| 词条 | Zeta2 Lyrae |
| 释义 |
| name=Zeta2 Lyrae }}{{Starbox observe | epoch=J2000 | ra={{RA|18|44|48.20367}}[1] | dec={{DEC|+37|35|40.6162}}[1] | appmag_v=5.74[1] | constell=Lyra }}{{Starbox character | class=F0 IVn[2] | b-v=+0.29[1] | u-b=+0.06[1] | variable= }}{{Starbox astrometry | radial_v={{Val|−25.0|3.7}}[3] | prop_mo_ra={{Val|+18.70|0.21}}[1] | prop_mo_dec={{Val|+20.98|0.29}}[1] | parallax=20.97 | p_error=0.24 | parallax_footnote=[4] | absmag_v=+2.34[5] }}{{Starbox detail | mass=1.74[12] | radius= | luminosity= 9[6] | temperature= 7,000[6] | metal_fe= | gravity=3.94[12] | rotational_velocity=212[7] | age_gyr=1.223[8] }}{{Starbox catalog | names={{odlist | B=ζ2 Lyr | F=7 Lyr | BD=+37° 3223 | HD=173649 | HIP=91973 | HR=7057 | SAO=67324 | GC=25678 | WDS=J18448+3736D }}[9] }}{{Starbox reference | Simbad=7+Lyr}}{{Starbox end}}Zeta2 Lyrae is a single,[10] white-hued star in the northern constellation of Lyra. It is a dim star that is just visible to the naked eye with an apparent visual magnitude of 5.74[1] An annual parallax shift of 20.97 mas as seen from Earth provides a distance estimate of about 156 light years from the Sun. It is moving closer to the Sun with a radial velocity of −25 km/s.[3] This star has a stellar classification of F0 IVn,[2] suggesting it is an F-type subgiant star that is evolving away from the main sequence as its supply of hydrogen at the core has been consumed. The n suffix indicates "nebulous" lines caused by its rotation. It is spinning rapidly with a projected rotational velocity of 212 km/s.[7] This is giving the star an oblate shape with an equatorial bulge that is an estimated 29% larger than the polar radius.[11] The star is radiating approximately 9 times the Sun's luminosity from the photosphere at an effective temperature of 7,000 K.[6] It has 1.7[8] times the mass of the Sun and is about 1.2[8] billion years old. It is a suspected variable.[9] References1. ^1 2 3 {{citation | postscript=. | title=The galactic distribution of interstellar absorption as determined from the Celescope catalog of ultraviolet stellar observations and a new catalogue of UBV, Hbeta photoelectric observations | display-authors=1 | last1=Deutschman | first1=W. A. | last2=Davis | first2=R. J. | last3=Schild | first3=R. E. | journal=Astrophysical Journal Supplement Series | volume=30 | pages=97–225 | date=February 1976 | doi=10.1086/190359 | bibcode=1976ApJS...30...97D }} {{Stars of Lyra}}2. ^1 {{citation | display-authors=1 | last1=Cowley | first1=A. | last2=Cowley | first2=C. | last3=Jaschek | first3=M. | last4=Jaschek | first4=C. | title=A study of the bright A stars. I. A catalogue of spectral classifications | journal=Astronomical Journal | volume=74 | pages=375–406 |date=April 1969 | doi=10.1086/110819 | bibcode=1969AJ.....74..375C }} 3. ^1 {{citation | display-authors=1 | last1=Kharchenko | first1=N. V. | last2=Scholz | first2=R.-D. | last3=Piskunov | first3=A. E. | last4=Röser | first4=S. | last5=Schilbach | first5=E. | title=Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations | journal=Astronomische Nachrichten | volume=328 | issue=9 | pages=889–896 | year=2007 | bibcode=2007AN....328..889K | doi=10.1002/asna.200710776 | arxiv=0705.0878 | postscript=. }} 4. ^1 2 3 4 {{citation | first=F. | last=van Leeuwen | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=November 2007 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | arxiv=0708.1752 | postscript=. }} 5. ^{{citation | title=XHIP: An extended hipparcos compilation | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | postscript=. }} 6. ^1 2 {{cite journal | display-authors=1 | last=McDonald | first1=I. | last2=Zijlstra | first2=A. A. | last3=Boyer | first3=M. L. | date=2012 | title=Fundamental Parameters and Infrared Excesses of Hipparcos Stars | journal=Monthly Notices of the Royal Astronomical Society | volume=427 | issue=1 | pages=343–57 | bibcode=2012MNRAS.427..343M | arxiv=1208.2037 | doi=10.1111/j.1365-2966.2012.21873.x }} 7. ^1 {{citation | last1=Royer | first1=F. | last2=Zorec | first2=J. | last3=Gómez | first3=A. E. | title=Rotational velocities of A-type stars. III. Velocity distributions | journal=Astronomy and Astrophysics | volume=463 | issue= 2 | pages=671–682 |date=February 2007 | doi=10.1051/0004-6361:20065224 | bibcode=2007A&A...463..671R | arxiv=astro-ph/0610785 | postscript=. }} 8. ^1 2 3 4 {{cite journal | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. }} Vizier catalog entry 9. ^1 {{cite simbad|title=zet02 Lyr|accessdate=25 July 2015}} 10. ^{{cite journal | bibcode=2014MNRAS.437.1216D | title=The VAST Survey - III. The multiplicity of A-type stars within 75 pc | journal=Monthly Notices of the Royal Astronomical Society | volume=437 | issue=2 | page=1216 | display-authors=1 | last1=De Rosa | first1=R. J. | last2=Patience | first2=J. | last3=Wilson | first3=P. A. | last4=Schneider | first4=A. | last5=Wiktorowicz | first5=S. J. | last6=Vigan | first6=A. | last7=Marois | first7=C. | last8=Song | first8=I. | last9=MacIntosh | first9=B. | last10=Graham | first10=J. R. | last11=Doyon | first11=R. | last12=Bessell | first12=M. S. | last13=Thomas | first13=S. | last14=Lai | first14=O. | year=2014 | doi=10.1093/mnras/stt1932 | arxiv=1311.7141 }} 11. ^{{Cite journal | doi=10.1007/s00159-012-0051-2 | title=Interferometric observations of rapidly rotating stars | year=2012 | last1=Belle | first1=G. T. | journal=The Astronomy and Astrophysics Review | volume=20 | pages=51 | bibcode=2012A&ARv..20...51V | arxiv=1204.2572 }} 8 : F-type subgiants|Lyra (constellation)|Bayer objects|Durchmusterung objects|Flamsteed objects|Henry Draper Catalogue objects|Hipparcos objects|HR objects |
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