Features Aquarius (constellation)

1 features

1.1 stars
1.2 planetary systems
1.3 deep sky objects
1.4 meteor showers

features

the constellation aquarius can seen naked eye



stars

despite both prominent position on zodiac , large size, aquarius has no particularly bright stars, 4 brightest stars being less magnitude 2. however, recent research has shown there several stars lying within borders possess planetary systems.

the 2 brightest stars, alpha , beta aquarii, luminous yellow supergiants, of spectral types g0ib , g2ib respectively, once hot blue-white b-class main sequence stars 5 9 times massive sun. 2 moving through space perpendicular plane of milky way. shading alpha, beta aquarii brightest star in aquarius apparent magnitude of 2.91. has proper name of sadalsuud. having cooled , swollen around 50 times sun s diameter, around 2200 times luminous sun. around 6.4 times massive sun , around 56 million years old. sadalsuud 540 ± 20 light-years earth. alpha aquarii, known sadalmelik, has apparent magnitude of 2.94. 520 ± 20 light-years distant earth, , around 6.5 times massive sun , 3000 times luminous. 53 million years old.

gamma aquarii, called sadachbia, white main sequence star of spectral type star of spectral type a0v between 158 , 315 million years old , around 2 , half times sun s mass, , double radius. of magnitude 3.85, 164 ± 9 light years away. has luminosity of 50 l☉. name sadachbia comes arabic lucky stars of tents , sa d al-akhbiya.

δ aquarii, known scheat or skat, blue-white a2 spectral type star of magnitude 3.27 , luminosity of 105 l☉.

ε aquarii, known albali, blue-white a1 spectral type star apparent magnitude of 3.77, absolute magnitude of 1.2, , luminosity of 28 l☉.

ζ aquarii f2 spectral type double star; both stars white. overall, appears of magnitude 3.6 , luminosity of 50 l☉. primary has magnitude of 4.53 , secondary magnitude of 4.31, both have absolute magnitude of 0.6. orbital period 760 years; 2 components moving farther apart.

θ aquarii, called ancha, g8 spectral type star apparent magnitude of 4.16 , absolute magnitude of 1.4.

λ aquarii, called hudoor or ekchusis, m2 spectral type star of magnitude 3.74 , luminosity of 120 l☉.

ξ aquarii, called bunda, a7 spectral type star apparent magnitude of 4.69 , absolute magnitude of 2.4.

π aquarii, called seat, b0 spectral type star apparent magnitude of 4.66 , absolute magnitude of -4.1.

planetary systems

twelve exoplanet systems have been found in aquarius of 2013. gliese 876, 1 of nearest stars earth @ distance of 15 light-years, first red dwarf star found possess planetary system. orbited 4 planets, including 1 terrestrial planet 6.6 times mass of earth. planets vary in orbital period 2 days 124 days. 91 aquarii orange giant star orbited 1 planet, 91 aquarii b. planet s mass 2.9 times mass of jupiter, , orbital period 182 days. gliese 849 red dwarf star orbited first known long-period jupiter-like planet, gliese 849 b. planet s mass 0.99 times of jupiter , orbital period 1,852 days.

there less-prominent systems in aquarius. wasp-6, type g8 star of magnitude 12.4, host 1 exoplanet, wasp-6 b. star 307 parsecs earth , has mass of 0.888 solar masses , radius of 0.87 solar radii. wasp-6 b discovered in 2008 transit method. orbits parent star every 3.36 days @ distance of 0.042 astronomical units (au). 0.503 jupiter masses has proportionally larger radius of 1.224 jupiter radii. hd 206610, k0 star located 194 parsecs earth, host 1 planet, hd 206610 b. host star larger sun; more massive @ 1.56 solar masses , larger @ 6.1 solar radii. planet discovered radial velocity method in 2010 , has mass of 2.2 jupiter masses. orbits every 610 days @ distance of 1.68 au. closer sun wasp-47 b, orbits every 4.15 days 0.052 au sun, yellow dwarf (g9v) wasp-47. wasp-47 close in size sun, having radius of 1.15 solar radii , mass closer @ 1.08 solar masses. wasp-47 b discovered in 2011 transit method, wasp-6 b. larger jupiter mass of 1.14 jupiter masses , radius of 1.15 jupiter masses.

there several more single-planet systems in aquarius. hd 210277, magnitude 6.63 yellow star located 21.29 parsecs earth, host 1 known planet: hd 210277 b. 1.23 jupiter mass planet orbits @ same distance earth orbits sun—1.1 au, though orbital period longer @ around 442 days. hd 210277 b discovered earlier of other planets in aquarius, detected radial velocity method in 1998. star orbits resembles sun beyond similar spectral class; has radius of 1.1 solar radii , mass of 1.09 solar masses. hd 212771 b, larger planet @ 2.3 jupiter masses, orbits host star hd 212771 @ distance of 1.22 au. star itself, barely below threshold of naked-eye visibility @ magnitude 7.6, g8iv (yellow subgiant) star located 131 parsecs earth. though has similar mass sun—1.15 solar masses—it less dense radius of 5 solar radii. lone planet discovered in 2010 radial velocity method, several other exoplanets in constellation.

as of 2013, there 2 known multiple-planet systems within bounds of aquarius: gliese 876 , hd 215152 systems. former quite prominent; latter has 2 planets , has host star farther away @ 21.5 parsecs. hd 215152 system consists of planets hd 215152 b , hd 215152 c orbiting k0-type, magnitude 8.13 sun. both discovered in 2011 radial velocity method, 2 tiny planets orbit close host star. hd 215152 c larger @ 0.0097 jupiter masses (still larger earth, weighs in @ 0.00315 jupiter masses); smaller sibling barely smaller @ 0.0087 jupiter masses. error in mass measurements (0.0032 , 0.0049 mj respectively) large enough make discrepancy statistically insignificant. hd 215152 c orbits further star hd 215152 b, 0.0852 au compared 0.0652.

on 23 february 2017, nasa announced ultracool dwarf star trappist-1 in aquarius has 7 earth-like rocky planets. of these, 3 in system s habitable zone, , may contain water. discovery of trappist-1 system seen astronomers significant step toward finding life beyond earth.

deep sky objects

the green bean galaxy j2240 lies in constellation of aquarius

because of position away galactic plane, majority of deep-sky objects in aquarius galaxies, globular clusters, , planetary nebulae. aquarius contains 3 deep sky objects in messier catalog: globular clusters messier 2, messier 72, , open cluster messier 73. 2 well-known planetary nebulae located in aquarius: saturn nebula (ngc 7009), southeast of μ aquarii; , famous helix nebula (ngc 7293), southwest of δ aquarii.

m2, catalogued ngc 7089, rich globular cluster located approximately 37,000 light-years earth. @ magnitude 6.5, viewable in small-aperture instruments, 100 mm aperture telescope needed resolve stars. m72, catalogued ngc 6981, small 9th magnitude globular cluster located approximately 56,000 light-years earth. m73, catalogued ngc 6994, open cluster highly disputed status.

aquarius home several planetary nebulae. ngc 7009, known saturn nebula, 8th magnitude planetary nebula located 3,000 light-years earth. given moniker 19th century astronomer lord rosse resemblance planet saturn in telescope; has faint protrusions on either side resemble saturn s rings. appears blue-green in telescope , has central star of magnitude 11.3. compared helix nebula, planetary nebula in aquarius, quite small. ngc 7293, known helix nebula, closest planetary nebula earth @ distance of 650 light-years. covers 0.25 square degrees, making largest planetary nebula seen earth. however, because large, viewable faint object, though has high integrated magnitude of 6.0.

one of visible galaxies in aquarius ngc 7727, of particular interest amateur astronomers wish discover or observe supernovae. spiral galaxy (type s), has integrated magnitude of 10.7 , 3 3 arcseconds. ngc 7252 tangle of stars resulting collision of 2 large galaxies , known atoms-for-peace galaxy because of resemblance cartoon atom.

meteor showers

there 3 major meteor showers radiants in aquarius: eta aquariids, delta aquariids, , iota aquariids.

the eta aquariids strongest meteor shower radiating aquarius. peaks between 5 , 6 may rate of approximately 35 meteors per hour. discovered chinese astronomers in 401, eta aquariids can seen coming water jar beginning on april 21 , late may 12. parent body of shower halley s comet, periodic comet. fireballs common shortly after peak, approximately between may 9 , may 11. normal meteors appear have yellow trails.

the delta aquariids double radiant meteor shower peaks first on 29 july , second on 6 august. first radiant located in south of constellation, while second radiant located in northern circlet of pisces asterism. southern radiant s peak rate 20 meteors per hour, while northern radiant s peak rate 10 meteors per hour.

the iota aquariids weak meteor shower peaks on 6 august, rate of approximately 8 meteors per hour.