{{Short description|Star in the constellation Hydra}} {{about-distinguish2|l Hydrae|[[I Hydrae]], [[Iota Hydrae|ι (iota) Hydrae]], or [[Lambda Hydrae|λ (lambda) Hydrae]]}} {{Starbox begin}} {{Starbox observe | epoch = J2000 | constell = [[Hydra (constellation)|Hydra]] | ra = {{RA|14|28|10.42638}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−29|29|29.8884}}<ref name=vanLeeuwen2007/> | appmag_v = 4.97<ref name=Anderson2012/> {{nowrap|(5.70 + 5.70 + 10.00)}}<ref name=WDSC2014/> }} {{Starbox character | type = main sequence<ref name=zorec2012/> | class = B7/8V<ref name=houk1979/> | b-v = {{Val|−0.074|0.003}}<ref name=Anderson2012/> | u-b = | variable = }} {{Starbox astrometry | radial_v = {{Val|5.4|3.8}}<ref name=Anderson2012/> | prop_mo_ra = −25.23<ref name=vanLeeuwen2007/> | prop_mo_dec = −23.03<ref name=vanLeeuwen2007/> | parallax = 8.29 | p_error = 0.28 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = −0.43<ref name=Anderson2012/> }} {{Starbox detail | source = | component1 = 52 Hya A | mass = {{Val|3.82|0.06}}<ref name=zorec2012/> | radius = | luminosity = {{Val|310.5|24.5|22.8}}<ref name=zorec2012/> | temperature = {{Val|12853|89|fmt=commas}}<ref name=zorec2012/> | metal_fe = | gravity = | rotational_velocity = 204<ref name=zorec2012/> | rotation = | age_gyr = }} {{Starbox catalog | names = {{odlist | B=l Hya | F=52 Hya | CD=−28°10712 | FK5=532 | HD=126769 | HIP=70753 | HR=5407 | SAO=182570 | ADS=9270 | WDS=J14282-2929 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad=l+Hya }} {{Starbox end}}

'''52 Hydrae''' is a [[triple star system]]<ref name=Eggleton2008/> in the [[constellation]] [[Hydra (constellation)|Hydra]]. It has the [[Bayer designation]] '''l Hydrae'''; ''52 Hydrae'' is the [[Flamsteed designation]].<ref name=SIMBAD/> This system is visible to the naked eye as a faint, blue-white hued star with an [[apparent visual magnitude]] of 4.97.<ref name=Anderson2012/> It is a probable (80% chance) member of the [[Sco OB2]] [[moving group]] of stars,<ref name=Rizzuto2011/> and is moving away from the Earth with a heliocentric [[radial velocity]] of 5&nbsp;km/s.<ref name=Anderson2012/>

The primary component is a binary system<ref name=Eggleton2008/> consisting of two nearly equal components with an [[orbital period]] of around {{convert|5495|days|years|0|disp=out|abbr=off}}<ref name=Tokovinin2008/> and an [[angular separation]] of {{Val|0.1|ul=arcsecond}}.<ref name=Eggleton2008/> It shows a combined [[stellar classification]] of B7/8V,<ref name=houk1979/> which matches a [[B-type main-sequence star]]. The third component is a magnitude 10.0 star at a separation of {{Val|4.2|u=arcsecond}}<ref name=Eggleton2008/> with a mass similar to the Sun. It is orbiting the inner pair with a period of around {{Convert|1410000|days|years|disp=out|abbr=off}}.<ref name=Tokovinin2008/>

==References== <references> <ref name=SIMBAD>{{cite simbad | title=l Hya | access-date=May 5, 2019 }}</ref>

<ref name=Anderson2012>{{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | postscript=. | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

<ref name=vanLeeuwen2007>{{citation | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}</ref>

<ref name=Eggleton2008>{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | postscript=. | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 }}</ref>

<ref name=zorec2012>{{citation | last1=Zorec | first1=J. | last2=Royer | first2=F. | title=Rotational velocities of A-type stars. IV. Evolution of rotational velocities | journal=Astronomy & Astrophysics | volume=537 | pages=A120 | year=2012 | doi=10.1051/0004-6361/201117691 | postscript=. | bibcode=2012A&A...537A.120Z | arxiv=1201.2052 | s2cid=55586789 }}</ref>

<ref name=houk1979>{{citation | last1=Houk | first1=Nancy | title=Michigan catalogue of two-dimensional spectral types for the HD stars | volume=3 | date=1979 | postscript=. | publication-place=Ann Arbor, Michigan | publisher=Dept. of Astronomy, University of Michigan | bibcode=1982mcts.book.....H }}</ref>

<ref name=Rizzuto2011>{{citation | display-authors=1 | last1=Rizzuto | first1=Aaron | last2=Ireland| first2=Michael | last3=Robertson | first3=J. G. | title=Multidimensional Bayesian membership analysis of the Sco OB2 moving group | journal=Monthly Notices of the Royal Astronomical Society | date=October 2011 | volume=416 | issue=4 | pages=3108–3117 | bibcode=2011MNRAS.416.3108R | arxiv=1106.2857 | doi=10.1111/j.1365-2966.2011.19256.x | doi-access=free | s2cid=54510608 | postscript=. }}</ref>

<ref name=Tokovinin2008>{{citation | title=Comparative statistics and origin of triple and quadruple stars | last1=Tokovinin | first1=A. | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=925–938 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13613.x | doi-access=free | postscript=. | bibcode=2008MNRAS.389..925T | arxiv=0806.3263 | s2cid=16452670 }}</ref>

<ref name=WDSC2014>{{citation | display-authors=1 | last1=Mason | first1=B. D. | last2=Wycoff | first2=G. L. | last3=Hartkopf | first3=W. I. | last4=Douglass | first4=G. G. | last5=Worley | first5=C. E. | title=The Washington Visual Double Star Catalog | journal=The Astronomical Journal | year=2014 | volume=122 | issue=6 | page=3466 | bibcode=2001AJ....122.3466M | doi=10.1086/323920 | url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds | access-date=2015-07-22 | postscript=. | doi-access=free }}</ref> </references>

{{Stars of Hydra}}

[[Category:B-type main-sequence stars]] [[Category:Triple stars]] [[Category:Hydra (constellation)]] [[Category:Bayer objects|Hydrae, l]] [[Category:Durchmusterung objects]] [[Category:Flamsteed objects|Hydrae, 52]] [[Category:Henry Draper Catalogue objects|126769]] [[Category:Hipparcos objects|070753]] [[Category:Bright Star Catalogue objects|5407]]