Canis Minor

Coordinates: Sky map 08h 00m 00s, +05° 00′ 00″
Source: Wikipedia, the free encyclopedia.

Canis Minor
Constellation
71st)
Main stars2
Bayer/Flamsteed
stars		14
Stars with planets1
Stars brighter than 3.00m2
Stars within 10.00 pc (32.62 ly)4
Brightest starProcyon (α CMi) (0.34m)
Messier objects0
Meteor showersCanis-Minorids
Bordering
constellations
Visible at latitudes between +
90° and −75
°.
Best visible at 21:00 (9 p.m.) during the month of March.

Canis Minor /ˌkeɪnɪs ˈmaɪnər/ is a small constellation in the northern celestial hemisphere. In the second century, it was included as an asterism, or pattern, of two stars in Ptolemy's 48 constellations, and it is counted among the 88 modern constellations. Its name is Latin for "lesser dog", in contrast to Canis Major, the "greater dog"; both figures are commonly represented as following the constellation of Orion the hunter.

Canis Minor contains only two stars brighter than the fourth

main-sequence star, it has a white dwarf companion. Gomeisa is a blue-white main-sequence star. Luyten's Star is a ninth-magnitude red dwarf and the Solar System's next closest stellar neighbour in the constellation after Procyon. Additionally, Procyon and Luyten's Star are only 1.12 light-years away from each other,[2] and Procyon would be the brightest star in Luyten's Star's sky. The fourth-magnitude HD 66141, which has evolved into an orange giant towards the end of its life cycle, was discovered to have a planet in 2012. There are two faint deep-sky objects within the constellation's borders. The 11 Canis-Minorids are a meteor shower
that can be seen in early December.

History and mythology

Johann Bode
in his 1801 work Uranographia

Though strongly associated with the

rooster. This name may have also referred to the constellation Lepus.[3] DAR.LUGAL was also denoted DAR.MUŠEN and DAR.LUGAL.MUŠEN in Babylonia. Canis Minor was then called tarlugallu in Akkadian astronomy.[4]

Canis Minor was one of the original 48 constellations formulated by Ptolemy in his second-century Almagest, in which it was defined as a specific pattern (asterism) of stars; Ptolemy identified only two stars and hence no depiction was possible.[5] The Ancient Greeks called the constellation προκυων/Procyon, "coming before the dog", transliterated into Latin as Antecanis, Praecanis, or variations thereof, by Cicero and others. Roman writers also appended the descriptors parvus, minor or minusculus ("small" or "lesser", for its faintness), septentrionalis ("northerly", for its position in relation to Canis Major), primus (rising "first") or sinister (rising to the "left") to its name Canis.[5] In Greek mythology, Canis Minor was sometimes connected with the Teumessian Fox, a beast turned into stone with its hunter, Laelaps, by Zeus, who placed them in heaven as Canis Major (Laelaps) and Canis Minor (Teumessian Fox).[6][7] Eratosthenes accompanied the Little Dog with Orion, while Hyginus linked the constellation with Maera, a dog owned by Icarius of Athens.[8][9] On discovering the latter's death, the dog and Icarius' daughter Erigone took their lives and all three were placed in the sky—Erigone as Virgo and Icarius as Boötes.[9] As a reward for his faithfulness, the dog was placed along the "banks" of the Milky Way, which the ancients believed to be a heavenly river, where he would never suffer from thirst.[10]

The

Mirzam, now assigned to Orion, as part of both Canis Minor—the collar of the dog—and its modern home. The Arabic names for both Procyon and Gomeisa alluded to their proximity and resemblance to Sirius, though they were not direct translations of the Greek; Procyon was called ash-Shi'ra ash-Shamiya, the "Syrian Sirius" and Gomeisa was called ash-Shira al-Ghamisa, the Sirius with bleary eyes.[11] Among the Merazig of Tunisia, shepherds note six constellations that mark the passage of the dry, hot season. One of them, called Merzem, includes the stars of Canis Minor and Canis Major and is the herald of two weeks of hot weather.[13]

The ancient Egyptians thought of this constellation as Anubis, the jackal god.[14]

Atelier Typographique in this 1825 star chart from Urania's Mirror
.

Alternative names have been proposed: Johann Bayer in the early 17th century termed the constellation Fovea "The Pit", and Morus "Sycamine Tree". Seventeenth-century German poet and author Philippus Caesius linked it to the dog of Tobias from the Apocrypha.[5] Richard A. Proctor gave the constellation the name Felis "the Cat" in 1870 (contrasting with Canis Major, which he had abbreviated to Canis "the Dog"),[5] explaining that he sought to shorten the constellation names to make them more manageable on celestial charts.[15] Occasionally, Canis Minor is confused with Canis Major and given the name Canis Orionis ("Orion's Dog").[16]

In non-Western astronomy

In

Vermilion Bird of the South (南方朱雀, Nán Fāng Zhū Què). Procyon, Gomeisa and Eta Canis Minoris form an asterism known as Nánhé, the Southern River.[9][17] With its counterpart, the Northern River Beihe (Castor and Pollux), Nánhé was also associated with a gate or sentry. Along with Zeta and 8 Cancri, 6 Canis Minoris and 11 Canis Minoris formed the asterism Shuiwei, which literally means "water level". Combined with additional stars in Gemini, Shuiwei represented an official who managed floodwaters or a marker of the water level.[9] Neighboring Korea recognized four stars in Canis Minor as part of a different constellation, "the position of the water". This constellation was located in the Red Bird, the southern portion of the sky.[18]

dreamtime. Although their skin had turned to bark, they were able to speak with a human voice by rustling their leaves.[21]

The Aztec calendar was related to their cosmology. The stars of Canis Minor were incorporated along with some stars of Orion and Gemini into an asterism associated with the day called "Water".[22]

Characteristics

Lying directly south of Gemini's bright stars Castor and Pollux,[23] Canis Minor is a small constellation bordered by Monoceros to the south, Gemini to the north, Cancer to the northeast, and Hydra to the east. It does not border Canis Major; Monoceros is in between the two. Covering 183 square degrees, Canis Minor ranks seventy-first of the 88 constellations in size. It appears prominently in the southern sky during the Northern Hemisphere's winter.[24] The constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 14 sides. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 07h 06.4m and 08h 11.4m , while the declination coordinates are between 13.22° and −0.36°.[1] Most visible in the evening sky from January to March,[25] Canis Minor is most prominent at 10 p.m. during mid-February.[26] It is then seen earlier in the evening until July, when it is only visible after sunset before setting itself, and rising in the morning sky before dawn.[27] The constellation's three-letter abbreviation, as adopted by the International Astronomical Union in 1922, is "CMi".[28]

Features

Stars

See also: List of stars in Canis Minor
The constellation Canis Minor as it can be seen by the naked eye

Canis Minor contains only two stars brighter than fourth

spectral class B8 Ve.[34] Although fainter to Earth observers, it is much brighter than Procyon, and is 250 times as luminous and three times as massive as the Sun.[35] Although its variations are slight, Gomeisa is classified as a shell star (Gamma Cassiopeiae variable), with a maximum magnitude of 2.84 and a minimum magnitude of 2.92.[34] It is surrounded by a disk of gas which it heats and causes to emit radiation.[35]

Johann Bayer used the Greek letters Alpha to Eta to label the most prominent eight stars in the constellation, designating two stars as Delta (named Delta1 and Delta2).

arcseconds from the primary, the companion star is actually around 440 AU from the main star and takes around 5,000 years to orbit it.[48]

Near Procyon, three stars share the name

bright giant of spectral type B8II, Zeta lies around 623 light-years (191 parsecs) away from the Solar System.[51]

Lying 222 ± 7 light-years away with an apparent magnitude of 4.39,

HD 66141b, which was detected in 2012 by measuring the star's radial velocity. The planet has a mass around 6 times that of Jupiter and a period of 480 days.[53]

A

astroseismology.[58] AZ is of spectral type A5IV,[59] and ranges between magnitudes 6.44 and 6.51 over a period of 2.3 hours.[60] AD has a spectral type of F2III,[61] and has a maximum magnitude of 9.21 and minimum of 9.51, with a period of approximately 2.95 hours.[62] BI is of spectral type F2 with an apparent magnitude varying around 9.19[63] and a period of approximately 2.91 hours.[64]

At least three red giants are Mira variables in Canis Minor. S Canis Minoris, of spectral type M7e,[65] is the brightest, ranging from magnitude 6.6 to 13.2 over a period of 332.94 days.[24][66] V Canis Minoris ranges from magnitude 7.4 to 15.1 over a period of 366.1 days. Similar in magnitude is R Canis Minoris, which has a maximum of 7.3, but a significantly brighter minimum of 11.6. An S-type star, it has a period of 337.8 days.[67]

YZ Canis Minoris is a red dwarf of spectral type M4.5V and magnitude 11.2,[68] roughly three times the size of Jupiter and 20 light-years (6.1 parsecs) from Earth. It is a flare star, emitting unpredictable outbursts of energy for mere minutes, which might be much more powerful analogues of solar flares.[69] Luyten's Star (GJ 273) is a red dwarf star of spectral type M3.5V and close neighbour of the Solar System. Its visual magnitude of 9.9 renders it too faint to be seen with the naked eye,[70] even though it is only 12.39 light-years (3.80 parsecs) away.[71] Fainter still is PSS 544-7, an eighteenth-magnitude red dwarf around 20 per cent the mass of the Sun, located 685 light-years (210 parsecs) from Earth. First noticed in 1991, it is thought to be a cannonball star, shot out of a star cluster and now moving rapidly through space directly away from the galactic disc.[72]

The

accretion disc. This material builds up until it erupts dramatically.[73]

Deep-sky objects

Nebula Abell 24[74]

The Milky Way passes through much of Canis Minor, yet it has few deep-sky objects.[75] William Herschel recorded four objects in his 1786 work Catalogue of Nebulae and Clusters of Stars, including two he mistakenly believed were star clusters.[76] NGC 2459 is a group of five thirteenth- and fourteenth-magnitude stars that appear to lie close together in the sky but are not related.[77] A similar situation has occurred with NGC 2394, also in Canis Minor.[78] This is a collection of fifteen unrelated stars of ninth magnitude and fainter.[76]

Herschel also observed three faint galaxies, two of which are interacting with each other.[76] NGC 2508 is a lenticular galaxy of thirteenth magnitude, estimated at 205 million light-years' distance (63 million parsecs) with a diameter of 80,000 light-years (25,000 parsecs).[79] Named as a single object by Herschel, NGC 2402 is actually a pair of near-adjacent galaxies that appear to be interacting with each other. Only of fourteenth and fifteenth magnitudes, respectively, the elliptical and spiral galaxy are thought to be approximately 245 million light-years distant, and each measure 55,000 light-years in diameter.[80]

Meteor showers

The 11 Canis-Minorids, also called the Beta Canis Minorids,[81] are a meteor shower that arise near the fifth-magnitude star 11 Canis Minoris and were discovered in 1964 by Keith Hindley, who investigated their trajectory and proposed a common origin with the comet D/1917 F1 Mellish.[82] However, this conclusion has been refuted subsequently as the number of orbits analysed was low and their trajectories too disparate to confirm a link.[83] They last from 4 to 15 December, peaking over 10 and 11 December.[84]

References

  1. ^ a b c "Canis Minor, Constellation Boundary". The Constellations. Retrieved 25 May 2012.
  2. Centre de Données astronomiques de Strasbourg
    . Retrieved 23 February 2022.
  3. Bibcode:1998JBAA..108....9R
    .
  4. JSTOR 1006642
    .
  5. ^
    ISBN 978-0-486-21079-7
    .
  6. ^ Apollodorus, Bibliotheca 3,192.
  7. ISBN 978-1-4654-0353-7
    .
  8. ISBN 978-0-600-00893-4
    .
  9. ^ a b c d Ridpath, Ian. "Canis Minor". Star Tales. Retrieved 26 May 2012.
  10. ISBN 0-307-13667-1
    ).
  11. ^
    JSTOR 1522800
    .
  12. JSTOR 4629096
    .
  13. JSTOR 1479768
    .
  14. ^ Chartrand, p. 126.
  15. ^ Proctor, Richard Anthony (1870). A Star Atlas for the Library, the School and the Observatory. London, England: Longmans, Green. pp. 16–17.
  16. OCLC 882705
    .
  17. ^ 陳冠中; 陳輝樺 (16 July 2006). 天文教育資訊網 (in Chinese). AEEA (Activities of Exhibition and Education in Astronomy).
  18. S2CID 144879973
    .
  19. Bibcode:1941msra.book.....M
    .
  20. JSTOR 20700813
    .
  21. ISBN 978-0-9750908-0-0
    .
  22. S2CID 131473640
    .
  23. OCLC 7053675
    . (invalid isbn)
  24. ^
    ISBN 978-0-521-59889-7
    .
  25. ISBN 978-0-521-71405-1
    .
  26. ISBN 978-0-521-68435-4
    .
  27. ^ Rodmell, Paul. "Canis Major and Canis Minor, 2 Constellations for February". Royal Astronomical Society of New Zealand. Archived from the original on 14 January 2013. Retrieved 17 January 2013.
  28. Bibcode:1922PA.....30..469R
    .
  29. ^ "Procyon AB – Spectroscopic Binary". SIMBAD. Retrieved 8 January 2013.
  30. ^
    ISBN 978-0-691-08913-3
    .
  31. doi:10.1086/498894
    .
  32. ISBN 978-0-521-81803-2
    .
  33. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR
    .
  34. ^ a b "Bet CMi". International Variable Star Index. American Association of Variable Star Observers. 4 January 2010. Retrieved 13 January 2013.
  35. ^ a b Kaler, Jim. "Gomeisa (Beta Canis Minoris)". Stars. Retrieved 27 January 2012.
  36. ^ Wagman 2003, pp. 76–77.
  37. ^ Wagman 2003, p. 77.
  38. ^ Wagman 2003, p. 369.
  39. ^ a b c Wagman 2003, p. 504.
  40. ^
    ISBN 978-0-387-85354-3
    .
  41. ^ "Gamma Canis Minoris". SIMBAD. Retrieved 25 May 2012.
  42. ^ Kaler, Jim (19 March 2010). "Gamma Canis Minoris". Star of the Week. Retrieved 29 January 2013.
  43. ^ "Epsilon Canis Minoris". SIMBAD. Retrieved 25 May 2012.
  44. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR
    .
  45. ISBN 978-1-4614-0830-7
    .
  46. ^ "Eta Canis Minoris". SIMBAD. Retrieved 25 May 2012.
  47. ISBN 978-0-521-55491-6
    .
  48. ^ a b Kaler, Jim. "Eta and Delta-1 CMi". Stars. University of Illinois. Retrieved 22 August 2012.
  49. ^ "8 Canis Minoris". SIMBAD. Retrieved 13 January 2013.
  50. ^ "9 Canis Minoris". SIMBAD. Retrieved 13 January 2013.
  51. ^ a b "Zeta Canis Minoris". SIMBAD. Retrieved 6 September 2012.
  52. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR
    .
  53. ^ a b Zolotukhin, Ivan (2012). "Planet HD 66141 b". Extrasolar Planets Encyclopaedia. Retrieved 21 December 2012.
  54. S2CID 54984721
    .
  55. ^ Wagman 2003, p. 460.
  56. ^
    S2CID 15358380
    .
  57. ^ "BC CMi". International Variable Star Index. American Association of Variable Star Observers. 25 August 2009. Retrieved 13 January 2013.
  58. ^ Templeton, Matthew (16 July 2010). "Delta Scuti and the Delta Scuti Variables". Variable Star of the Season. AAVSO (American Association of Variable Star Observers). Retrieved 3 November 2012.
  59. ^ "V* AZ Canis Minoris – Variable of Delta Scuti type". SIMBAD. Retrieved 1 October 2012.
  60. ^ "AZ CMi". International Variable Star Index. AAVSO. 4 January 2010. Retrieved 14 January 2013.
  61. ^ "V* AD Canis Minoris – Variable of Delta Scuti type". SIMBAD. Retrieved 1 October 2012.
  62. ^ "AD Canis Minoris". International Variable Star Index. AAVSO. 4 January 2010. Retrieved 17 January 2013.
  63. ^ "V* BI Canis Minoris – Variable of Delta Scuti type". SIMBAD. Retrieved 1 October 2012.
  64. ^ "BI Canis Minoris". International Variable Star Index. AAVSO. 2 February 2011. Retrieved 17 January 2013.
  65. ^ "S Canis Minoris". SIMBAD. Retrieved 27 August 2012.
  66. ^ "S CMi". International Variable Star Index. AAVSO. 4 January 2010. Retrieved 14 January 2013.
  67. ISBN 978-0-521-89935-2
    .
  68. ^ "V* YZ Canis Minoris – Variable of BY Draconis Type". SIMBAD. Retrieved 1 October 2012.
  69. ^ "First Flares on a Distant Star". New Scientist: 305. 4 February 1982.
  70. ^ "The One Hundred Nearest Stars". Atlanta, Georgia: Georgia State University Astronomy. 1 January 2012. Archived from the original on 13 May 2012. Retrieved 1 October 2012.
  71. ^ "LHS 33 – High Proper-motion Star". SIMBAD. Retrieved 5 October 2012.
  72. doi:10.1016/j.newast.2005.04.001
    .
  73. Bibcode:2009JBAA..119..340S
    .
  74. ^ "Red and Long Dead". eso.org. Retrieved 8 July 2019.
  75. ISBN 978-1-85233-742-1
    .
  76. ^
    ISBN 978-0-521-76892-4
    .
  77. ^ Seligman, Courtney. "NGC Objects: NGC 2450 – 2499". Celestial Atlas. Retrieved 25 May 2012.
  78. ^ Seligman, Courtney. "NGC Objects: NGC 2350 – 2399". Celestial Atlas. Retrieved 25 May 2012.
  79. ^ Seligman, Courtney. "NGC Objects: NGC 2500 – 2549". Celestial Atlas. Retrieved 25 May 2012.
  80. ^ Seligman, Courtney. "NGC Objects: NGC 2400 – 2449". Celestial Atlas. Retrieved 25 May 2012.
  81. ISBN 978-0-521-85349-1
    .
  82. S2CID 4170596
    .
  83. S2CID 119297606
    .
  84. ISBN 978-0-521-69691-3
    .

Sources

External links

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