Hydra ( constellation ) - wikipedia Hydra ( constellation ) For other uses, see Hydra ( disambiguation ). Not to be confused with Hydrus. Hydra Constellation List of stars in Hydra Abbreviation Hya Genitive Hydrae Pronunciation / ˈhaɪdrə / genitive / ˈhaɪdriː / Symbolism the sea serpent Right ascension 8 -- 15 Declination − 20 ° Quadrant SQ2 Area 1303 sq. deg. ( 1st ) Main stars 17 Bayer / Flamsteed stars 75 Stars with planets 18 Stars brighter than 3.00 Stars within 10.00 pc ( 32.62 ly ) Brightest star Alphard ( α Hya ) ( 1.98 ) Messier objects Meteor showers Alpha Hydrids Sigma Hydrids Bordering constellations Antlia Cancer Canis Minor Centaurus Corvus Crater Leo Libra Lupus ( corner ) Monoceros Puppis Pyxis Sextans Virgo Visible at latitudes between + 54 ° and − 83 °. Best visible at 21 : 00 ( 9 p.m. ) during the month of April. Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. Also one of the longest at over 100 degrees, its southern end abuts Libra and Centaurus and its northern end borders Cancer. It has a long history, having been included among the 48 constellations listed by the 2nd century astronomer Ptolemy. It is commonly represented as a water snake. It should not be confused with the similarly named constellation of Hydrus. Contents 1 History and mythology 1.1 Western mythology 1.2 Mythology and equivalents in other cultures 2 Features 2.1 Stars 2.2 Deep - sky objects 2.3 Meteor showers 3 References 4 External links History and Mythology Western Mythology Hydra and surrounding constellations, from Urania 's Mirror ( 1825 ). The Greek constellation of Hydra is an adaptation of a Babylonian constellation : the MUL. APIN includes a `` serpent '' constellation ( MUL. DINGIR. MUŠ ) that loosely corresponds to Hydra. It is one of two Babylonian `` serpent '' constellations ( the other being the origin of the Greek Serpens ), a mythological hybrid of serpent, lion and bird. The shape of Hydra resembles a twisting snake, and features as such in some Greek myths. One myth associates it with a water snake that a crow served Apollo in a cup when it was sent to fetch water ; Apollo saw through the fraud, and angrily cast the crow, cup, and snake, into the sky. It is also associated with the monster Hydra, with its many heads, killed by Hercules, represented in another constellation. According to legend, if one of the hydra 's heads was cut off, two more would grow in its place. However, Hercules burned out the roots of the heads he severed to prevent them from growing again, and thus overcame the hydra. Mythology and equivalents in other cultures In Hindu Mythology the star that equivalents Hydra is Ashlesha. In Chinese astronomy, the stars that correspond to Hydra are located within the Vermilion Bird and the Azure Dragon. In Japanese culture, the stars are known as Nuriko. Features The constellation Hydra as it can be seen by the naked eye. Stars Despite its size, Hydra contains only one reasonably bright star, Alphard, designated Alpha Hydrae. It is an orange giant of magnitude 2.0, 177 light - years from Earth. Its traditional name means `` the solitary one ''. Beta Hydrae is a blue - white star of magnitude 4.3, 365 light - years from Earth. Gamma Hydrae is a yellow giant of magnitude 3.0, 132 light - years from Earth. Hydra has one bright binary star, Epsilon Hydrae, which is difficult to split in amateur telescopes ; it has a period of 1000 years and is 135 light - years from Earth. The primary is a yellow star of magnitude 3.4 and the secondary is a blue star of magnitude 6.7. However, there are several dimmer double stars and binary stars in Hydra. 27 Hydrae is a triple star with two components visible in binoculars and three visible in small amateur telescopes. The primary is a white star of magnitude 4.8, 244 light - years from Earth. The secondary, a binary star, appears in binoculars at magnitude 7.0 but is composed of a magnitude 7 and a magnitude 11 star ; it is 202 light - years from Earth. 54 Hydrae is a binary star 99 light - years from Earth, easily divisible in small amateur telescopes. The primary is a yellow star of magnitude 5.3 and the secondary is a purple star of magnitude 7.4. N Hydrae ( N Hya ) is a pair of stars of magnitudes 5.8 and 5.9. Struve 1270 ( Σ1270 ) consists of a pair of stars, magnitudes 6.4 and 7.4. The other main named star in Hydra is Sigma, σ, Hydrae, which also has the name of Minaruja, from the Arabic for snake 's nose. At magnitude 4.54, it is rather dim. The head of the snake corresponds to the Āshleshā Nakshatra, the lunar zodiacal constellation in Indian astronomy. Hydra is also home to several variable stars. R Hydrae is a Mira variable star 2000 light - years from Earth ; it is one of the brightest Mira variables at its maximum of magnitude 3.5. It has a minimum magnitude of 10 and a period of 390 days. V Hydrae is an unusually vivid red variable star 20,000 light - years from Earth. It varies in magnitude from a minimum of 9.0 to a maximum of 6.6. Along with its notable color, V Hydrae is also home to at least two exoplanets. U Hydrae is a semi-regular variable star with a deep red color, 528 light - years from Earth. It has a minimum magnitude of 6.6 and a maximum magnitude of 4.2 ; its period is 115 days. The constellation also contains the radio source Hydra A. Deep - Sky Objects Planetary nebula Abell 33 captured using ESO 's Very Large Telescope. Elliptical galaxy called NGC 3923. Hydra contains three Messier objects. M83, also known as the Southern Pinwheel Galaxy, is located on the border of Hydra and Centaurus, M68 is a globular cluster near M83, and M48 is an open star cluster in the western end of the serpent. NGC 3242 is a planetary nebula of magnitude 7.5, 1400 light - years from Earth. Discovered in 1785 by William Herschel, it has earned the nickname `` Ghost of Jupiter '' because of its striking resemblance to the giant planet. Its blue - green disk is visible in small telescopes and its halo is visible in larger instruments. M48 ( NGC 2548 ) is an open cluster that is visible to the naked eye under dark skies. Its shape has been described as `` triangular '' ; this 80 - star cluster is unusually large, more than half a degree in diameter, larger than the diameter of the full Moon. Ancient globular cluster NGC 6535. There are several globular clusters in Hydra. M68 ( NGC 4590 ) is a globular cluster visible in binoculars and resolvable in medium amateur telescopes. It is 31,000 light - years from Earth and of the 8th magnitude. NGC 5694 is a globular cluster of magnitude 10.2, 105,000 light - years from Earth. Also called `` Tombaugh 's Globular Cluster '', it is a Shapley class VII cluster ; the classification indicates that it has intermediate concentration at its nucleus. Though it was discovered as a non-stellar object in 1784 by William Herschel, its status as a globular cluster was not ascertained until 1932, when Clyde Tombaugh looked at photographic plates taken of the region near Pi Hydrae on 12 May 1931. M83 ( NGC 5236 ), the Southern Pinwheel Galaxy, is an 8th magnitude face - on spiral galaxy. It is easily observed in skies south of 40 ° N latitude, found by using 1, 2, 3, and 4 Centauri as guide stars. It has been host to six supernovae, more than any Messier object. Large amateur telescopes - above 12 inches aperture - reveal its spiral arms, bar, and small, bright nucleus. In a medium - sized amateur instrument, around 8 inches in aperture, the spiral arms become visible under good conditions. It is not perfectly symmetrical in the eyepiece, rather, the northwest side is flattened and the nucleus has a southwest - to - northeast bar. A smaller sister to the Milky Way, it is a grand design spiral galaxy 40,000 light - years across. NGC 2865 is relatively youthful and dynamic, with a rapidly rotating disc full of young stars and metal - rich gas. There are many other galaxies located in Hydra. NGC 3314, usually delineated as NGC 3314a and NGC 3314b, is a pair of galaxies that appear superimposed, despite the fact that they are not related or interacting in any way. The foreground galaxy, NGC 3314a, is at a distance of 140 million light - years, and is a face - on spiral galaxy. The background galaxy, NGC 3314b, is an oblique spiral galaxy, and has a nucleus that appears reddened because of NGC 3314a 's dusty disk. ESO 510 - G13 is a warped spiral galaxy located 150 million light - years from Earth. Though most galactic disks are flat because of their rate of rotation, their conformation can be changed, as is the case with this galaxy. Astronomers speculate that this is due to interactions with other galaxies. NGC 5068 may be a member of the M83 group, but its identity is disputed. It has a low surface brightness and has a diameter of 4.5 arcminutes. It is not perfectly circular, rather, it is elliptical and oriented on a west - northwest / east - southeast axis. However, it is of fairly uniform brightness throughout. Another notable galaxy is NGC 4993, an elliptical galaxy, where it host GW170817, GRB 170817A and SSS17a events from two neutron stars merger. Meteor Showers The Sigma Hydrids peak on December 6 and are a very active shower with an unknown parent body. The Alpha Hydrids are a minor shower that peaks between January 1 and 7. References Citations ^ Jump up to : Ridpath & Tirion 2001, pp. 158 -- 160. Jump up ^ White 2008, pp. 89, 180. Jump up ^ Ridpath & Tirion 2001, pp. 158 -- 159. Jump up ^ P.K. Chen ( 2007 ) A Constellation Album : Stars and Mythology of the Night Sky, p. 44 ( ISBN 978 - 1931559386 ). Jump up ^ `` ashlesha ''. www.selfrealisation.net. Retrieved 29 March 2018. Jump up ^ Levy 2005, p.. Jump up ^ `` Chance Meeting Creates Celestial Diamond Ring ''. ESO Press Release. Retrieved 10 April 2014. Jump up ^ `` Galactic onion ''. Retrieved 14 June 2015. Jump up ^ Nemiroff, R. ; Bonnell, J., eds. ( 31 March 1997 ). `` NGC 3242 : The ' Ghost of Jupiter ' Planetary Nebula ''. Astronomy Picture of the Day. NASA. Retrieved 2010 - 12 - 03. Jump up ^ Levy 2005, pp. 132 -- 133. Jump up ^ `` An ancient globule ''. www.spacetelescope.org. ESA / Hubble. Retrieved 29 December 2014. Jump up ^ Levy 2005, p. 173. ^ Jump up to : Dalrymple 2013, p. 38 - 40. Jump up ^ `` Young and dynamic ''. www.spacetelescope.org. ESA / Hubble. Retrieved 14 April 2015. ^ Jump up to : Wilkins & Dunn 2006, p.. Jump up ^ Dalrymple 2013, p. 41. Jump up ^ Cho, Adrian ( 16 October 2017 ). `` Merging neutron stars generate gravitational waves and a celestial light show ''. Science. doi : 10.1126 / science. aar2149. Retrieved 16 October 2017. Jump up ^ Abbott, B. P. ; et al. ( LIGO Scientific Collaboration & Virgo Collaboration ) ( 16 October 2017 ). `` GW170817 : Observation of Gravitational Waves from a Binary Neutron Star Inspiral ''. Physical Review Letters. 119 ( 16 ). arXiv : 1710.05832 ( gr - qc ). Bibcode : 2017PhRvL. 119p1101A. doi : 10.1103 / PhysRevLett. 119.161101. Jump up ^ Jenniskens 2012, p. 23. Jump up ^ Jenniskens 2012, p. 24. References Dalrymple, Les ( May 2013 ). `` Exploring the M83 Galaxy Group ''. Sky & Telescope. Jenniskens, Peter ( September 2012 ). `` Mapping Meteoroid Orbits : New Meteor Showers Discovered ''. Sky & Telescope. Levy, David H. ( 2005 ). Deep Sky Objects. Prometheus Books. ISBN 978 - 1 - 59102 - 361 - 6. Ridpath, Ian ; Tirion, Wil ( 2001 ). Stars and Planets Guide. Princeton University Press. ISBN 978 - 0 - 691 - 08913 - 3. 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. White, Gavin ( 2008 ). Babylonian Star - lore. Solaria Pubs. 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. External links Wikimedia Commons has media related to : Hydra ( constellation ) ( category ) Wikisource has the text of a 1911 Encyclopædia Britannica article about Hydra. The Deep Photographic Guide to the Constellations : Hydra Star Tales -- Hydra Warburg Institute Iconographic Database ( over 160 medieval and early modern images of Hydra ) Stars of Hydra Bayer α ( Alphard ) β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ σ ( Minchir ) τ τ υ ( Zhang ) υ φ φ φ χ χ ψ ω Flamsteed 6 ( a ) 9 10 12 ( D ) 14 15 17 19 20 21 23 24 25 26 27 ( P ) 28 29 33 ( A ) 34 37 44 47 48 50 51 ( k ) 52 ( l ) 54 ( m ) 55 56 57 58 ( E ) 59 60 3 Crt ( b ) 5 Crt ( b ) 6 Crt ( b ) 8 Crt 10 Crt 17 Crt ( N ) 18 Crt 20 Crt 22 Crt 23 Crt 26 Crt 29 Crt 14 Lib 30 Mon ( C ) 31 Mon ( F ) 2 Sex Variable U V X RT RW RX SX SZ TT TW VX VZ WZ AI AV CT DF EX EZ FG GK HQ HS II IL IY KU KZ LN LO LQ LR LV LX MO MX NS OY QT V335 V355 V406 V419 V478 HR 3212 3269 3271 3272 3285 3288 3295 3305 3338 3342 3374 3378 3383 3392 3411 3446 3458 3478 3480 3486 3493 3526 3529 3538 3554 3557 3564 3578 3584 3590 3596 3636 3638 3649 3651 3653 3675 3687 3704 3714 3741 3749 ( G ) 3750 3758 3760 3762 3763 3767 3772 3785 3788 3794 3796 3801 3802 3805 3808 3810 3822 3848 3858 ( I ) 3862 3908 3919 3921 3923 3931 3963 3965 3977 3986 3988 3991 4005 4011 4055 4068 4071 4076 4117 4123 4130 4149 4152 4157 4158 4162 4172 4190 4225 4261 4282 4298 4307 4328 4331 4339 4346 4373 4445 4498 4525 4542 4548 4553 4558 4579 4612 4628 4651 4723 4735 4774 4803 4810 4839 4857 4860 4918 4978 5090 5097 5098 5120 5128 5166 5167 5197 5209 5228 5246 5265 5309 5314 5324 5356 5399 5565 HD 68667 72659 74156 74685 75098 75217 76027 76478 78614 79481 79994 82943 83352 86226 86264 88806 90156 97344 105113 106500 107869 117033 121758 125279 Gliese Gliese 357 Gliese 433 Gliese 453 GJ 2066 GJ 3517 GJ 3634 Other BD - 3 2525 BD - 22 3467 CE 315 EC 14026 - 2647 HAT - P - 35 HAT - P - 42 HE 1327 - 2326 IRC - 20197 Kelu - 1 LHS 2065 LHS 3003 2MASS 0835 - 08 2MASS 1114 - 2618 PSR B0820 + 02 PSR B0834 + 06 TWA 5 WASP - 15 WASP - 25 WASP - 36 WISE 0855 − 0714 List The 88 modern constellations Andromeda Antlia Apus Aquarius Aquila Ara Aries Auriga Boötes Caelum Camelopardalis Cancer Canes Venatici Canis Major Canis Minor Capricornus Carina Cassiopeia Centaurus Cepheus Cetus Chamaeleon Circinus Columba Coma Berenices Corona Australis Corona Borealis Corvus Crater Crux Cygnus Delphinus Dorado Draco Equuleus Eridanus Fornax Gemini Grus Hercules Horologium Hydra Hydrus Indus Lacerta Leo Leo Minor Lepus Libra Lupus Lynx Lyra Mensa Microscopium Monoceros Musca Norma Octans Ophiuchus Orion Pavo Pegasus Perseus Phoenix Pictor Pisces Piscis Austrinus Puppis Pyxis Reticulum Sagitta Sagittarius Scorpius Sculptor Scutum Serpens Sextans Taurus Telescopium Triangulum Triangulum Australe Tucana Ursa Major Ursa Minor Vela Virgo Volans Vulpecula Lists of constellations Constellation history The 48 constellations listed by Ptolemy after 150 AD Andromeda Aquarius Aquila Ara Argo Navis Aries Auriga Boötes Cancer Canis Major Canis Minor Capricornus Cassiopeia Centaurus Cepheus Cetus Corona Australis Corona Borealis Corvus Crater Cygnus Delphinus Draco Equuleus Eridanus Gemini Hercules Hydra Leo Lepus Libra Lupus Lyra Ophiuchus Orion Pegasus Perseus Pisces Piscis Austrinus Sagitta Sagittarius Scorpius Serpens Taurus Triangulum Ursa Major Ursa Minor Virgo The 41 additional constellations added in the 16th and 17th centuries Vespucci or Corsalius early 16c : Crux Triangulum Australe Vopel 1536 : Coma Berenices Keyser & de Houtman 1596 : Apus Chamaeleon Dorado Grus Hydrus Indus Musca Pavo Phoenix Tucana Volans Plancius 1613 : Camelopardalis Columba Monoceros Habrecht 1621 : Reticulum Hevelius 1683 : Canes Venatici Lacerta Leo Minor Lynx Scutum Sextans Vulpecula de Lacaille 1763 : Antlia Caelum Carina Circinus Fornax Horologium Mensa Microscopium Norma Octans Pictor Puppis Pyxis Sculptor Telescopium Vela Obsolete constellations ( including Ptolemy 's Argo Navis ) Anser Antinous Apes Argo Navis Asterion Cancer Minor Cerberus Chara Custos Messium Felis Frederici Honores / Gloria Frederici Gallus Globus Aerostaticus Jordanus Lilium Lochium Funis Machina Electrica Malus Mons Maenalus Musca Borealis Noctua Officina Typographica Polophylax Psalterium Georgianum / Harpa Georgii Quadrans Muralis Ramus Pomifer Robur Carolinum Sceptrum Brandenburgicum Sceptrum et Manus Iustitiae Solarium Rangifer / Tarandus Taurus Poniatovii Telescopium Herschelii Testudo Tigris Triangulum Minus Turdus Solitarius Vespa Vultur cadens Vultur volans obsolete constellation names Apis Phoenicopterus Serpentarius Xiphias Coordinates : 10 00 00, − 20 ° 00 ′ 00 '' Retrieved from `` https://en.wikipedia.org/w/index.php?title=Hydra_(constellation)&oldid=833152985 '' Categories : Hydra ( constellation ) Constellations Constellations listed by Ptolemy Equatorial constellations Hidden categories : Wikipedia articles needing page number citations from August 2012 All articles with unsourced statements Articles with unsourced statements from November 2011 Talk Contents About Wikipedia Wikimedia Commons Afrikaans Asturianu Azərbaycanca বাংলা Bân - 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Question: what is the name of the largest constellation
Answer: Hydra