| 词条 | 55 Cancri f |
| 释义 |
| name = 55 Cancri f | symbol = | image = Artist's concept shows four of the five planets that orbit 55 Cancri, a star much like our own.jpg | image_size = | image_alt = | caption = An artist's impression of 55 Cancri f. The three bright dots near its star are the three innermost planets. | background = | bgcolour = | label_width = | discoverer = announced by J. Wisdom published by D. Fischer | discovery_site = {{flag|United States}} | discovered = 11 April 2005 (announced) 6 November 2007 (published) | discovery_method = Doppler spectroscopy | discovery_ref = | exosolar planets = | minorplanet = | 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 = {{convert|0.833|AU|km|abbr=on}} | perihelion = {{convert|0.730|AU|km|abbr=on}} | semimajor = {{convert|0.781|±|0.007|AU|km|abbr=on}}[1] | mean_orbit_radius = | eccentricity = 0.2 ± 0.2[1] | period = 260.00 ± 1.1[1] d 0.7118 y | synodic_period = | avg_speed = | mean_anomaly = | mean_motion = | inclination = | angular_dist = | asc_node = | long_periastron = | time_periastron = 2,450,080.9108 ± 1.1[1] | arg_peri = 181.1 ± 60[1] | semi-amplitude = 4.879 ± 0.6[1] | satellite_of = | satellites = | star = 55 Cancri A | 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 = {{convert|200–300|K|C F}} | spectral_type = | magnitude = | abs_magnitude = | angular_size = | family = | atmosphere_ref = | atmosphere = | scale_height = | surface_pressure = | atmosphere_composition = | note = }}55 Cancri f (abbreviated 55 Cnc f), also designated Rho1 Cancri f and named Harriot, is an extrasolar planet approximately 41 light-years away from Earth in the constellation of Cancer (the Crab). 55 Cancri f is the fourth known planet (in order of distance) from the star 55 Cancri and the first planet to have been given the designation of "f".[2] In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars.[3] The process involved public nomination and voting for the new names.[4] In December 2015, the IAU announced the winning name was Harriot for this planet.[5] The winning name was submitted by the Royal Netherlands Association for Meteorology and Astronomy of the Netherlands. It honors the astronomer Thomas Harriot.[6] DiscoveryThe initial presentation of this planet occurred at a meeting of the American Astronomical Society in April 2005,[7] however it was another two and a half years before the planet was to be published in a peer-reviewed journal.[1] It is the first known planet outside our solar system to spend its entire orbit within what astronomers call the "habitable zone".[8] Furthermore, its discovery made 55 Cancri the first star other than the Sun known to have at least five planets. Orbit and mass55 Cancri f is located about 0.781 AU away from the star and takes 262 days to complete a full orbit.[9] A limitation of the radial velocity method used to detect 55 Cancri f is that only a minimum mass can be obtained, in this case around 0.144 times that of Jupiter, or half the mass of Saturn.[9] A Keplerian fit to the radial velocity data of 55 Cancri A indicates that the orbit is consistent with being circular, however changing the value in a range between 0 and 0.4 does not significantly alter the chi-squared statistic of the fit, thus a representative eccentricity of 0.2±0.2 was assumed.[1] In a Newtonian model which takes interactions between the planets into account, the eccentricity comes out as 0.0002, almost perfectly circular.[1] Astrometric observations made with the Hubble Space Telescope suggest that the outer planet 55 Cancri d is inclined at 53° with respect to the plane of the sky.[10] The inner planets b and e are inclined at 85°. The inclination of f is unknown. CharacteristicsSince the planet was detected indirectly through observations of its star, properties such as its radius, composition and temperature are unknown. With a mass half that of Saturn,[9] 55 Cancri f is likely to be a gas giant with no solid surface. It orbits in the so-called "habitable zone," which means that liquid water could exist on the surface of a possible moon.[8] It is not known if the composition and appearance is more like that of Saturn or Neptune.[2] Based on its temperature, it should be a Sudarsky Class II planet, covered in water clouds.{{citation needed|date=May 2012}} References1. ^1 2 3 4 5 6 7 8 {{cite journal|arxiv=0712.3917 |journal= Astrophysical Journal |title=Five Planets Orbiting 55 Cancri| display-authors=6| author=Debra A. Fischer| author2=Geoffrey W. Marcy| author3=R. Paul Butler| author4=Steven S. Vogt| author5=Greg Laughlin| author6=Gregory W. Henry| author7=David Abouav| author8=Kathryn M. G. Peek| author9=Jason T. Wright| author10=John A. Johnson| author11=Chris McCarthy| author12=Howard Isaacson| date=23 December 2007|bibcode = 2008ApJ...675..790F |doi = 10.1086/525512|volume=675|pages=790–801 }} 2. ^1 {{cite web |url=http://astrobiology.nasa.gov/articles/researchers-identify-first-five-planet-extrasolar-system/ |title=Researchers Identify First Five-Planet Extrasolar System |publisher=NASA Astrobiology |date=12 November 2007 |author=Shige Abe |accessdate=17 September 2008 |archiveurl=https://web.archive.org/web/20080916211923/http://astrobiology.nasa.gov/articles/researchers-identify-first-five-planet-extrasolar-system/ |archivedate=16 September 2008 |deadurl=yes |df=dmy-all }} 3. ^NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars. IAU.org. 9 July 2014 4. ^NameExoWorlds The Process 5. ^Final Results of NameExoWorlds Public Vote Released, International Astronomical Union, 15 December 2015. 6. ^NameExoWorlds The Approved Names 7. ^{{cite journal |author=J. Wisdom |url=http://www.aas.org/publications/baas/v37n2/dda05/29.htm |archiveurl=https://web.archive.org/web/20061216012023/http://www.aas.org/publications/baas/v37n2/dda05/29.htm |archivedate=16 December 2006 |title=A Neptune-sized Planet in the rho1 Cancri System |accessdate=17 September 2008 |publisher=The American Astronomical Society |date=11 April 2005| journal=DDA 36th Meeting, 10–14 April 2005—Session 5 Posters}} 8. ^1 {{cite news|url=https://www.theguardian.com/science/2007/nov/07/spaceexploration |title=Could this be Earth's near twin? Introducing planet 55 Cancri f |publisher=The Guardian |author=Ian Sample, science correspondent |date= 7 November 2007|accessdate=17 October 2008 | location=London| archiveurl= https://web.archive.org/web/20081002080911/http://www.guardian.co.uk/science/2007/nov/07/spaceexploration| archivedate= 2 October 2008 | deadurl= no}} 9. ^1 2 {{cite web |url=http://exoplanet.eu/planet.php?p1=55+Cnc&p2=f |title=Notes for Planet 55 Cnc f |author=Jean Schneider |date=2011 |publisher=Extrasolar Planets Encyclopaedia |accessdate=8 October 2011}} 10. ^{{cite journal | author=Han | title=Preliminary Astrometric Masses for Proposed Extrasolar Planetary Companions | journal=The Astrophysical Journal Letters | volume=548 | issue=1 | pages=L57–L60 | date=2001 | doi=10.1086/318927 | last2=Black | first2=David C. | last3=Gatewood | first3=George|bibcode = 2001ApJ...548L..57H | display-authors=1 }} External links{{Wikipedia books|55 Cancri}}{{Commons category|55 Cancri f}}
6 : 55 Cancri|Cancer (constellation)|Exoplanets discovered in 2005|Exoplanets detected by radial velocity|Giant planets in the habitable zone|Exoplanets with proper names |
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