Phi Cygni

{{Starbox begin

| name = φ Cygni

}}

{{Starbox image

| image=

{{Location mark

|image=Cygnus constellation map.svg|alt=|float=center|width=280

|label=|position=right

|mark=Red circle.svg|mark_width=8|mark_link=φ Cyg

|x=586|y=650

}}

|caption=Location of φ Cygni (circled)

}}

{{Starbox observe

| epoch = J2000

| constell = Cygnus

| ra = {{RA|19|39|22.60591}}

| dec = {{DEC|+30|09|11.9604}}

| appmag_v = 4.70 {{nowrap|(5.31 + 5.6)}}

}}

{{Starbox character

| type = red clump

| class = G8III + G8III

| b-v = +0.98

| u-b = +0.81

}}

{{Starbox astrometry

| radial_v = +4.50

| prop_mo_ra = +2.48

| prop_mo_dec = +36.50

| pm_footnote =

| parallax = 14.9244

| p_error = 0.4176

| parallax_footnote =

| absmag_v = +0.12 {{nowrap|(+0.77/+1.07)}}

}}

{{Starbox orbit

| reference =

| period =

| period_unitless = 434.208 days

| axis = 26.9 mas

| axis_unitless =

| eccentricity = 0.5557

| inclination = 80.8

| node = 251

| periastron = 2451239.58

| periarg = 209.41

| k1 = 26.40

| k2 = 27.22

}}

{{Starbox detail

| source =

| component1 = A

| mass = {{val|2.104|0.049}}

| radius = {{solar radius calculator|type=logLT|1.54|5129|decimals=2}}{{efn|name=radius1}}

| temperature = {{val|5130|120|fmt=commas}}

| luminosity = {{val|34.7|2.5|2.3}}

| rotational_velocity = 4.7

| age_myr = {{val|479|58|52}}

| component2 = B

| mass2 = {{val|2.040|0.042}}

| radius2 = {{solar radius calculator|type=logLT|1.45|2=5011.87|decimals=2}}{{efn|name=radius2}}

| temperature2 = {{val|5010|fmt=commas}}

| luminosity2 = {{val|28|3}}

| rotational_velocity2 = 4.8

| metal_fe = −0.11

| age_myr2 = {{val|562|69|61}}

}}

{{Starbox catalog

| names = {{odlist | B=φ Cygni | F=12 Cygni | BD=+29°3684 | HD=185734 | HIP=96683 | HR=7478 | SAO=68637 | GC=27203 | WDS=J19394+3009AB}}

}}

{{Starbox reference

| Simbad = phi+Cygni

}}

Phi Cygni, Latinized from φ Cygni, is a binary star system in the northern constellation of Cygnus. It is faintly visible to the naked eye with an apparent visual magnitude of 4.70. The annual parallax shift is 14.92 mas as measured from Earth, which yields a distance estimate of around 220 light years. It is moving further from the Sun with a radial velocity of +4.5 km/s.

φ Cygni is a double-lined spectroscopic binary system, which means that the absorption lines of both components are visible in the spectrum. The two sets of spectral lines are almost identical and both stars are assigned a spectral type of K0III, meaning they have evolved into giants. They are considered to be red clump giants, stars that have begun core helium fusion and lie on the horizontal branch but because of their metallicity and the size of their hydrogen envelope they are found very close to the red giant branch. The two stars are assumed to have the same age, which would be around 650 million years. The pair have an orbital period of 434.208 days, or 1.2 Earth years, a semimajor axis of 26.9 mas, and a high eccentricity of 0.56.

Notes

{{Notelist|notes=

{{Efn|name=radius1|1=Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: $\sqrt{\biggl(\frac{5,772}{10^{3.71}}\biggr)^4 \cdot 10^{1.53}} = 7.46\ R_\odot.$ }}

{{Efn|name=radius2|1=Calculated, using the Stefan-Boltzmann law and the star's effective temperature and luminosity, with respect to the solar nominal effective temperature of 5,772 K: $\sqrt{\biggl(\frac{5,772}{10^{3.70}}\biggr)^4 \cdot 10^{1.45}} = 7.04\ R_\odot.$ }}

}}

References

{{reflist|refs=

{{cite journal|bibcode=2000A&AS..145..215P|title=Resolved double-lined spectroscopic binaries: A neglected source of hypothesis-free parallaxes and stellar masses|journal=Astronomy and Astrophysics Supplement|volume=145|issue=2|pages=215–222|last1=Pourbaix|first1=D|year=2000|doi=10.1051/aas:2000237|doi-access=free}}

{{cite journal|bibcode=2004RMxAC..21...63F|title=The Spectroscopic Orbit of φ Cygni, a System with Two Late-Type Giants|journal=The Environment and Evolution of Double and Multiple Stars|volume=21|pages=63|last1=Fekel|first1=F. C|year=2004}}

{{citation | display-authors=1 | last1=Pourbaix | first1=D. | last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H. | last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I. | last6=Levato | first6=H. | last7=Morrell | first7=N. I. | last8=Torres | first8=G. | last9=Udry | first9=S. | year=2004 | pages=727–732 | volume=424 | issue=2 | title=SB9: The Ninth Catalogue of Spectroscopic Binary Orbits | journal=Astronomy & Astrophysics | bibcode=2004A&A...424..727P | doi=10.1051/0004-6361:20041213 | postscript=. | arxiv=astro-ph/0406573 | s2cid=119387088 }}

{{cite journal|bibcode=2008AJ....135..209M|title=Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity|journal=The Astronomical Journal|volume=135|pages=209–231|last1=Massarotti|first1=Alessandro|last2=Latham|first2=David W|last3=Stefanik|first3=Robert P|last4=Fogel|first4=Jeffrey|year=2008|issue=1|doi=10.1088/0004-6256/135/1/209|doi-access=free}}

{{cite journal | title=Validation of the new Hipparcos reduction | url=http://www.aanda.org/articles/aa/full/2007/41/aa8357-07/aa8357-07.html | last1=van Leeuwen | first1=F. | 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 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HIP%2096683 Vizier catalog entry]

{{cite journal|bibcode=2008A&A...480...91S|title=Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants|journal=Astronomy and Astrophysics|volume=480|pages=91–101|last1=Soubiran|first1=C|last2=Bienaymé|first2=O|last3=Mishenina|first3=T. V|last4=Kovtyukh|first4=V. V|year=2008|issue=1|doi=10.1051/0004-6361:20078788|arxiv=0712.1370|s2cid=16602121}}

{{citation | title=UBV observations of miscellaneous stars | last1=Fernie | first1=J. D. | journal=Journal of the Royal Astronomical Society of Canada | volume=63 | pages=133–135 | date=June 1969 | bibcode=1969JRASC..63..133F | postscript=. }}

{{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=. }}

{{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 | bibcode=2008MNRAS.389..869E | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | arxiv = 0806.2878 | s2cid=14878976 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/MNRAS/389/869/table1&mHR=7478 Vizier catalog entry]

{{cite journal|bibcode=1992AJ....104.2217A|title=The orbit of Phi Cygni measured with long-baseline optical interferometry - Component masses and absolute magnitudes|journal=Astronomical Journal|volume=104|pages=2217|last1=Armstrong|first1=J. T|last2=Hummel|first2=C. A|last3=Quirrenbach|first3=A|last4=Buscher|first4=D. F|last5=Mozurkewich|first5=D|last6=Vivekanand|first6=M|last7=Simon|first7=R. S|last8=Denison|first8=C. S|last9=Johnston|first9=K. J|last10=Pan|first10=X.-P|last11=Shao|first11=M|last12=Colavita|first12=M. M|year=1992|doi=10.1086/116396}}

{{cite journal|bibcode=1992AJ....104.2217A|arxiv=1304.2530|title=The orbit of Phi Cygni measured with long-baseline optical interferometry - Component masses and absolute magnitudes|journal=Astronomical Journal|volume=104|pages=2217|last1=Armstrong|first1=J. T|last2=Hummel|first2=C. A|last3=Quirrenbach|first3=A|last4=Buscher|first4=D. F|last5=Mozurkewich|first5=D|last6=Vivekanand|first6=M|last7=Simon|first7=R. S|last8=Denison|first8=C. S|last9=Johnston|first9=K. J|last10=Pan|first10=X.-P|last11=Shao|first11=M|last12=Colavita|first12=M. M|year=1992|doi=10.1086/116396}}

{{Citation |last1=Piccotti |first1=Luca |last2=Docobo |first2=José Ángel |last3=Carini |first3=Roberta |last4=Tamazian |first4=Vakhtang S. |last5=Brocato |first5=Enzo |last6=Andrade |first6=Manuel |last7=Campo |first7=Pedro P. |date=2020-02-01 |title=A study of the physical properties of SB2s with both the visual and spectroscopic orbits |journal=Monthly Notices of the Royal Astronomical Society |volume=492 |issue=2 |pages=2709–2721 |doi=10.1093/mnras/stz3616 |doi-access=free |bibcode=2020MNRAS.492.2709P |issn=0035-8711}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/MNRAS/492/2709&HD=185734 Phi Cygni's database entry] at VizieR.

}}

Category:G-type giants

Category:Horizontal-branch stars

Category:Spectroscopic binaries

Category:Cygnus (constellation)

Cygni, Phi

Category:Durchmusterung objects