8 Cygni

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

{{Starbox begin

| name=8 Cygni

}}

{{Starbox observe

| epoch=J2000

| constell=Cygnus

| ra={{RA|19|31|46.32184}}{{cite journal|title=Validation of the new Hipparcos reduction|url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL|author1=van Leeuwen, F.|display-authors=etal|journal=Astronomy and Astrophysics|volume=474|issue=2|pages=653–664|date=2007|arxiv=0708.1752|bibcode=2007A&A...474..653V|doi=10.1051/0004-6361:20078357|s2cid = 18759600}}

| dec={{DEC|+34|27|10.6874}}

| appmag_v=4.75

}}

{{Starbox character

| class=B3 IV{{citation | last=Lesh | first=Janet Rountree | title=The Kinematics of the Gould Belt: an Expanding Group? | journal=Astrophysical Journal Supplement | volume=17 | page=371 | date=December 1968 | doi=10.1086/190179 | bibcode=1968ApJS...17..371L | doi-access=free }}

| b-v=−0.155{{cite journal|author1=Mermilliod, J.-C.|title=Compilation of Eggen's UBV data, transformed to UBV (unpublished)|journal=Catalogue of Eggen's UBV Data|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1|date=1986|bibcode= 1986EgUBV........0M}}

| u-b=

}}

{{Starbox astrometry

| radial_v={{Val|−21.20|0.1}}{{cite journal|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|author=Gontcharov, G. A.|date=2006|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|bibcode=2006AstL...32..759G|doi=10.1134/S1063773706110065|arxiv=1606.08053|s2cid=119231169}}

| prop_mo_ra=1.16

| prop_mo_dec=−3.47

| parallax=3.79

| p_error=0.16

| parallax_footnote=

}}

{{Starbox detail

| source =

| mass = 6.40

| radius = 6.50

| luminosity = 2,512

| temperature = 16,100

| metal_fe = +0.25

| gravity = 3.62

| rotational_velocity = 15{{cite journal|doi=10.1086/340590|title=Rotational Velocities of B Stars|journal=The Astrophysical Journal|volume=573|pages=359–365|year=2002|last1=Abt|first1=Helmut A.|last2=Levato|first2=Hugo|last3=Grosso|first3=Monica|issue=1 |bibcode = 2002ApJ...573..359A |doi-access=free}}

| age_myr =

}}

{{Starbox catalog

| names=8 Cygni, BD+34°3590, HD 184171, HIP 96052, HR 7426, SAO 68447.

}}

{{Starbox reference

|Simbad=8+Cyg}}

{{Starbox end}}

8 Cygni is a single{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | postscript=. | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 }} star in the northern constellation of Cygnus. Based upon its parallax of 3.79 mas, it is approximately 860 light-years (260 parsecs) away from Earth. It is visible to the naked eye as a faint, bluish-white hued star with an apparent visual magnitude of about 4.7. The star is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.

This is an aging subgiant star, as indicated by its spectral type of B3IV. Its effective temperature of 16,100 K fits into the normal range of B-type stars: 11,000 to 25,000 K. 8 Cygni is about twice as hot as the Sun, and it is six times larger and many times brighter in comparison.{{citation

| display-authors=1 | last1=Challouf | first1=M.

| last2=Nardetto | first2=N. | last3=Mourard | first3=D.

| last4=Graczyk | first4=D. | last5=Aroui | first5=H.

| last6=Chesneau | first6=O. | last7=Delaa | first7=O.

| last8=Pietrzyński | first8=G. | last9=Gieren | first9=W.

| last10=Ligi | first10=R. | last11=Meilland | first11=A.

| last12=Perraut | first12=K. | last13=Tallon-Bosc | first13=I.

| last14=McAlister | first14=H. | last15=Ten Brummelaar | first15=T.

| last16=Sturmann | first16=J. | last17=Sturmann | first17=L.

| last18=Turner | first18=N. | last19=Farrington | first19=C.

| last20=Vargas | first20=N. | last21=Scott | first21=N.

| title=Improving the surface brightness-color relation for early-type stars using optical interferometry⋆

| journal=Astronomy & Astrophysics | postscript=.

| volume=570 | pages=A104 | year=2014 | arxiv=1409.1351

| doi=10.1051/0004-6361/201423772 | bibcode=2014A&A...570A.104C | s2cid=14624307 }} The elemental abundances are near solar.{{cite journal | title=Elemental abundance analyses with DAO spectrograms - XIX. The superficially normal B stars zeta Draconis, epsilon Lyrae, 8 Cygni and 22 Cygni | last1=Adelman | first1=Saul J. | journal=Monthly Notices of the Royal Astronomical Society | volume=296 | issue=4 | pages=856–862 | date=June 1998 | doi=10.1046/j.1365-8711.1998.01426.x | bibcode=1998MNRAS.296..856A | doi-access=free }}