HD 93129

{{Short description|Triple star system in the constellation Carina}}

{{Starbox begin

| name=HD 93129

}}

{{Starbox image

| image=280px

| caption=HD 93129 surrounded by the lesser stars of Trumpler 14

| credit=NASA & ESA, Jesús Maíz Apellániz (Instituto de Astrofisica de Andalucia)

}}

{{Starbox observe

| epoch=J2000

| constell=Carina

| ra={{RA|10|43|57.5}}{{cite journal|bibcode=2000A&A...355L..27H|title=The Tycho-2 catalogue of the 2.5 million brightest stars|journal=Astronomy and Astrophysics|volume=355|pages=L27|last1=Høg|first1=E.|last2=Fabricius|first2=C.|last3=Makarov|first3=V. V.|last4=Urban|first4=S.|last5=Corbin|first5=T.|last6=Wycoff|first6=G.|last7=Bastian|first7=U.|last8=Schwekendiek|first8=P.|last9=Wicenec|first9=A.|year=2000|doi=10.1888/0333750888/2862|isbn=0333750888}}

| dec={{DEC|−59|32|51.3}}

| appmag_v=6.90{{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}} {{nowrap|(7.310 + 8.84)}}

}}

{{Starbox character

| component1 = A

| class=O2If^*{{cite journal|bibcode=2014ApJS..211...10S|title=The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars|journal=The Astrophysical Journal Supplement|volume=211|pages=10|last1=Sota|first1=A.|last2=Maíz Apellániz|first2=J.|last3=Morrell|first3=N. I.|last4=Barbá|first4=R. H.|last5=Walborn|first5=N. R.|author5-link=Nolan R. Walborn|last6=Gamen|first6=R. C.|last7=Arias|first7=J. I.|last8=Alfaro|first8=E. J.|year=2014|issue=1|doi=10.1088/0067-0049/211/1/10|arxiv = 1312.6222 |s2cid=118847528}} (O2If+O3.5V{{Cite journal | last1 = Cohen | first1 = D. H. | last2 = Gagné | first2 = M. | last3 = Leutenegger | first3 = M. A. | last4 = MacArthur | first4 = J. P. | last5 = Wollman | first5 = E. E. | last6 = Sundqvist | first6 = J. O. | last7 = Fullerton | first7 = A. W. | last8 = Owocki | first8 = S. P. | doi = 10.1111/j.1365-2966.2011.18952.x | title = Chandra X-ray spectroscopy of the very early O supergiant HD 93129A: Constraints on wind shocks and the mass-loss rate | journal = Monthly Notices of the Royal Astronomical Society | volume = 415 | issue = 4 | pages = 3354–3364 | year = 2011 | doi-access = free |arxiv = 1104.4786 |bibcode = 2011MNRAS.415.3354C | s2cid = 8258609 }})

| b-v=+0.25

| u-b=−0.81

| variable=

| component2 = B

| type2 = main sequence

| class2= O3.5 V((f))z{{cite journal|bibcode=2016ApJS..224....4M|arxiv=1602.01336|title=The Galactic O-Star Spectroscopic Survey (GOSSS). III. 142 Additional O-type Systems|journal=The Astrophysical Journal Supplement Series|volume=224|pages=4|last1=Maíz Apellániz|first1=J.|last2=Sota|first2=A.|last3=Arias|first3=J. I.|last4=Barbá|first4=R. H.|last5=Walborn|first5=N. R.|last6=Simón-Díaz|first6=S.|last7=Negueruela|first7=I.|last8=Marco|first8=A.|last9=Leão|first9=J. R. S.|last10=Herrero|first10=A.|last11=Gamen|first11=R. C.|last12=Alfaro|first12=E. J.|year=2016|issue=1|doi=10.3847/0067-0049/224/1/4|s2cid=55658165 |doi-access=free }}

| b-v2=+0.23{{cite journal|bibcode= 1996A&AS..116...75V|title= Investigation on the region of the open cluster TR 14|journal= Astronomy and Astrophysics Supplement|volume= 116|pages= 75|last1= Vazquez|first1= R. A.|last2= Baume|first2= G.|last3= Feinstein|first3= A.|last4= Prado|first4= P.|year= 1996}}

| u-b2=−0.79

| variable2=

}}

{{Starbox astrometry

| radial_v=−0.4 ± 7.4

| prop_mo_ra=-5.0

| prop_mo_dec=17.0

| dist_pc=2,300

| absmag_v={{nowrap|(A): −6.5 (−6.1 + −5.2)}}
(B): −4.9{{cite journal|bibcode=2004AJ....128..323N|title=Resolving OB Systems in the Carina Nebula with the Hubble Space Telescope Fine Guidance Sensor|journal=The Astronomical Journal|volume=128|pages=323–329|last1=Nelan|first1=Edmund P.|last2=Walborn|first2=Nolan R.|last3=Wallace|first3=Debra J.|last4=Moffat|first4=Anthony F. J.|last5=Makidon|first5=Russell B.|last6=Gies|first6=Douglas R.|last7=Panagia|first7=Nino|year=2004|issue=1|doi=10.1086/420716|s2cid=121115585 |doi-access=free}}

}}

{{Starbox detail

| component1=Aa

| metal=

| mass=110

| radius=22.5

| rotational_velocity=130

| luminosity=1,480,000

| temperature=42,500

| gravity=3.71{{cite journal|bibcode=2004A&A...415..349R|title=Stellar and wind parameters of Galactic O-stars. The influence of line-blocking/blanketing|journal=Astronomy and Astrophysics|volume=415|pages=349–376|last1=Repolust|first1=T.|last2=Puls|first2=J.|last3=Herrero|first3=A.|year=2004|doi=10.1051/0004-6361:20034594|doi-access=free}}

| age_myr= {{val|0.9|0.2|0.4}}{{cite journal|bibcode=1993PASP..105..588P|title=The frequency of binary stars in the young cluster Trumpler 14|journal=Publications of the Astronomical Society of the Pacific|volume=105|pages=588|last1=Penny|first1=Laura R.|last2=Gies|first2=Douglas R.|last3=Hartkopf|first3=William I.|last4=Mason|first4=Brian D.|last5=Turner|first5=Nils H.|year=1993|doi=10.1086/133200|doi-access=free}}

| component2=Ab

| metal2=

| mass2=70

| radius2=13.1

| rotational_velocity2=

| luminosity2=575,000

| temperature2=44,000{{cite journal|bibcode=2016A&A...591A.139D|arxiv=1604.07294|title=A model for the non-thermal emission of the very massive colliding-wind binary HD 93129A|journal=Astronomy & Astrophysics|volume=591|pages=A139|last1=Del Palacio|first1=Santiago|last2=Bosch-Ramon|first2=Valentí|last3=Romero|first3=Gustavo E.|last4=Benaglia|first4=Paula|year=2016|doi=10.1051/0004-6361/201628264|s2cid=55216290}}

| gravity2=

}}

{{Starbox detail|no_heading=y

| component1 = B

| mass = 52{{cite journal|bibcode=2009A&A...505..743V|arxiv=0909.0888|title=On the presence and absence of disks around O-type stars|journal=Astronomy and Astrophysics|volume=505|issue=2|pages=743|last1=Vink|first1=Jorick S|last2=Davies|first2=B|last3=Harries|first3=T. J|last4=Oudmaijer|first4=R. D|last5=Walborn|first5=N. R|year=2009|doi=10.1051/0004-6361/200912610|s2cid=16636438}}

| radius = 13

| gravity = 3.92

| rotational_velocity = 112

| temperature = 44,000

| luminosity = 575,000{{cite journal|bibcode=2006MNRAS.367..763S|arxiv=astro-ph/0601060|title=A census of the Carina Nebula - I. Cumulative energy input from massive stars|journal=Monthly Notices of the Royal Astronomical Society|volume=367|issue=2|pages=763–772|last1=Smith|first1=Nathan|year=2006|doi=10.1111/j.1365-2966.2006.10007.x|doi-access=free |s2cid=14060690}}

}}

{{Starbox catalogue

| names = CD−58° 3528, {{nowrap|Trumpler 14 1}}, CCDM J10440-5933, WDS J10440-5933

| component1 = A

| names1 = TYC 8626-2805-1, ALS 15862, LS 1820

| component2 = B

| names2 = ALS 19309

}}

{{Starbox reference

| Simbad=HD+93129 |sn=HD 93129

| Simbad2=HD+93129A |sn2=HD 93129 A

| Simbad3=HD+93129B |sn3=HD 93129 B

}}

HD 93129 is a triple star system in the Carina Nebula, with all three components being hot O class stars amongst the most luminous stars in the Milky Way. It is the dominant member of the Trumpler 14 star cluster, a young star cluster within the Carina OB1 stellar association that harbors other super-luminous stars, like Eta Carinae and WR 25.

Location

File:ESO - The Carina Nebula (by).jpg, with η Carinae on the left and Trumpler 14 just right of center]]

HD 93129 is found at the centre of the massive Trumpler 14 open cluster in the Carina Nebula star forming region. It is too far away for its distance to have been accurately determined using the annual parallax method, but accurate distances for η Carinae and the Homunculus Nebula, modelling of clusters, and astrophysical data about other stars assumed to be within the same region, all lead to a distance around 2,300 parsecs. HD 93129 Aa is the closest O2 supergiant to Earth.

That volume of space is home to many other massive and luminous stars. HD 93128, yet another O3.5 main sequence star, is only 24' away within Trumpler 14, and HD 93250 and HD 93205 are two more O3.5 stars in the larger Trumpler 16 cluster around η Carinae. There are also three Wolf-Rayet stars, an O4 supergiant, many other class O stars, and the unique η Carinae itself.

System

Image:ESO-Trumpler14-cluster.jpg Trumpler 14 with HD 93129 A being the brightest star in the image, and HD 93129 B close but clearly resolved]]

HD 93129 consists of two clearly resolved components, HD 93129 A and HD 93129 B, and HD 93129 A itself is made up of two much closer stars.

HD 93129 A has been resolved into two components. The spectrum is dominated by the brighter component, although the secondary is only 0.9 magnitudes fainter. HD 93129 Aa is an O2 supergiant and Ab is an O3.5 main sequence star.{{cite journal |last=Benaglia |first=P. |author2=Koribalski, B. |year=2004 |title=Radio observations of HD 93129A: The earliest O star with the highest mass loss? |journal=Astronomy & Astrophysics |volume=416 |issue= 1|pages=171–178 |doi=10.1051/0004-6361:20034138 |bibcode=2004A&A...416..171B|arxiv = astro-ph/0312003|s2cid=18416034 }} Their separation has decreased from 55 mas in 2004 to only 27 mas in 2013, but an accurate orbit is not available.{{cite journal|bibcode=2014ApJS..215...15S|title=Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection|journal=The Astrophysical Journal Supplement|volume=215|pages=15|last1=Sana|first1=H.|last2=Le Bouquin|first2=J.-B.|last3=Lacour|first3=S.|last4=Berger|first4=J.-P.|last5=Duvert|first5=G.|last6=Gauchet|first6=L.|last7=Norris|first7=B.|last8=Olofsson|first8=J.|last9=Pickel|first9=D.|last10=Zins|first10=G.|last11=Absil|first11=O.|last12=De Koter|first12=A.|last13=Kratter|first13=K.|last14=Schnurr|first14=O.|last15=Zinnecker|first15=H.|year=2014|issue=1|doi=10.1088/0067-0049/215/1/15|arxiv = 1409.6304 |s2cid=53500788}}

HD 93129 B is an O3.5 main-sequence star 3 arc-seconds away from the closer pair. It is about 1.5 magnitudes fainter than the combined HD 93129 A, and approximately the same brightness as HD 93129 Ab.

A further 5 fainter stars within 5 arc-seconds have been detected, between five and seven magnitudes fainter at infrared wavelengths.

Properties

All three stars of HD 93129 are among the most luminous in the galaxy; {{solar luminosity|1,480,000}} for the supergiant primary and {{solar luminosity|575,000}} for each of the other two stars. They are also among the hottest, with the supergiant at 42,500 K and the other two at 52,000 K. The stars have masses calculated to be between {{solar mass|70}} and {{solar mass|110}}.

HD 93129Aa has left the main sequence and its age is estimated to be around 900,000 years. The existence of the zero-age main sequence stars within Trumpler 14 suggest its age may be less than 600,000 years.