HD 74180

{{Starbox begin

| name=b Velorum

}}

{{Starbox image

| image=

{{Location mark

|image=Vela constellation map.svg

|float=center

|alt=

|label=

|position=right

|width=280

|mark=Red circle.svg

|mark_width=12

|mark_link=b Velorum

|x=760|y=431

}}

|caption=Location of b Vel (circled)

}}

{{Starbox observe

| epoch=J2000

| ra={{RA|08|40|37.57017}}

| dec={{DEC|−46|38|55.4770}}

| appmag_v=3.81{{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|last1=Ducati|first1=J. R.|year=2002}}

| constell=Vela

}}

{{Starbox character

| type=Yellow supergiant or yellow hypergiant

| class=F8 Ib, F0Ia⁺ or F0Ia

| r-i =

| v-r =

| b-v = +0.67

| u-b = +0.34

| variable=suspected α Cyg

}}

{{Starbox astrometry

| radial_v=−25.3{{cite journal|bibcode=1953GCRV..C......0W|title=General catalogue of stellar radial velocities|journal=Washington|last1=Wilson|first1=Ralph Elmer|year=1953}}

| prop_mo_ra=−6.124{{Cite Gaia DR3|5521599549054493696}}

| prop_mo_dec=4.473

| parallax=0.431

| p_error=0.101

| parallax_footnote=

| dist_ly=3,230{{snd}}8,250{{efn|Margin of error of {{+-|1960|1290}} for the second value}}

| dist_pc=990{{efn|This distance applies is b Velorum has spectral type F8Ib.}}{{snd}}2,532{{efn|Margin of error of {{+-|600|397}} for the second value}}

| dist_footnote=

| absmag_v=−6.50

}}

{{Starbox detail

| mass=12.63–{{val|21.4|2.3}}

| radius={{Solar radius calculator|type=LT|34040|5750}}{{efn | Applying the Stefan–Boltzmann law with a nominal solar effective temperature of {{val|5772|ul=K|fmt=commas}}:

: $\sqrt{(5772/5750)^4 * 34,040} = 185.91\ R\odot$ }}

| luminosity=34,040{{efn|name=Lbol}}

| temperature=5,750{{snd}}7,839

| metal_fe=0.56

| gravity=1.38

| rotational_velocity={{val|21.7|6}}

| age_myr={{val|7.4|0.8}}{{efn|Assuming {{solar mass|21.4}} as the mass}}

}}

{{Starbox catalog

| names=b Velorum, HR 3445, HD 74180, CD−46°4438, FK5 1226, HIP 42570, SAO 220265

}}

{{Starbox reference

| Simbad=HD+74180

}}

HD 74180 is a single star in the constellation Vela. It is a yellow-white F-type supergiant with a mean apparent magnitude of +3.81 and a spectral classification F8Ib. Estimates of its distance to Earth vary between 3,200 and 8,300 light-years.

File:HD74180LightCurve.png for HD 74180, adapted from van Leeuwen et al. (1998)]]

b Velorum has been classified as a suspected α Cygni variable star which varies by only 0.06 magnitude. There are possible periods near 53, 80, and 160 days, but the variation is largely irregular. It lies less than a degree from the small open cluster NGC 2645, but is not a member.

Several studies have considered b Velorum to be a highly luminous supergiant or hypergiant with an early F spectral type, for example F2 Ia⁺, F0 Ia,{{cite journal|bibcode=1978ApJS...38..309H|title=Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way|journal=Astrophysical Journal|volume=38|pages=309|last1=Humphreys|first1=R. M.|year=1978|doi=10.1086/190559}} and F4 I.{{cite journal|bibcode=1980A&A....85...93M|title=Prediction of spectral classification from photometric observations - Application of the UVBY beta photometry and the MK spectra classification. II - General case|journal=Astronomy and Astrophysics|volume=85|pages=93|last1=Mersch|first1=G.|last2=Heck|first2=A.|year=1980}} There were corresponding luminosity estimates of {{solar luminosity|several hundred thousand|link=y}}. A 2015 study used the Barbier-Chalonge-Divan (BCD) system to derive a luminosity of {{solar luminosity|34,000}} and a cooler less luminous F8 Ib spectral type.

Distance and size

Multiple papers give different distances for b Velorum. Bailer-Jones et al. (2021) give a distance of about {{Convert|2530|pc|ly|abbr=on|lk=on}}. The Hipparcos spacecraft give a parallax of {{Val|0.67|0.16|ul=mas}}, translating into a distance of {{Convert|1492.5|pc|ly|abbr=on}}. Aidelman et al. (2015) give a distance of {{Convert|990|pc|ly|abbr=on}}. At the Hipparcos distance, b{{nbsp}}Velorum has its apparent brightness diminished by 1.11{{nbsp}}magnitudes due to interstellar extinction.

b Velorum has an angular diameter estimated at {{Val|1.824|ul=mas}}.{{Cite journal |last1=Cruzalèbes |first1=P. |last2=Petrov |first2=R. G. |last3=Robbe-Dubois |first3=S. |last4=Varga |first4=J. |last5=Burtscher |first5=L. |last6=Allouche |first6=F. |last7=Berio |first7=P. |last8=Hofmann |first8=K. -H. |last9=Hron |first9=J. |last10=Jaffe |first10=W. |last11=Lagarde |first11=S. |last12=Lopez |first12=B. |last13=Matter |first13=A. |last14=Meilland |first14=A. |last15=Meisenheimer |first15=K. |date=2019-12-01 |title=A catalogue of stellar diameters and fluxes for mid-infrared interferometry |journal=Monthly Notices of the Royal Astronomical Society |volume=490 |issue=3 |pages=3158–3176 |doi=10.1093/mnras/stz2803 |doi-access=free |issn=0035-8711|arxiv=1910.00542 |bibcode=2019MNRAS.490.3158C }} The physical size depends on the star's distance, and could be {{sigfig|{{solar radius calculator|type=AD|1.824|0.99}}|2}}{{nbsp}}{{solar radius}} assuming the distance of Aidelman et al., {{sigfig|{{solar radius calculator|type=AD|1.824|1.4925}}|2}}{{nbsp}}{{solar radius}} assuming the Hipparcos distance, or even {{sigfig|{{solar radius calculator|type=AD|1.824|2.53}}|2}}{{nbsp}}{{solar radius}} assuming the Bailer-Jones et al. distance.

In chinese astronomy

In Chinese, {{lang|zh|天社}} ({{lang|zh-Latn|Tiān Shè}}), meaning Celestial Earth God's Temple, refers to an asterism consisting of Kappa Velorum, Gamma² Velorum, b Velorum and Delta Velorum.{{in lang|zh}} 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN|978-986-7332-25-7}}. Consequently, Kappa Velorum itself is known as {{lang|zh|天社五}} ({{lang|zh-Latn|Tiān Shè wǔ}}), "the Fifth Star of Celestial Earth God's Temple".{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm 香港太空館 – 研究資源 – 亮星中英對照表] {{webarchive|url=https://web.archive.org/web/20081025110153/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm |date=2008-10-25 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.

Notes

{{Notelist|notes=

{{efn|1=From L = 10^{(0.4*(4.74−(M_bol))}, where L is the luminosity and M_bol the bolometric magnitude|name=Lbol}}

}}

References

{{reflist|refs=

{{cite journal|bibcode= 2014AJ....147..137L|title= Parameters and Abundances in Luminous Stars|journal= The Astronomical Journal|volume= 147|issue= 6|pages= 137|last1= Luck|first1= R. Earle|year= 2014|doi= 10.1088/0004-6256/147/6/137|doi-access= free}} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/AJ/147/137&Name=*%20b%20Vel b Velorum's database entry] at VizieR.

{{citation | first1=Kenneth R. | last1=Lang | title=Astrophysical formulae | volume=1 | series=Astronomy and astrophysics library | edition=3rd | publisher=Birkhäuser | date=2006 | isbn=3-540-29692-1 | url=https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41 }}. The radius (R_*) is given by:

: $\begin{align} 2\cdot R_*
& = \frac{(10^{-3}\cdot 990\cdot 1.824)\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\
& \approx 388\cdot R_{\bigodot}
\end{align}$
$\begin{align} 2\cdot R_*
& = \frac{(10^{-3}\cdot 1493\cdot 1.824)\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\
& \approx 586\cdot R_{\bigodot}
\end{align}$
$\begin{align} 2\cdot R_*
& = \frac{(10^{-3}\cdot 2530\cdot 1.824)\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\
& \approx 993\cdot R_{\bigodot}
\end{align}$

{{citation

| last1=Ammler-von Eiff | first1=Matthias | last2=Reiners | first2=Ansgar

| title=New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?

| journal=Astronomy & Astrophysics | arxiv=1204.2459

| volume=542 | page=A116 | date=June 2012

| doi=10.1051/0004-6361/201118724 | bibcode=2012A&A...542A.116A | s2cid=53666672 }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A%2BA/542/A116&Name=HD%2074180 b Velorum's database entry] at VizieR.

{{cite journal|bibcode=2015A&A...577A..45A|title=Open clusters. II. Fundamental parameters of B stars in Collinder 223, Hogg 16, NGC 2645, NGC 3114, and NGC 6025|journal=Astronomy & Astrophysics|volume=577|pages=A45|last1=Aidelman|first1=Y.|last2=Cidale|first2=L. S.|last3=Zorec|first3=J.|last4=Panei|first4=J. A.|year=2015|doi=10.1051/0004-6361/201425085|doi-access=free|hdl=11336/14076|hdl-access=free}}

{{cite journal|doi=10.1051/aas:1998129 |title=Hipparcos photometry of 24 variable massive stars (α Cygni variables) |journal=Astronomy and Astrophysics Supplement Series |volume=128 |pages=117–129 |year=1998 |last1=Van Leeuwen |first1=F. |last2=Van Genderen |first2=A. M. |last3=Zegelaar |first3=I. |bibcode=1998A&AS..128..117V |doi-access=free }}

{{Cite journal |last1=Tetzlaff |first1=N. |last2=Neuhäuser |first2=R. |last3=Hohle |first3=M. M. |date=2011-01-01 |title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun |journal=Monthly Notices of the Royal Astronomical Society |volume=410 |issue=1 |pages=190–200 |doi=10.1111/j.1365-2966.2010.17434.x |doi-access=free |issn=0035-8711|arxiv=1007.4883 |bibcode=2011MNRAS.410..190T }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/MNRAS/410/190&HIP=42570 b Velorum's database entry] at VizieR.

{{Cite journal |last=van Leeuwen |first=F. |date=2007-11-01 |title=Validation of the new Hipparcos reduction |url=https://ui.adsabs.harvard.edu/abs/2007A&A...474..653V |journal=Astronomy and Astrophysics |volume=474 |issue=2 |pages=653–664 |doi=10.1051/0004-6361:20078357 |issn=0004-6361|arxiv=0708.1752 |bibcode=2007A&A...474..653V }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=I/311&HIP=42570 b Velorum's database entry] at VizieR.

{{Cite journal |last1=Eggleton |first1=P. P. |last2=Tokovinin |first2=A. A. |date=2008-09-01 |title=A catalogue of multiplicity among bright stellar systems |journal=Monthly Notices of the Royal Astronomical Society |volume=389 |issue=2 |pages=869–879 |doi=10.1111/j.1365-2966.2008.13596.x |doi-access=free |issn=0035-8711|arxiv=0806.2878 |bibcode=2008MNRAS.389..869E }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/MNRAS/389/869&mHR=3445 b Velorum's database entry] at VizieR.

{{Cite journal |last1=Bailer-Jones |first1=C. A. L. |last2=Rybizki |first2=J. |last3=Fouesneau |first3=M. |last4=Demleitner |first4=M. |last5=Andrae |first5=R. |date=2021-03-01 |title=Estimating distances from parallaxes. V: Geometric and photogeometric distances to 1.47 billion stars in Gaia Early Data Release 3 |journal=The Astronomical Journal |volume=161 |issue=3 |pages=147 |doi=10.3847/1538-3881/abd806 |doi-access=free |arxiv=2012.05220 |bibcode=2021AJ....161..147B |issn=0004-6256}} Data about this star can be seen [https://dc.zah.uni-heidelberg.de/gedr3dist/q/cone/form here].

}}

Velorum, b

074180

Category:Vela (constellation)

Category:Binary stars

Category:Alpha Cygni variables

Category:F-type supergiants

Category:Durchmusterung objects

042570

3445