Astronomy:Crater (constellation)

From HandWiki
Short description: Constellation in the southern celestial hemisphere
Crater
Constellation
Crater
AbbreviationCrt
GenitiveCrateris
Pronunciation/ˈkreɪtər/,
genitive /krəˈtiːrɪs/
Symbolismthe cup
Right ascension 10h 51m 06.1297s– 11h 56m 23.6655s[1]
Declination−6.6621790°–−25.1957951°[1]
Area282 sq. deg. (53rd)
Main stars4
Bayer/Flamsteed
stars		12
Stars with planets7
Stars brighter than 3.00m0
Stars within 10.00 pc (32.62 ly)0
Brightest starδ Crt (Labrum) (3.57m)
Messier objects0
Meteor showersEta 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 is the latinization of the Greek krater, a type of cup used to water down wine. One of the 48 constellations listed by the second-century astronomer Ptolemy, it depicts a cup 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 in the constellation. Its two brightest stars, Delta Crateris of magnitude 3.56 and Alpha Crateris of magnitude 4.07, are ageing orange giant stars that are cooler and larger than the Sun. Beta Crateris is a binary star system composed of a white giant star and a white dwarf. Seven star systems have been found to host planets. A few notable galaxies, including Crater 2 and NGC 3981, and a famous quasar lie within the borders of the constellation.

Mythology

Old chart with various constellation figures overlaid onto stars
Corvus, Crater, and other constellations seen around Hydra, from Urania's Mirror (1825). Crater (centre) is depicted as a gold, double-handled cup with decorative filigree.

In the Babylonian star catalogues dating from at least 1100 BC, the stars of Crater were possibly incorporated with those of the crow Corvus in the Babylonian Raven (MUL.UGA.MUSHEN). British scientist John H. Rogers observed that the adjoining constellation Hydra signified Ningishzida, the god of the underworld in the Babylonian compendium MUL.APIN. He proposed that Corvus and Crater (along with the water snake Hydra) were death symbols and marked the gate to the underworld.[2] Corvus and Crater also featured in the iconography of Mithraism, which is thought to have been of middle-eastern origin before spreading into Ancient Greece and Rome.[3]

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 delays its journey as it finds some figs and waits for them to ripen before eating them. Finally, it retrieves the water in a cup and takes back a water snake, blaming it for drinking the water.[4] According to the myth, Apollo saw through the fraud, and angrily cast the crow, cup, and snake into the sky.[5] The three constellations were arranged in such a way that the crow was prevented from drinking from the cup, and hence seen as a warning against sinning against the gods.[4]

Phylarchus wrote of a different origin for Crater. He told how the city of Eleusa near Troy was beset by plague. Its ruler Demiphon consulted an oracle which decreed that a maiden should be sacrificed each year. Demiphon declared that he would choose a maiden by lottery, but he did not include his own daughters. One nobleman, Mastusius, objected, forcing Demiphon to sacrify his daughter. Later, Mastusius killed Demiphon's daughters and tricked the ruler in drinking a cup containing a mixture of their blood and wine. Upon finding out the deed, the king ordered Mastusius and the cup to be thrown into the sea. Crater signifies the cup.[4]

In other cultures

Crater as depicted on The Manuchihr Globe made in Mashhad 1632-33 AD. Adilnor Collection, Sweden.

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).[6] They depict, along with some stars from Hydra, Yi, the Red Bird's wings. Yi also denotes the 27th lunar mansion. Alternatively, Yi depicts a heroic bowman; his bow composed of other stars in Hydra.[7] In the Society Islands, Crater was recognized as a constellation called Moana-'ohu-noa-'ei-ha'a-moe-hara ("vortex-ocean-in-which-to-lose-crime").[8]

Characteristics

Covering 282.4 square degrees and hence 0.685% of the sky, Crater ranks 53rd of the 88 constellations in area.[9] It is bordered by Leo and Virgo to the north, Corvus to the east, Hydra to the south and west, and Sextans to the northwest. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Crt".[10] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of six segments (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between  10h 51m 14s and  11h 56m 24s, while the declination coordinates are between −6.66° and −25.20°.[11] Its position in the southern celestial hemisphere means that the whole constellation is visible to observers south of 65°N.[9][lower-alpha 1]

Features

Stars

Main page: Astronomy:List of stars in Crater
night sky. stars of constellation marked with lines
The constellation Crater as it can be seen by the naked eye.

The German cartographer Johann Bayer used the Greek letters alpha through lambda to label the most prominent stars in the constellation. Bode added more, though only Psi Crateris remains in use. John Flamsteed gave 31 stars in Crater and the segment of Hydra immediately below Crater Flamsteed designations, naming the resulting constellation Hydra et Crater. Most of these stars lie in Hydra.[12] The three brightest stars—Delta, Alpha, and Gamma Crateris—form a triangle located near the brighter star Nu Hydrae in Hydra.[13] Within the constellation's borders, there are 33 stars brighter than or equal to apparent magnitude 6.5.[lower-alpha 2][9]

Delta Crateris is the brightest star in Crater at magnitude 3.6. Located 163 ± 4 light-years away,[15] it is an orange giant star of spectral type K0III that is 1.0–1.4 times as massive as the Sun. An ageing star, it has cooled and expanded to 22.44 ± 0.28 times the Sun's radius. It is radiating 171.4 ± 9.0 as much power as the Sun from its outer envelope at an effective temperature of 4,408 ± 57 K.[16] Traditionally called Alkes "the cup",[17][lower-alpha 3] and marking the base of the cup is Alpha Crateris,[4] an orange-hued star of magnitude 4.1,[18] that is 141 ± 2 light-years from the Sun.[19] With an estimated mass 1.75 ± 0.24 times that of the Sun, it has exhausted its core hydrogen and expanded to 13.2 ± 0.55 times the Sun's diameter,[20] shining with 69 times its luminosity and an effective temperature of around 4600 K.[21]

With a magnitude of 4.5, Beta Crateris is a binary star system, consisting of a white-hued giant star of spectral type A1III and a white dwarf of spectral type DA1.4,[22] 296 ± 8 light-years from the Sun.[23] Much smaller than the primary, the white dwarf cannot be seen as a separate object, even by the Hubble Space Telescope.[24] Gamma Crateris is a double star, resolvable in small amateur telescopes.[25] The primary is a white main sequence star of spectral type A7V, that is an estimated 1.81 times as massive as the Sun,[26] while the secondary—of magnitude 9.6—has 75% the Sun's mass,[26] and is likely an orange dwarf. The two stars take at least 1150 years to orbit each other.[27] The system is 85.6 ± 0.8 light-years away from the Sun.[28]

Epsilon and Zeta Crateris mark the Cup's rim.[4] The largest naked eye star in the constellation,[29] Epsilon Crateris is an evolved K-type giant star with a stellar classification of K5 III.[30] It has about the same mass as the Sun, but has expanded to 44.7 times the Sun's radius.[31] The star is radiating 391 times the solar luminosity.[32] It is 366 ± 8 light-years distant from the Sun.[33] Zeta Crateris is a binary star system. The primary, component A, is a magnitude 4.95 evolved giant star with a stellar classification of G8 III.[34] It is a red clump star that is generating energy through the fusion of helium at its core.[35] Zeta Crateris has expanded to 13 times the radius of the Sun,[36] and shines with 157 times the luminosity of the Sun.[32] The secondary, component B, is a magnitude 7.84 star.[37] Zeta Crateris is a confirmed member of the Sirius supercluster[38] and is a candidate member of the Ursa Major Moving Group, a collection of stars that share a similar motion through space and may have at one time been members of the same open cluster.[39] The system is located 326 ± 9 light-years from the Sun.[40]

Variable stars are popular targets for amateur astronomers. Their observations provide valuable contributions to understanding star behaviour.[41] Located near Alkes is the red-hued R Crateris,[13] a semiregular variable star of type SRb and a spectral classification of M7. It ranges from magnitude 9.8 to 11.2 over an optical period of 160 days.[42] It is 770 ± 40 light-years distant from the Sun.[43] TT Crateris is a cataclysmic variable; a binary system composed of a white dwarf around as massive as the Sun in close orbit with an orange dwarf of spectral type K5V. The two orbit each other every 6 hours 26 minutes. The white dwarf strips matter off its companion, forming an accretion disk which periodically ignites and erupts. The star system has a magnitude of 15.9 when quiescent, brightening to 12.7 in outburst.[44] SZ Crateris is a magnitude 8.5 BY Draconis type variable star. It is a nearby star system located about 42.9 ± 1.0 light-years from the Sun,[45] and is a member of the Ursa Major Moving Group.[39]

File:A Galactic Traffic Jam - potw2009a.tif HD 98800, also known as TV Crateris, is a quadruple star system around 7–10 million years old, made up of two pairs of stars in close orbit. One pair has a debris disk that contains dust and gas orbiting them both. Spanning the distance between 3 and 5 astronomical units from the stars, it is thought to be a protoplanetary disk.[47] DENIS-P J1058.7-1548 is a brown dwarf less than 5.5% as massive as the Sun. With a surface temperature of between 1700 and 2000 K, it is cool enough for clouds to form. Variations in its brightness in visible and infrared spectra suggest it has some form of atmospheric cloud cover.[48]

HD 96167 is a star 1.31 ± 0.09 times as massive as the Sun, that has most likely exhausted its core hydrogen and begun expanding and cooling into a yellow subgiant with a diameter 1.86 ± 0.07 times that of the Sun, and 3.4 ± 0.2 times its luminosity. Analysis of its radial velocity revealed it has a planet with a minimum mass 68% that of Jupiter, which takes 498.9 ± 1.0 days to complete an orbit. With the orbital separation varying between 0.38 and 2.22 astronomical units, the orbit is highly eccentric.[49] The stellar system is 279 ± 1 light-years away from the Sun.[50] HD 98649 is a yellow main sequence star, classified as a G4V, that has the same mass and diameter as the Sun, but has only 86% of its luminosity. In 2012, a long-period ( 4951+607−465 days) planet companion, at least 6.8 times as massive as Jupiter, was discovered by radial velocity method. Its orbit was calculated to be highly eccentric, swinging out to 10.6 astronomical units away from its star, and hence a candidate for direct imaging.[51] BD-10°3166 is a metallic orange main sequence star of spectral type K3.0V, 268 ± 10 light-years distant from the Sun.[52] It was found to have a hot Jupiter-type planet that has a minimum mass of 48% of Jupiter's, and takes only 3.49 days to complete an orbit.[53] WASP-34 is a sun-like star of spectral type G5V that has 1.01 ± 0.07 times the mass and 0.93 ± 0.12 times the diameter of the Sun. It has a planet 0.59 ± 0.01 times as massive as Jupiter that takes 4.317 days to complete an orbit.[54] The system is 432 ± 3 light-years distant from the Sun.[55]

Deep-sky objects

File:A Galactic Gem NGC 3981.tif

The Crater 2 dwarf is a satellite galaxy of the Milky Way,[56] located approximately 380,000 light-years from the Sun.[57] NGC 3511 is a spiral galaxy seen nearly edge-on, of magnitude 11.0, located 2° west of Beta Crateris. Located 11' away is NGC 3513, a barred spiral galaxy.[58] NGC 3981 is a spiral galaxy with two wide and perturbed spiral arms.[59] It is a member of the NGC 4038 Group, which, along with NGC 3672 and NGC 3887, are part of a group of 45 galaxies known as the Crater Cloud within the Virgo Supercluster.[60]

RX J1131 is a quasar located 6 billion light-years away from the Sun. The black hole in the center of the quasar was the first black hole whose spin has ever been directly measured.[61] GRB 011211 was a gamma-ray burst (GRB) detected on December 11, 2001. The burst lasted 270 seconds, making it the longest burst that had ever been detected by X-ray astronomy satellite BeppoSAX up to that point.[62] GRB 030323 lasted 26 seconds and was detected on 23 March 2003.[63]

Meteor showers

The Eta Craterids are a faint meteor shower that takes place between 11 and 22 January, peaking around January 16 and 17, near Eta Crateris.[64]

See also

  • Crater (Chinese astronomy)

Notes

  1. ↑ While parts of the constellation technically rise above the horizon to observers between the 65°N and 83°N, stars within a few degrees of the horizon are to all intents and purposes unobservable.[9]
  2. ↑ Objects of magnitude 6.5 are among the faintest visible to the unaided eye in suburban-rural transition night skies.[14]
  3. ↑ from Arabic الكأس alka's[17]

References

  1. ↑ 1.0 1.1 "CRT". International Astronomical Unions. https://www.iau.org/static/public/constellations/pdf/CRT.pdf. 
  2. ↑ Rogers, John H. (1998). "Origins of the ancient constellations: I. The Mesopotamian traditions". Journal of the British Astronomical Association 108: 9–28. Bibcode: 1998JBAA..108....9R. 
  3. ↑ Rogers, John H. (1998). "Origins of the ancient constellations: II. The Mediterranean traditions". Journal of the British Astronomical Association 108: 79–89. Bibcode: 1998JBAA..108...79R. 
  4. ↑ 4.0 4.1 4.2 4.3 4.4 Condos, Theony (1997). Star Myths of the Greeks and Romans: A Sourcebook. Grand Rapids, Michigan: Phanes Press. pp. 119–23. ISBN 978-1609256784. https://books.google.com/books?id=9wPINXB4EAoC&pg=PA119. 
  5. ↑ Ridpath, Ian; Tirion, Wil (2001). Stars and Planets Guide. Princeton, New Jersey: Princeton University Press. p. 130. ISBN 978-0-691-17788-5. 
  6. ↑ "AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網" (in zh). Taichung, Taiwan: National Museum of Natural Science. 2006. http://aeea.nmns.edu.tw/2006/0607/ap060722.html. 
  7. ↑ Ridpath, Ian. "Corvus and Crater". Star Tales. self-published. http://www.ianridpath.com/startales/corvusandcrater.html#chinese. 
  8. ↑ Henry, Teuira (1907). "Tahitian astronomy". Journal of the Polynesian Society 16 (2): 101–04. http://www.jps.auckland.ac.nz/document//Volume_16_1907/Volume_16%2C_No._2/Tahitian_astronomy%2C_by_Miss_Teuira_Henry%2C_p_101-104/p1. 
  9. ↑ 9.0 9.1 9.2 9.3 Ian Ridpath. "Constellations: Andromeda–Indus". Star Tales. self-published. http://www.ianridpath.com/constellations1.html. 
  10. ↑ Russell, Henry Norris (1922). "The New International Symbols for the constellations". Popular Astronomy 30: 469. Bibcode: 1922PA.....30..469R. 
  11. ↑ "Crater, Constellation Boundary". The Constellations. International Astronomical Union. https://www.iau.org/public/themes/constellations/#crt. 
  12. ↑ Wagman, Morton (2003). Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others. Blacksburg, Virginia: The McDonald & Woodward Publishing Company. pp. 121–23, 390–92, 506–07. ISBN 978-0-939923-78-6. Bibcode: 2003lslm.book.....W. 
  13. ↑ 13.0 13.1 Arnold, H.J.P; Doherty, Paul; Moore, Patrick (1999). The Photographic Atlas of the Stars. Boca Raton, Florida: CRC Press. p. 140. ISBN 978-0-7503-0654-6. https://books.google.com/books?id=YjcvJUfnWBAC&pg=PA140. 
  14. ↑ Bortle, John E. (February 2001). "The Bortle Dark-Sky Scale". Sky & Telescope. http://www.skyandtelescope.com/resources/darksky/3304011.html?page=1&c=y. 
  15. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  16. ↑ Berio, P.; Merle, T.; Thévenin, F.; Bonneau, D.; Mourard, D.; Chesneau, O.; Delaa, O.; Ligi, R. et al. (2011). "Chromosphere of K giant stars. Geometrical extent and spatial structure detection". Astronomy & Astrophysics 535: A59. doi:10.1051/0004-6361/201117479. Bibcode: 2011A&A...535A..59B. 
  17. ↑ 17.0 17.1 Kunitzsch, Paul; Smart, Tim (2006). A Dictionary of Modern Star Names: A Short Guide to 254 Star Names and Their Derivations. Cambridge, Massachusetts: Sky Publishing. p. 31. ISBN 978-1-931559-44-7. 
  18. ↑ Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of stellar photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode: 2002yCat.2237....0D. 
  19. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  20. ↑ Reffert, Sabine; Bergmann, Christoph; Quirrenbach, Andreas; Trifonov, Trifon; Künstler, Andreas (2015). "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity". Astronomy & Astrophysics 574: 13. doi:10.1051/0004-6361/201322360. A116. Bibcode: 2015A&A...574A.116R. 
  21. ↑ Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". The Astronomical Journal 150 (3): 23. doi:10.1088/0004-6256/150/3/88. 88. Bibcode: 2015AJ....150...88L. 
  22. ↑ Holberg, J. B.; Oswalt, T. D.; Sion, E. M.; Barstow, M. A.; Burleigh, M. R. (2013). "Where are all the Sirius-like binary systems?". Monthly Notices of the Royal Astronomical Society 435 (3): 2077. doi:10.1093/mnras/stt1433. Bibcode: 2013MNRAS.435.2077H. 
  23. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  24. ↑ Barstow, M. A.; Bond, Howard E.; Burleigh, M. R.; Holberg, J. B. (2001). "Resolving Sirius-like binaries with the Hubble Space Telescope". Monthly Notices of the Royal Astronomical Society 322 (4): 891–900. doi:10.1046/j.1365-8711.2001.04203.x. Bibcode: 2001MNRAS.322..891B. 
  25. ↑ Monks, Neale (2010). Go-To Telescopes Under Suburban Skies. The Patrick Moore Practical Astronomy Series. New York, New York: Springer Science & Business Media. p. 113. ISBN 978-1-4419-6851-7. https://books.google.com/books?id=waO6tUtfblsC&pg=PA113. 
  26. ↑ 26.0 26.1 De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I. et al. (2013). "The VAST Survey – III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society 437 (2): 1216. doi:10.1093/mnras/stt1932. Bibcode: 2014MNRAS.437.1216D. 
  27. ↑ Kaler, James B. (Jim) (15 April 2011). "Gamma Crateris". Stars. University of Illinois. http://stars.astro.illinois.edu/sow/gammacrt.html. 
  28. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  29. ↑ Bagnall, Philip M. (2012). The Star Atlas Companion: What You Need to Know about the Constellations. New York, New York: Springer. p. 181. ISBN 978-1-4614-0830-7. https://books.google.com/books?id=KcIg02TKW6QC&pg=PA181. 
  30. ↑ Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey 5. Bibcode: 1999MSS...C05....0H. 
  31. ↑ Setiawan, J.; Pasquini, L.; da Silva, L.; Hatzes, A. P.; von der Lühe, O.; Girardi, L.; de Medeiros, J. R.; Guenther, E. (2004). "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch". Astronomy & Astrophysics 421: 241–54. doi:10.1051/0004-6361:20041042-1. Bibcode: 2004A&A...421..241S. 
  32. ↑ 32.0 32.1 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society 427 (1): 343–57. doi:10.1111/j.1365-2966.2012.21873.x. Bibcode: 2012MNRAS.427..343M.  Online data (HIP number needed)
  33. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  34. ↑ Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. 4. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode: 1988mcts.book.....H. 
  35. ↑ Alves, David R. (2000). "K-Band calibration of the red clump luminosity". The Astrophysical Journal 539 (2): 732–41. doi:10.1086/309278. Bibcode: 2000ApJ...539..732A. 
  36. ↑ Pasinetti-Fracassini, L.E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001). "Catalogue of Stellar Diameters (CADARS)". Astronomy & Astrophysics 367 (2): 521–24. doi:10.1051/0004-6361:20000451. Bibcode: 2001A&A...367..521P. 
  37. ↑ Mason, B. D.; Wycoff, G. L.; Hartkopf, W. I.; Douglass, G. G.; Worley, C. E. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal 122 (6): 3466–71. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M. http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds. 
  38. ↑ Eggen, Olin J. (1998). "The Sirius Supercluster and missing mass near the Sun". The Astronomical Journal 116 (2): 782–88. doi:10.1086/300465. Bibcode: 1998AJ....116..782E. 
  39. ↑ 39.0 39.1 King, Jeremy R.; Villarreal, Adam R.; Soderblom, David R.; Gulliver, Austin F.; Adelman, Saul J. (2003). "Stellar Kinematic Groups. II. A Reexamination of the Membership, Activity, and Age of the Ursa Major Group". The Astronomical Journal 125 (4): 1980–2017. doi:10.1086/368241. Bibcode: 2003AJ....125.1980K. https://tigerprints.clemson.edu/cgi/viewcontent.cgi?article=1248&context=physastro_pubs. 
  40. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  41. ↑ Tooke, Owen. "Variables: What Are They and Why Observe Them?". https://www.aavso.org/variables-what-are-they-why-observe-them. 
  42. ↑ Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (1 January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports 61 (1): 80–88. doi:10.1134/S1063772917010085. ISSN 1063-7729. Bibcode: 2017ARep...61...80S. http://www.sai.msu.su/gcvs/cgi-bin/search.cgi?search=R+Crt. 
  43. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  44. ↑ Sion, Edward M.; Gänsicke, Boris T.; Long, Knox S.; Szkody, Paula; Knigge, Christian; Hubeny, Ivan; deMartino, Domitilla; Godon, Patrick (2008). "Hubble Space Telescope STIS spectroscopy of long-period dwarf novae in quiescence". The Astrophysical Journal 681 (1): 543–53. doi:10.1086/586699. Bibcode: 2008ApJ...681..543S. 
  45. ↑ van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics 474 (2): 653–64. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. 
  46. ↑ "A Galactic Traffic Jam". https://www.spacetelescope.org/images/potw2009a/. 
  47. ↑ Ribas, Álvaro; Macías, Enrique; Espaillat, Catherine C.; Duchêne, Gaspard (2018). "Long-lived protoplanetary disks in multiple systems: The VLA view of HD 98800". The Astrophysical Journal 865 (1): 77. doi:10.3847/1538-4357/aad81b. Bibcode: 2018ApJ...865...77R. 
  48. ↑ Heinze, Aren N.; Metchev, Stanimir; Apai, Daniel; Flateau, Davin; Kurtev, Radostin; Marley, Mark; Radigan, Jacqueline; Burgasser, Adam J. et al. (2013). "Weather on other worlds I: Detection of periodic variability in the L3 dwarf DENIS-P J1058.7-1548 with precise multi-wavelength photometry". The Astrophysical Journal 767 (2): 173. doi:10.1088/0004-637X/767/2/173. Bibcode: 2013ApJ...767..173H. 
  49. ↑ Peek, John Asher; Johnson, Kathryn M. G.; Fischer, Debra A.; Marcy, Geoffrey W.; Henry, Gregory W.; Howard, Andrew W.; Wright, Jason T.; Lowe, Thomas B. et al. (2009). "Old, rich, and eccentric: two jovian planets orbiting evolved metal-rich stars". Publications of the Astronomical Society of the Pacific 121 (880): 613–20. doi:10.1086/599862. Bibcode: 2009PASP..121..613P. 
  50. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  51. ↑ Marmier, M.; Ségransan, D.; Udry, S.; Mayor, M.; Pepe, F.; Queloz, D.; Lovis, C.; Naef, D. et al. (2013). "The CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets". Astronomy and Astrophysics 551: A90. doi:10.1051/0004-6361/201219639. Bibcode: 2013A&A...551A..90M. 
  52. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  53. ↑ Butler, R. Paul; Vogt, Steven S.; Marcy, Geoffrey W.; Fischer, Debra A.; Henry, Gregory W.; Apps, Kevin (2000). "Planetary companions to the metal-rich Stars BD −10°3166 and HD 52265". The Astrophysical Journal 545 (1): 504–11. doi:10.1086/317796. Bibcode: 2000ApJ...545..504B. 
  54. ↑ Smalley, B.; Anderson, D. R.; Collier Cameron, A.; Hellier, C.; Lendl, M.; Maxted, P. F. L.; Queloz, D.; Triaud, A. H. M. J. et al. (2011). "WASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system". Astronomy & Astrophysics 526: 5. doi:10.1051/0004-6361/201015992. A130. Bibcode: 2011A&A...526A.130S. 
  55. ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  56. ↑ Torrealba, G.; Koposov, S. E.; Belokurov, V.; Irwin, M. (2016). "The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater". Monthly Notices of the Royal Astronomical Society 459 (3): 2370–78. doi:10.1093/mnras/stw733. Bibcode: 2016MNRAS.459.2370T. 
  57. ↑ Croswell, Ken (14 April 2016). "Never-before-seen galaxy spotted orbiting the Milky Way". New Scientist. https://www.newscientist.com/article/2084438-never-before-seen-galaxy-spotted-orbiting-the-milky-way/. 
  58. ↑ Bakich, Michael E. (2010). 1,001 Celestial Wonders to See Before You Die: The Best Sky Objects for Star Gazers. The Patrick Moore Practical Astronomy Series. New York, New York: Springer Science+Business Media. pp. 79–80. ISBN 978-1-4419-1777-5. https://books.google.com/books?id=qEhpS7d5ZdAC&pg=PA79. 
  59. ↑ "A Galactic Gem – ESO's FORS2 instrument captures stunning details of spiral galaxy NGC 3981" (in en-US). 12 September 2018. https://www.eso.org/public/australia/news/eso1830/. 
  60. ↑ Tully, R. Brent (1982). "The Local Supercluster" (in en). The Astrophysical Journal 257: 389–422. doi:10.1086/159999. ISSN 0004-637X. Bibcode: 1982ApJ...257..389T. 
  61. ↑ "Chandra & XMM-Newton Provide Direct Measurement of Distant Black Hole's Spin". Chandra X-ray Center. 5 March 2014. http://chandra.harvard.edu/photo/2014/rxj1131/. 
  62. ↑ Reeves, J. N.; Watson, D.; Osborne, J. P.; Pounds, K. A.; O'Brien, P. T.; Short, A. D. T.; Turner, M. J. L.; Watson, M. G. et al. (4 April 2002). "The signature of supernova ejecta measured in the X-ray afterglow of the Gamma Ray Burst 011211". Nature 416 (6880): 512–15. doi:10.1038/416512a. PMID 11932738. Bibcode: 2002Natur.416..512R. http://www.swift.ac.uk/Reeves_final_pages.pdf. 
  63. ↑ Vreeswijk, P. M.; Ellison, S. L.; Ledoux, C.; Wijers, R. A. M. J.; Fynbo, J. P. U.; Møller, P.; Henden, A.; Hjorth, J. et al. (June 2004). "The host of GRB 030323 at z = 3.372: A very high column density DLA system with a low metallicity". Astronomy & Astrophysics 419 (3): 927–940. doi:10.1051/0004-6361:20040086. Bibcode: 2004A&A...419..927V. 
  64. ↑ Levy, David H. (2008). David Levy's Guide to Observing Meteor Showers. Cambridge, United Kingdom: Cambridge University Press. pp. 105. ISBN 978-0-521-69691-3. https://books.google.com/books?id=jAr7HMnlPGUC&pg=PA105. 

External links

Coordinates: Sky map 11h 00m 00s, −16° 00′ 00″



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Crater_(constellation)&oldid=3348677"