[3]
Notable features[edit]
Stars[edit]
Alpha Crateris, traditionally called Alkes, is an orange-hued giant star of magnitude 4.1, 159 ± 2 light-years from Earth.[4] Its traditional name means "the cup". Beta Crateris is a blue-white hued star of magnitude 4.5, 266 light-years from Earth. Gamma Crateris is a double star divisible in small amateur telescopes. The primary is a white star of magnitude 4.1, 84 light-years from Earth. The secondary is of magnitude 9.6. Delta Crateris is the brightest star in Crater at magnitude 3.6. 195 light-years away, it is an orange-hued giant star.[5]
R Crateris is a semi-regular variable of type SRb and a spectral classification of M7. It has a magnitude of 9.8-11.2 and an optical period of 160 days.
SZ Crateris is a magnitude 8.1 variable star. It is a nearby star system located about 44 light years from the Sun. It is also identified as Gliese 425, and in the past it was known as Abt's Star.[citation needed]
Named stars[edit]
Bayer | Name | Origin | Meaning |
---|---|---|---|
α | Alkes | Arabic | name of constellation |
β | Al Sharas | Arabic | the rib |
Deep-sky objects[edit]
NGC 3511 is a spiral galaxy with a slight bar, seen nearly from the edge, of type SBbc. It is a member of the galaxy cluster Abell 1060. This galaxy is magnitude 12, and is 4' × 1' in size. Right nearby, 30" away, is NGC 3513, another SB-class spiral.
NGC 3887 is a barred-spiral galaxy of type SBc, magnitude 11, with a diameter of 3.5'.
NGC 3981 is a spiral galaxy with two wide spiral arms, of type SBbc. It is magnitude 12 with a diameter of 3'. This galaxy was discovered by William Herschel in 1785.
RX J1131 is a quasar located 6 billion light years away from Earth. The black hole in the center of the quasar was the first black hole whose spin has ever been directly measured.[6]
Namesakes[edit]
USS Crater (AK-70) was a United States Navy Crater class cargo ship named after the constellation.
See also[edit]
References[edit]
- ^ Ridpath & Tirion 2001, p. 128.
- ^ (Chinese)AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 31 日
- ^ Makemson 1941, p. 282.
- ^ van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- ^ Ridpath & Tirion 2001, pp. 130-131.
- ^ Nola Taylor Redd (March 5, 2014). "Monster Black Hole Spins at Half the Speed of Light". Space.com. Retrieved March 5, 2014.
- Makemson, Maud Worcester (1941). The Morning Star Rises: an account of Polynesian astronomy. Yale University Press.
- Ridpath, Ian; Tirion, Wil (2001), Stars and Planets Guide, Princeton University Press, ISBN 0-691-08913-2
- Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0-00-725120-9. Princeton University Press, Princeton. ISBN 978-0-691-13556-4.
- Richard Hinckley Allen, The Stars, Their Lore and Legend, New York, Dover.
External links[edit]
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