| 词条 | NN Serpentis |
| 释义 |
| name = NN Serpentis }}{{Starbox image | image = | caption = Rendering of NN Serpentis system }}{{Starbox observe | epoch = J2000 | constell = Serpens | ra = {{RA|15|52|56.131}}[1] | dec = {{DEC|+12|54|44.68}}[1] | appmag_v = +16.51[2] }}{{Starbox character | class = DAO1 / M4V[4] }}{{Starbox astrometry | dist_ly = 1670 ± 140 | dist_pc = 512 ± 43[4] }}{{Starbox orbit | reference = [4] | period_unitless = 0.13008017141(17) d | axis_unitless = {{solar radius|0.934 ± 0.009}} | eccentricity = 0.0 | inclination = 89.6 ± 0.2 | k1 = 62.3 ± 1.9 | k2 = 301 ± 3 }}{{Starbox detail | source = [4] | component1 = White dwarf | mass = 0.535 ± 0.012 | radius = 0.0211 ± 0.0002 | temperature = 57000 ± 3000 | gravity = 7.47 ± 0.01 | component2 = Red dwarf | mass2 = 0.111 ± 0.004 | radius2 = 0.149 ± 0.002 }}{{Starbox catalog | names = NN Ser, PG 1550+131, WD 1550+130 }}{{Starbox reference | Simbad = NN+Ser }}{{Starbox end}}NN Serpentis (abbreviated NN Ser) is an eclipsing post-common envelope binary system approximately 1670 light-years away.[4] The system comprises an eclipsing white dwarf and red dwarf. The two stars orbit each other every 0.13 days.[3] Planetary systemA planetary system has been inferred to exist around NN Ser by several teams. All of these teams rely on the fact that Earth sits in the same plane as the NN Serpentis binary star system, so humans can see the larger red dwarf eclipse the white dwarf every 0.13 days. Astronomers are then able to use these frequent eclipses to spot a pattern of small but significant irregularities in the orbit of stars, which could be attributed to the presence and gravitational influence of circumbinary planets. Chen (2009) used these "eclipse timing variations" to suggesting a putative orbital period spanning between 30 and 285 years and a minimum mass between 0.0043 and 0.18 Solar masses.[4] In late 2009, Qian [5] estimated a minimum mass of 10.7 Jupiter masses and orbital period of 7.56 years for this planet, probably located at 3.29 Astronomical Units. This has since been disproven by further measurements of the eclipse times of the binary stars.[6] In late 2009 and 2010, researchers from the UK (University of Warwick and the University of Sheffield), Germany (Georg-August-Universitat in Göttingen, Eberhard-Karls-Universitat in Tübingen), Chile (Universidad de Valparaíso), and the United States (University of Texas at Austin).[7] suggested that the eclipse timing variations are caused by two gas giant planets. The more massive gas giant is about 6 times the mass of Jupiter and orbits the binary star every 15.5 years, the other orbits every 7.75 years and is about 1.6 times the mass of Jupiter. {{OrbitboxPlanet begin| table_ref=[8] | period_unit=day }}{{OrbitboxPlanet | exoplanet = c | mass = 6.91 ± 0.54 | period = 5660 ± 165 days | semimajor = 5.38 ± 0.2 | eccentricity = 0 }}{{OrbitboxPlanet | exoplanet = b | mass = 2.28 ± 0.38 | period = 2830 ± 130 days | semimajor = 3.39 ± 0.1 AU | eccentricity = 0.2 ± 0.02 }}{{Orbitbox end}} See also
References1. ^1 {{cite journal|title=2MASS All-Sky Catalog of Point Sources|date=2003|journal=VizieR On-line Data Catalog|volume=2246|author=Cutri, R. M.|display-authors=etal|bibcode=2003yCat.2246....0C}} 2. ^{{cite journal|bibcode=2014ApJS..213....9D|doi=10.1088/0067-0049/213/1/9|arxiv=1405.4290|title=The Catalina Surveys Periodic Variable Star Catalog|journal=The Astrophysical Journal Supplement Series|volume=213|pages=9|year=2014|last1=Drake|first1=A. J.|last2=Graham|first2=M. J.|last3=Djorgovski|first3=S. G.|last4=Catelan|first4=M.|last5=Mahabal|first5=A. A.|last6=Torrealba|first6=G.|last7=García-Álvarez|first7=D.|last8=Donalek|first8=C.|last9=Prieto|first9=J. L.|last10=Williams|first10=R.|last11=Larson|first11=S.|last12=Christen Sen|first12=E.|last13=Belokurov|first13=V.|last14=Koposov|first14=S. E.|last15=Beshore|first15=E.|last16=Boattini|first16=A.|last17=Gibbs|first17=A.|last18=Hill|first18=R.|last19=Kowalski|first19=R.|last20=Johnson|first20=J.|last21=Shelly|first21=F.}} 3. ^1 2 3 4 5 {{cite journal|title=Precise mass and radius values for the white dwarf and low mass M dwarf in the pre-cataclysmic binary NN Serpentis|author1=Parsons, S. G.|author2=Marsh, T. R.|author3=Copperwheat, C. M.|author4=Dhillon, V. S.|author5=Littlefair, S. P.|author6=Gänsicke, B. T.|author7=Hickman, R.|journal=Monthly Notices of the Royal Astronomical Society|volume=402|issue=4|pages=2591–2608|date=2010|bibcode=2010MNRAS.402.2591P|arxiv=0909.4307|doi=10.1111/j.1365-2966.2009.16072.x}} 4. ^{{cite journal | arxiv=0904.2319 | author=Chen | title=Can angular momentum loss cause the period change of NN Ser? | date=2009 | bibcode=2009A&A...499L...1C|doi = 10.1051/0004-6361/200911638 | volume=499 | journal=Astronomy and Astrophysics | pages=L1–L3}} 5. ^{{cite journal | url=http://www.iop.org/EJ/abstract/1538-4357/706/1/L96/ | author=Qian | title=A SUBSTELLAR COMPANION TO THE WHITE DWARF-RED DWARF ECLIPSING BINARY NN Ser | date=2009}} 6. ^{{cite journal | arxiv=1005.3958 | author=Parsons | title=Orbital Period Variations in Eclipsing Post Common Envelope Binaries | date=2010|display-authors=etal | doi=10.1111/j.1365-2966.2010.17063.x | volume=407 | journal=Monthly Notices of the Royal Astronomical Society | pages=2362–2382 | bibcode=2010MNRAS.407.2362P}} 7. ^{{cite journal |title=Two planets orbiting the recently formed post-common envelope binary NN Serpentis |author=K. Beuermann |displayauthors=etal |journal=Astronomy & Astrophysics |volume=521 |date=October 2010 |url=https://www.aanda.org/articles/aa/abs/2010/13/aa15472-10/aa15472-10.html |doi=10.1051/0004-6361/201015472|arxiv=1010.3608 |bibcode=2010A&A...521L..60B }} 8. ^{{cite web|url=http://www.exoplanet.eu/planet.php?p1=NN+Ser+%28ab%29&p2=c|title=Notes for star NN Ser|author=Schneider, J|work=The Extrasolar Planets Encyclopaedia|accessdate=2010-10-22|deadurl=yes|archiveurl=https://web.archive.org/web/20101015235041/http://exoplanet.eu//planet.php?p1=NN+Ser+(ab)&p2=c|archivedate=2010-10-15|df=}} External links
6 : Eclipsing binaries|Objects with variable star designations|White dwarfs|M-type main-sequence stars|Circumbinary planets|Multi-star planetary systems |
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