9 Persei

{{Short description|Blue supergiant star in the constellation Perseus}}

{{about-distinguish2|i Persei|ι (iota) Persei or l Persei}}

{{Starbox begin

| name = 9 Persei

}}

{{Starbox image

|image=

{{Location mark

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

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=9 Persei

|x=782|y=220

}}

|caption=Location of 9 Persei (circled)

}}

{{Starbox observe

| epoch = J2000

| constell = Perseus

| ra = {{RA|02|22|21.43482}}{{cite DR2|457487413730043904}}

| dec = {{DEC|55|50|44.3518}}

| appmag_v = 5.15 - 5.25

}}

{{Starbox character

| class = A2 Ia{{cite journal | bibcode=1995yCat.5050....0H | title=VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991) | journal=VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H | volume=5050 | last1=Hoffleit | first1=D. | last2=Warren | first2=W. H. | year=1995 }}

| b-v = +0.37

| u-b = −0.11

| variable = α Cyg{{cite journal | bibcode=2009yCat....102025S |title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}

}}

{{Starbox astrometry

| radial_v = −15.20{{cite journal | last=Wilson | first=R. E. | year=1953 | title=General Catalogue of Stellar Radial Velocities | journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution for Science | bibcode=1953GCRV..C......0W | isbn=9780598216885 | lccn=54001336 }}

| prop_mo_ra = +0.374

| prop_mo_dec = −1.798

| parallax = 0.7603

| p_error = 0.1139

| parallax_footnote =

| absmag_v=−4.73{{citation

| display-authors=1 | last1=Huang | first1=W.

| last2=Wallerstein | first2=G. | last3=Stone | first3=M.

| title=A catalogue of Paschen-line profiles in standard stars

| journal=Astronomy & Astrophysics

| volume=547 | pages=A62 | year=2012

| bibcode=2012A&A...547A..62H | arxiv=1210.7893

| doi=10.1051/0004-6361/201219804 | s2cid=119286159 | postscript=. }}

}}

{{Starbox detail

| mass = 10.5{{cite journal | bibcode=2011MNRAS.410..190T | doi=10.1111/j.1365-2966.2010.17434.x | arxiv=1007.4883 | title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun | journal=Monthly Notices of the Royal Astronomical Society | volume=410 | pages=190–200 | year=2011 | last1=Tetzlaff | first1=N. | last2=Neuhäuser | first2=R. | last3=Hohle | first3=M. M. | issue=1 | doi-access=free | s2cid=118629873 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/MNRAS/410/190/table1&HIP=11060 Vizier catalog entry]

| radius = {{Val|88.9|3.8|2.8}}

| temperature = 9,840{{cite journal | arxiv=0903.5134 | bibcode=2009A&A...501..297Z | doi=10.1051/0004-6361/200811147 | title=Fundamental parameters of B supergiants from the BCD system | journal=Astronomy and Astrophysics | volume=501 | pages=297–320 | year=2009 | last1=Zorec | first1=J. | last2=Cidale | first2=L. | last3=Arias | first3=M. L. | last4=Frémat | first4=Y. | last5=Muratore | first5=M. F. | last6=Torres | first6=A. F. | last7=Martayan | first7=C. | issue=1 | s2cid=14969137 }}

| luminosity = {{Val|12331|2189|fmt=commas}}

| rotational_velocity = 25

| gravity = 1.74{{cite journal | bibcode=2011A&A...525A..71W | doi=10.1051/0004-6361/201015014 | arxiv=1009.1491 | title=Coudé-feed stellar spectral library – atmospheric parameters | journal=Astronomy & Astrophysics | volume=525 | pages=A71 | year=2010 | last1=Wu | first1=Yue | last2=Singh | first2=H. P. | last3=Prugniel | first3=P. | last4=Gupta | first4=R. | last5=Koleva | first5=M. | s2cid=53480665 }}

| metal_fe = +0.26

}}

{{Starbox catalog

| names = {{odlist | B=i Persei | V=V474 Per | F=9 Per | BD=+55°598 | FK5=2159 | HD=14489 | HIP=11060 | HR=685 | SAO=23256 | CCDM=J02224+5551A | GC=2836 | WDS=J02224+5551A }}{{cite simbad | title=9 Hya | access-date=April 26, 2019 }}

}}

{{Starbox reference

| Simbad = 9+Per

}}

{{Starbox end}}

File:Double Cluster.jpg. 9 Persei is the brightest star on right side of the image. North is to the left.]]

9 Persei 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 }} variable star in the northern constellation Perseus, located around 4,300 light years away from the Sun. It has the Bayer designation i Persei; 9 Persei is the Flamsteed designation. This body is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.2. It is moving closer to the Sun with a heliocentric radial velocity of −15.2 km/s. The star is a member of the Perseus OB1 association of co-moving stars.{{cite journal

| title=On the Formation of Perseus OB1 at High Galactic Latitudes

| last1=Lee | first1=Hsu-Tai | last2=Lim | first2=Jeremy

| journal=The Astrophysical Journal

| volume=679 | issue=2 | pages=1352–1363 | date=June 2008

| doi=10.1086/587801 | arxiv=0804.4520

| bibcode=2008ApJ...679.1352L | s2cid=14252530 }}

File:V474PerLightCurve.png for V474 Persei. The main plot shows the variation over a year, and the inset plot shows the same data folded over the best-fit period. The data was published by Burggraaff et al. (2018)]]

This is a blue supergiant with a stellar classification of A2 Ia, a massive star that has used up its core hydrogen and is now fusing heavier elements. It is an Alpha Cygni variable (designated V474 Persei), a type of non-radial pulsating variable. It ranges in magnitude from 5.15 down to 5.25.{{citation

| display-authors=1 | last1=Samus | first1=N. N.

| last2=Kazarovets | first2=E. V. | last3=Durlevich | first3=O. V.

| last4=Kireeva | first4=N. N. | last5=Pastukhova | first5=E. N.

| title=General Catalogue of Variable Stars

| version=5.1 | journal=Astronomy Reports

| year=2017 | volume=61 | issue=1 | pages=80–88

| doi=10.1134/S1063772917010085 | bibcode=2017ARep...61...80S | s2cid=125853869 | postscript=. }} The star has 10.5 times the mass of the Sun and has expanded to 89 times the Sun's radius. It is radiating over 12,000 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 9,840 K.

9 Persei has one visual companion, designated component B, at an angular separation of {{val|12.3|ul=arcsecond}} and magnitude 12.0.{{cite journal | bibcode=2001AJ....122.3466M | doi=10.1086/323920 | title=The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog | journal=The Astronomical Journal | volume=122 | issue=6 | pages=3466 | year=2001 | last1=Mason | first1=Brian D. | last2=Wycoff | first2=Gary L. | last3=Hartkopf | first3=William I. | last4=Douglass | first4=Geoffrey G. | last5=Worley | first5=Charles E. | doi-access=free }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=B/wds/wds&WDS=02224%2B5551 Vizier catalog entry]

{{clear left}}