zeta2 Lyrae

{{short description|Star in the constellation Lyra}}

{{DISPLAYTITLE:Zeta² Lyrae}}

{{other stars by Bayer designation|Zeta Lyrae{{!}}ζ Lyrae}}

{{Starbox begin

| name=Zeta² Lyrae

}}

{{Starbox observe

| epoch = J2000

| ra = {{RA|18|44|48.19919}}

| dec = {{DEC|+37|35|40.5585}}

| appmag_v = 5.74{{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 | doi-access=free }}

| constell = Lyra

}}

{{Starbox character

| class = F0 IVn{{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 }} or F1Vnn{{citation | title=The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars | journal=The Astronomical Journal | volume=121 | issue=4 | pages=2148 | year=2001 | last1=Gray | first1=R. O. | last2=Napier | first2=M. G. | last3=Winkler | first3=L. I. | bibcode=2001AJ....121.2148G | doi=10.1086/319956 | doi-access=free | postscript=. }}

| b-v = +0.29

| u-b = +0.06

| variable =

}}

{{Starbox astrometry

| radial_v = {{Val|−25.0|3.7}}{{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 | s2cid=119323941 | postscript=. }}

| prop_mo_ra = +23.969

| prop_mo_dec = +23.461

| parallax = 20.6386

| p_error = 0.0443

| parallax_footnote = {{cite Gaia DR3|2096869455581362560}}

| absmag_v = +2.34{{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 | s2cid=119257644 | postscript=. }}

}}

{{Starbox detail

| mass = 1.74

| radius = {{val|2.03|0.02}}

| luminosity = {{val|9.5|0.1}}

| temperature = {{val|7257|37|3|fmt=commas}}

| metal_fe = −0.36

| gravity = 3.94

| rotational_velocity = 212{{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 | s2cid=18475298 | postscript=. }}

| age_gyr = 1.223{{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. | s2cid=33401607 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/ApJ/804/146/table5&HIP=12876 Vizier catalog entry]

}}

{{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 }}{{cite simbad|title=zet02 Lyr|access-date=25 July 2015}}

}}

{{Starbox reference

| Simbad=7+Lyr

}}

{{Starbox end}}

File:Zeta Lyrae.jpg and ζ² Lyrae photographed by amateur astronomer David Chifiriuc in 2020. The separation between the two stars is {{val|43.7|ul="}}.]]

Zeta² Lyrae is a single,{{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 | doi-access=free | arxiv=1311.7141 }} 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 An annual parallax shift of {{val|20.6|ul=mas}} as seen from Earth provides a distance estimate of about 158 light years from the Sun. It is moving closer to the Sun with a radial velocity of −25 km/s.

This star has a stellar classification of F0 IVn, 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. This is giving the star an oblate shape with an equatorial bulge that is an estimated 29% larger than the polar radius.{{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 | issue=1 | pages=51 | bibcode=2012A&ARv..20...51V | arxiv=1204.2572 | s2cid=119273474 }} The star is radiating approximately 9.6 times the Sun's luminosity from the photosphere at an effective temperature of about {{val|7,000|ul=K|fmt=commas}}. It has 1.7 times the mass of the Sun, twice the Sun's radius, and is about 1.2 billion years old.

It is a suspected variable.

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