HD 38029
  | |
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Dorado |
| A | |
| Right ascension | 05h 36m 54.63s[1] |
| Declination | −69° 11′ 38.1″[1] |
| Apparent magnitude (V) | 12.18[2] |
| B | |
| Right ascension | 05h 36m 55.19s[3] |
| Declination | −69° 11′ 37.6″[3] |
| Apparent magnitude (V) | 11.56±0.01[4] |
| Characteristics | |
| A | |
| Evolutionary stage | Wolf-Rayet[5] |
| Spectral type | WC4 + O6–6.5III[5] |
| B | |
| Evolutionary stage | Hypergiant |
| Spectral type | B1Ia+[6] |
| Astrometry | |
| Radial velocity (Rv) | 265.2[6] km/s |
| Distance | 163,000[citation needed] ly |
| B | |
| Proper motion (μ) | RA: +1.878[3] mas/yr Dec.: +0.661[3] mas/yr |
| Parallax (π) | 0.0360±0.0178 mas[3] |
| Distance | approx. 90,000 ly (approx. 30,000 pc) |
| Details | |
| B | |
| Mass | 71[7] M☉ |
| Radius | 74[8] R☉ |
| Luminosity | 1,072,000[8] L☉ |
| Surface gravity (log g) | 2.50[8] cgs |
| Temperature | 21,000[8] K |
| Rotational velocity (v sin i) | 48[7] km/s |
| Age | 2.9[8] Myr |
| Other designations | |
| HD 38029, BAT99-85, Brey 67, CPD−69°429, TIC 277172073, 2MASS J05365516-6911376, AKARI-IRC-V1 J0536538-691140, WISE J053654.95-691137.9[9] | |
| A: VFTS 2, SK −69 223[1] | |
| B: VFTS 3, SK −69 224[10] | |
| Database references | |
| SIMBAD | AB |
| A | |
| B | |
HD 38029 is a multiple star system located in the constellation of Dorado, in the Large Magellanic Cloud (LMC), one of the Milky Way's nearest satellite galaxies at a distance of approximately 163,000 light-years. The system lies near the prominent Tarantula Nebula star-forming region, a site of intense massive star formation. It consists of a carbon-sequence Wolf–Rayet (WR) primary star (HD 38029A) paired with a type O giant companion, along with a nearby luminous B supergiant (HD 38029B) that is likely part of the same small star cluster named BSDL 2586.[5][11] The combined magnitude of the three stars is 10.92.[12] HD 38029 is notable for its strong stellar winds and has been studied extensively for insights into massive star evolution, interstellar medium interactions, and diffuse interstellar bands (DIBs) in low-metallicity environments like the LMC.[13]
Charecterstics
[edit]HD 38029A is classified as a WC4 + O6–6.5 III binary, where the primary is a hot, helium and carbon-rich WR star exhibiting broad emission lines from its intense stellar winds, and the secondary is an O-type giant.[5] Earlier observations classified the WR component as WC5.[14] The WR star's spectrum shows prominent carbon lines (e.g., CIV, CIII) indicative of the carbon sequence (WC subtype), marking it as an evolved massive star (initial mass likely >25 solar masses) in a pre-supernova phase with high mass-loss rates. The system's radial velocity is approximately +265 km/s, consistent with LMC membership.[9]
The nearby HD 38029B is a B1 Ia+ hyper/supergiant with broad Balmer absorption lines potentially distorted by DIBs along the line of sight, located about 2.8 arcseconds (~0.8 parsecs at LMC distance) from HD 38029A.[5] The combined visual magnitude of the system is 11.55, with moderate reddening E(B−V) ≈ 0.32 due to LMC interstellar dust.[15] The WR winds drive an expanding interstellar bubble, contributing to feedback in the 30 Doradus region, analogous to structures in the Milky Way's Orion Nebula.[15]
Observation
[edit]HD 38029 has been observed with the Hubble Space Telescope's Cosmic Origins Spectrograph (COS) under program GO-12581, yielding far-ultraviolet spectra (G130M/1327 + G160M/1577/1589/1600) on 24 October 2012 to probe wind lines (e.g., SiIV λλ1393, 1402) and interstellar features.[16] These data support studies of massive star winds in low-metallicity settings and DIB properties in the LMC.[13] It is also part of the ULLYSES (Ultraviolet Legacy Library of Young Stars as Essential Standards) survey, providing archival UV data for evolutionary models.[15]
Ground-based spectroscopy from the VFTS has revealed broad Balmer wings in the B supergiant component, offering tests for atmospheric models distorted by foreground DIBs.[5]
References
[edit]- ^ a b c "HD 38029A". simbad.cds.unistra.fr. Retrieved 2025-12-17.
- ^ Neugent, Kathryn F.; Massey, Philip; Morrell, Nidia (2018). "A Modern Search for Wolf-Rayet Stars in the Magellanic Clouds. IV. A Final Census". The Astrophysical Journal. 863 (2): 181. arXiv:1807.01209. Bibcode:2018ApJ...863..181N. doi:10.3847/1538-4357/aad17d.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ Zacharias, N.; Finch, C. T.; Girard, T. M.; Henden, A.; Bartlett, J. L.; Monet, D. G.; Zacharias, M. I. (July 2012). "VizieR Online Data Catalog: UCAC4 Catalogue (Zacharias+, 2012)". VizieR Online Data Catalog. 1322: I/322A. Bibcode:2012yCat.1322....0Z.
- ^ a b c d e f Walborn, Nolan R.; Sana, Hugues; Evans, Christopher J.; Taylor, William D.; Sabbi, Elena; Barbá, Rodolfo H.; Morrell, Nidia I.; Apellániz, Jesús Maíz; Sota, Alfredo; Dufton, Philip L.; McEvoy, Catherine M.; Clark, J. Simon; Markova, Nevena; Ulaczyk, Krzysztof (2015-08-13). "Broad Balmer Wings in Ba Hyper/Supergiants Distorted by Diffuse Interstellar Bands: Five Examples in the 30 Doradus Region from the VLT-Flames Tarantula Survey". The Astrophysical Journal. 809 (2): 109. arXiv:1508.03021. Bibcode:2015ApJ...809..109W. doi:10.1088/0004-637X/809/2/109. ISSN 1538-4357.
- ^ a b Evans, C. J.; Kennedy, M. B.; Dufton, P. L.; Howarth, I. D.; Walborn, N. R.; Markova, N.; Clark, J. S.; De Mink, S. E.; De Koter, A.; Dunstall, P. R.; Hénault-Brunet, V.; Maíz Apellániz, J.; McEvoy, C. M.; Sana, H.; Simón-Díaz, S.; Taylor, W. D.; Vink, J. S. (2015). "The VLT-FLAMES Tarantula Survey. XVIII. Classifications and radial velocities of the B-type stars". Astronomy and Astrophysics. 574: A13. arXiv:1501.04108. Bibcode:2015A&A...574A..13E. doi:10.1051/0004-6361/201424414.
- ^ a b McEvoy, C. M.; Dufton, P. L.; Evans, C. J.; Kalari, V. M.; Markova, N.; Simón-Díaz, S.; Vink, J. S.; Walborn, N. R.; Crowther, P. A.; De Koter, A.; De Mink, S. E.; Dunstall, P. R.; Hénault-Brunet, V.; Herrero, A.; Langer, N.; Lennon, D. J.; Maíz Apellániz, J.; Najarro, F.; Puls, J.; Sana, H.; Schneider, F. R. N.; Taylor, W. D. (2015). "The VLT-FLAMES Tarantula Survey. XIX. B-type supergiants: Atmospheric parameters and nitrogen abundances to investigate the role of binarity and the width of the main sequence". Astronomy and Astrophysics. 575: A70. arXiv:1412.2705. Bibcode:2015A&A...575A..70M. doi:10.1051/0004-6361/201425202.
- ^ a b c d e Schneider, F. R. N.; et al. (2018). "An excess of massive stars in the local 30 Doradus starburst". Science. 359 (6371): 69–71. arXiv:1801.03107. Bibcode:2018Sci...359...69S. doi:10.1126/science.aan0106. PMID 29302009.
- ^ a b "HD 38029". simbad.cds.unistra.fr. Retrieved 2025-12-17.
- ^ "HD 38029B". simbad.cds.unistra.fr. Retrieved 2025-12-17.
- ^ "BSDL 2586". simbad.cds.unistra.fr. Retrieved 2026-02-09.
- ^ Lasker, Barry M.; Lattanzi, Mario G.; McLean, Brian J.; Bucciarelli, Beatrice; Drimmel, Ronald; Garcia, Jorge; Greene, Gretchen; Guglielmetti, Fabrizia; Hanley, Christopher; Hawkins, George; Laidler, Victoria G.; Loomis, Charles; Meakes, Michael; Mignani, Roberto; Morbidelli, Roberto; Morrison, Jane; Pannunzio, Renato; Rosenberg, Amy; Sarasso, Maria; Smart, Richard L.; Spagna, Alessandro; Sturch, Conrad R.; Volpicelli, Antonio; White, Richard L.; Wolfe, David; Zacchei, Andrea (2008). "The Second-Generation Guide Star Catalog: Description and Properties". The Astronomical Journal. 136 (2): 735. arXiv:0807.2522. Bibcode:2008AJ....136..735L. doi:10.1088/0004-6256/136/2/735.
- ^ a b Cox, N. L. J.; Cordiner, M. A.; Cami, J.; Foing, B. H.; Sarre, P. J.; Kaper, L.; Ehrenfreund, P. (March 2006). "The Large Magellanic Cloud: diffuse interstellar bands, atomic lines and the local environmental conditions". Astronomy & Astrophysics. 447 (3): 991–1009. doi:10.1051/0004-6361:20053367. ISSN 0004-6361.
- ^ Morel, M. (1988). "LMC Wolf-rayet stars in the HD and HDE catalogues : A brief census". Bulletin d'Information du Centre de Donnees Stellaires. 35: 31. Bibcode:1988BICDS..35...31M.
- ^ a b c "ULLYSES LMC Targets". ullyses.stsci.edu. Retrieved 2026-02-09.
- ^ Shepard, Katherine; Gies, Douglas R.; Lester, Kathryn V.; Wang, Luqian; Guo, Zhao; Kaper, Lex; De Koter, Alex; Sana, Hugues (2020-01-10). "HST/COS Spectra of the Wind Lines of VFTS 102 and 285". The Astrophysical Journal. 888 (2): 82. doi:10.3847/1538-4357/ab5a82. ISSN 0004-637X.
