19 Cephei

{{Short description|Star in the constellation Cepheus}}

{{Starbox begin

| name=19 Cep

}}

{{Starbox image

| image=

{{Location mark

|image=Cepheus constellation map.svg|alt=|float=center|width=260

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=19 Cep

|x=674|y=942

}}

|caption=Location of 19 Cephei (circled)

}}

{{Starbox observe

| epoch=J2000

| ra={{RA|22|05|08.78995}}

| dec={{DEC|+62|16|47.3301}}

| appmag_v=5.08

| constell=Cepheus

}}

{{Starbox character

| class=O9Ib

| b-v=+0.06

| u-b=−0.91

| variable=

}}

{{Starbox astrometry

| radial_v={{val|−12.8|0.9}}

| prop_mo_ra=−1.16

| prop_mo_dec=−2.96

| parallax=1.58

| p_error=0.19

| parallax_footnote=

| dist_pc = 1,200{{cite journal|bibcode= 2015AJ....149...26A|title= The Multiplicity of Massive Stars: A High Angular Resolution Survey with the Guidance Sensor|journal= The Astronomical Journal|volume= 149|pages= 26|last1= Aldoretta|first1= E. J.|last2= Caballero-Nieves|first2= S. M.|last3= Gies|first3= D. R.|last4= Nelan|first4= E. P.|last5= Wallace|first5= D. J.|last6= Hartkopf|first6= W. I.|last7= Henry|first7= T. J.|last8= Jao|first8= W.-C.|last9= Maíz Apellániz|first9= J.|last10= Mason|first10= B. D.|last11= Moffat|first11= A. F. J.|last12= Norris|first12= R. P.|last13= Richardson|first13= N. D.|last14= Williams|first14= S. J.|year= 2015|issue= 1|doi= 10.1088/0004-6256/149/1/26|arxiv = 1410.0021 |s2cid= 58911264}}

| absmag_v=−5.45{{cite journal|bibcode=2006A&A...454..625P|arxiv=astro-ph/0604372|title=Bright OB stars in the Galaxy. III. Constraints on the radial stratification of the clumping factor in hot star winds from a combined Hα, IR and radio analysis|journal=Astronomy and Astrophysics|volume=454|issue=2|pages=625|last1=Puls|first1=J.|last2=Markova|first2=N.|last3=Scuderi|first3=S.|last4=Stanghellini|first4=C.|last5=Taranova|first5=O. G.|last6=Burnley|first6=A. W.|last7=Howarth|first7=I. D.|year=2006|doi=10.1051/0004-6361:20065073|s2cid=18271791}}

}}

{{Starbox detail

| mass=47{{Cite journal | last1 = Krticka | first1 = J. | last2 = Kubat | first2 = J. | year = 2010 | title = Comoving frame models of hot star winds. I. Test of the Sobolev approximation in the case of pure line transitions | journal = Astronomy and Astrophysics | volume = 519 | pages = A50 | arxiv = 1005.0258 | bibcode = 2010A&A...519A..50K | doi = 10.1051/0004-6361/201014111| s2cid = 118589169 }}

| radius=17.0

| luminosity=224,000

| temperature={{val|32983|1428|fmt=commas}}

| metal_fe={{val|0.06|0.08}}

| gravity={{val|3.40|0.08}}

| rotational_velocity=48

| age=

}}

{{Starbox catalog

| names= 19 Cep, BD+61°2246, HD 209975, HIP 109017, HR 8428, SAO 19849.

}}

{{Starbox reference

|Simbad=19+Cephei

}}

{{Starbox end}}

19 Cephei is a supergiant star in the northern circumpolar constellation of Cepheus. It has a spectral class of O9 and is a member of Cep OB2, an OB association of massive stars located about {{Convert|615|pc|ly}} from the Sun.

The spectrum of 19 Cephei shows line profile variability on an hourly and daily timescale. This is thought to be due to the changes in the stellar wind.

Double star catalogues list several companions for 19 Cephei. The Washington Double Star Catalog describes four companions: 11th magnitude stars 20" and 56" away, and two 15th magnitude stars 4-5" away.{{cite journal|bibcode=2001AJ....122.3466M|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|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.|year=2001|doi=10.1086/323920|doi-access=free}} The Catalog of Components of Double and Multiple Stars gives only the two 11th magnitude stars.{{cite journal|bibcode=1994CoORB.115....1D|title=Catalogue des composantes d'etoiles doubles et multiples (CCDM) premiere edition - Catalogue of the components of double and multiple stars (CCDM) first edition|journal=Com. De l'Observ. Royal de Belgique|volume=115|pages=1|last1=Dommanget|first1=J.|last2=Nys|first2=O.|year=1994}}

A scattered cluster of faint stars has been detected associated with 19 Cephei. The brightest likely members apart from 19 Cep itself are 10th magnitude stars.{{cite journal|bibcode= 2005A&A...440..403K|title= 109 new Galactic open clusters|journal= Astronomy and Astrophysics|volume= 440|pages= 403–408|last1= Kharchenko|first1= N. V.|last2= Piskunov|first2= A. E.|last3= Röser|first3= S.|last4= Schilbach|first4= E.|last5= Scholz|first5= R.-D.|year= 2005|issue= 1|doi= 10.1051/0004-6361:20052740|arxiv = astro-ph/0505019 |s2cid= 56292154}}