23 Librae b

{{Short description|Extrasolar planet in the constellation Libra}} {{Infobox planet | name = 23 Librae b | symbol = | image = Planet 23 Librae b.png | image_size = | image_alt = | caption = 23 Librae b (min. mass ~1.59 M<sub>J</sub>) as seen with Celestia | background = | bgcolour = | label_width =  | discovery_ref = <ref name="Keck"/><ref name="Vogt2000"/> | discoverer = [[California and Carnegie Planet Search|California and<br>Carnegie Planet Search]] | discovery_site = [[W. M. Keck Observatory]] | discovered = November 1, 1999 | discovery_method = [[Doppler spectroscopy]] | exosolar planets = | minorplanet = no | extrasolarplanet = | mpc_name = | pronounced = | named_after = | alt_names = | mp_category = | adjectives =  | orbit_ref = | orbit_diagram = | epoch = | uncertainty = | observation_arc = | earliest_precovery_date = | apsis = astron | aphelion = | perihelion = | semimajor = {{convert|0.81 ± 0.02|AU|e6km|abbr=unit}} | mean_orbit_radius = | eccentricity = 0.233 ± 0.002 | period = 258.19 ± 0.07 [[day|d]]<br>0.7069 [[year|y]] | synodic_period = | avg_speed = | mean_anomaly = | mean_motion = | inclination = | angular_dist = | asc_node = | long_periastron = | time_periastron = 2,450,331.7 ± 2.2 | arg_peri = 358.3 ± 3.7 | semi-amplitude = 49.52 ± 0.57 | satellite_of = | satellites = | star = [[23 Librae]] | allsatellites = | tisserand =  | physical_ref = | dimensions = | mean_diameter = | mean_radius = | equatorial_radius = | polar_radius = | flattening = | circumference = | surface_area = | volume = | mass = | density = | surface_grav = | moment_of_inertia_factor = | escape_velocity = | rotation = | sidereal_day = | rot_velocity = | axial_tilt = | right_asc_north_pole = | declination = | pole_ecliptic_lat = | pole_ecliptic_lon = | albedo = | single_temperature = | spectral_type = | magnitude = | abs_magnitude = | angular_size = | family =  | atmosphere_ref = | atmosphere = | scale_height = | surface_pressure = | atmosphere_composition =  | note = }} '''23 Librae b''' (23 Lib b), also known as HD 134987 b, is an [[Exoplanet|extrasolar]] [[Jovian planet]] discovered in November 1999 orbiting the star [[23 Librae]]. It orbits in its star's [[habitable zone]].<ref name="Keck"/><ref name="Vogt2000"/><ref name="Butler2006"/>

As of 1999, the planet was known to have at least 1.5 times [[Jupiter mass|Jupiter's mass]]. The planet orbits 23 Librae at an average distance of 0.82 [[Astronomical unit|AU]], which is between that of [[Venus]] and the [[Earth]] in the [[Solar System]].<ref name="Jones2010"/>

==See also== * [[List of exoplanets discovered before 2000]]

==References== {{Reflist|refs=

<ref name="Butler2006">{{cite journal | title=Catalog of Nearby Exoplanets | last1=Butler | first1=R. P. | last2=Wright | first2=J. T. | last3=Marcy | first3=G. W. | last4=Fischer | first4=D. A. | last5=Vogt | first5=S. S. | last6=Tinney | first6=C. G. | last7=Jones | first7=H. R. A. | last8=Carter | first8=B. D. | last9=Johnson | first9=J. A. | last10=McCarthy | first10=C. | last11=Penny | first11=A. J. | journal=The Astrophysical Journal | volume=646 | issue=1 | pages=505–522 | year=2006 | arxiv=astro-ph/0607493 | bibcode=2006ApJ...646..505B | bibcode-access=free | doi=10.1086/504701 | doi-access=free |author-link1=R. Paul Butler|author-link3=Geoffrey Marcy|author-link6=Chris Tinney|author-link5=Steven S. Vogt}}</ref>

<ref name="Jones2010">{{cite journal | title=A long-period planet orbiting a nearby Sun-like star | last1=Jones | first1=Hugh R. A. | last2=Butler | first2=R. Paul | last3=Tinney | first3=C. G. | last4=O'Toole | first4=Simon | last5=Wittenmyer | first5=Rob | last6=Henry | first6=Gregory W. | last7=Meschiari | first7=Stefano | last8=Vogt | first8=Steve | last9=Rivera | first9=Eugenio | last10=Laughlin | first10=Greg | last11=Carter | first11=Brad D. | last12=Bailey | first12=Jeremy | last13=Jenkins | first13=James S. | journal=Monthly Notices of the Royal Astronomical Society | volume=403 | issue=4 | pages=1703–1713 | year=2010 | arxiv=0912.2716 | bibcode=2010MNRAS.403.1703J | bibcode-access=free | doi=10.1111/j.1365-2966.2009.16232.x | doi-access=free |author-link3=Chris Tinney|author-link2=R. Paul Butler|author-link8=Steven S. Vogt|author-link10=Gregory P. Laughlin}}</ref>

<ref name="Keck">{{cite press release | title=Astronomers discover six new planets orbiting nearby stars | date=November 1, 1999 | publisher=W. M. Keck Observatory | location=Kamuela, HI | url=http://www.keckobservatory.org/astronomers_discover_six_new_planets_orbiting_nearby_stars/ | access-date=December 19, 2017 }}</ref>

<ref name="Vogt2000">{{cite journal | title=Six New Planets from the Keck Precision Velocity Survey | last1=Vogt | first1=Steven S. | last2=Marcy | first2=Geoffrey W. | last3=Butler | first3=R. Paul | last4=Apps | first4=Kevin | journal=The Astrophysical Journal | volume=536 | issue=2 | pages=902–914 | year=2000 | arxiv=astro-ph/9911506 | bibcode=2000ApJ...536..902V | bibcode-access=free | doi=10.1086/308981 | doi-access=free |author-link1=Steven S. Vogt|author-link3=R. Paul Butler|author-link2=Geoffrey Marcy}}</ref>

}}

{{DEFAULTSORT:23 Librae b}} [[Category:Libra (constellation)]] [[Category:Exoplanets detected by radial velocity]] [[Category:Exoplanets discovered in 1999]] [[Category:Giant planets in the habitable zone]]