Astronomy:Delta Pictoris
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Pictor |
| Right ascension | 06h 10m 17.908s[1] |
| Declination | −54° 58′ 07.11″[1] |
| Apparent magnitude (V) | 4.72[2] |
| Characteristics | |
| Evolutionary stage | Main sequence[3] |
| Spectral type | B1/2(III)n[4] (B0.5:III?np + B0.5/3:)[5] |
| U−B color index | −1.00[6] |
| B−V color index | −0.229±0.008[2] |
| Variable type | β Lyr[7] + β Cep[8] |
| Astrometry | |
| Radial velocity (Rv) | +30.6±2.8[9] km/s |
| Proper motion (μ) | RA: −4.90[1] mas/yr Dec.: +7.41[1] mas/yr |
| Parallax (π) | 2.51 ± 0.15[1] mas |
| Distance | 1,300 ± 80 ly (400 ± 20 pc) |
| Absolute magnitude (MV) | −3.27[2] |
| Orbit[10] | |
| Period (P) | 1.67254 d |
| Semi-major axis (a) | ≥ 3.83 Gm (0.0256 astronomical unit|AU) |
| Eccentricity (e) | 0.050±0.17 |
| Periastron epoch (T) | 2,438,500.79±0.09 JD |
| Argument of periastron (ω) (secondary) | 90±18° |
| Semi-amplitude (K1) (primary) | 167.0±2.8 km/s |
| Details | |
| Primary | |
| Mass | 16.3[11] M☉ |
| Radius | 7.62[11] R☉ |
| Luminosity | 20,900[11] L☉ |
| Temperature | 25,200[11] K |
| Rotational velocity (v sin i) | 170[8] km/s |
| Secondary | |
| Mass | 8.6[11] M☉ |
| Radius | 5.05[11] R☉ |
| Luminosity | 4,790[11] L☉ |
| Temperature | 21,400[11] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Delta Pictoris, Latinized from δ Pictoris, is a binary star system in the southern constellation Pictor. It is visible to the naked with a combined apparent visual magnitude of 4.72.[2] The system is located at a distance of approximately 1,300 light years from the Sun based on parallax measurements,[1] and is drifting further away with a radial velocity of ~31 km/s.[9] It is a runaway star system that is generating a bow shock as it moves through the interstellar medium.[13]
The binary nature of this system was discovered by R. E. Wilson in 1914,[10] then it was found to be variable by A. W. J. Cousins in 1951.[15] A. D. A. Thackeray published orbital elements for the pair in 1966, showing they form an eclipsing double-lined spectroscopic binary with an orbital period of 1.67 days in essentially a circular orbit.[10] The low inclination of the orbital plane results in shallow eclipses.[3] The system is classified as a likely Beta Lyrae-type eclipsing binary with a peak magnitude of 4.65, which drops to 4.90 during the primary eclipse and 4.83 in the secondary eclipse.[7] It is probably a detached binary system with no circumstellar material being found.[3]
Both components of this system are massive main sequence stars[3] with a combined stellar classification of B1/2(III)n.[4] One member of the pair displays β Cep type pulsational behavior.[8] Mass estimates give a primary with 16.3 times the mass of the Sun and a secondary with about half that.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V. Vizier catalog en try
- ↑ 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. Vizier catalog entry
- ↑ 3.0 3.1 3.2 3.3 Eaton, J. A.; Wu, C. -C. (May 1983). "ANS spectrophotometry : delta Pictoris as an upper-main-sequence Algol system.". Publications of the Astronomical Society of the Pacific 95: 319–324. doi:10.1086/131165. Bibcode: 1983PASP...95..319E.
- ↑ 4.0 4.1 Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. 1. Ann Arbor, Michigan: Department of Astronomy, University of Michigan. Bibcode: 1978mcts.book.....H.
- ↑ Balona, L. A. et al. (May 2019). "Rotational modulation in TESS B stars". Monthly Notices of the Royal Astronomical Society 485 (3): 3457–3469. doi:10.1093/mnras/stz586. Bibcode: 2019MNRAS.485.3457B.
- ↑ Mermilliod, J. C. (2006). "VizieR Online Data Catalog: Homogeneous Means in the UBV System (Mermilliod 1991)". VizieR On-line Data Catalog: II/168. Originally Published in: Institut d'Astronomie 2168. Bibcode: 2006yCat.2168....0M.Vizier catalog entry
- ↑ 7.0 7.1 Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode: 2017ARep...61...80S.
- ↑ 8.0 8.1 8.2 Pedersen, May G. et al. (February 2019). "Diverse Variability of O and B Stars Revealed from 2-minute Cadence Light Curves in Sectors 1 and 2 of the TESS Mission: Selection of an Asteroseismic Sample". The Astrophysical Journal Letters 872 (1): 11. doi:10.3847/2041-8213/ab01e1. L9. Bibcode: 2019ApJ...872L...9P.
- ↑ 9.0 9.1 Evans, D. S. (1967). "The Revision of the General Catalogue of Radial Velocities". Determination of Radial Velocities and Their Applications 30: 57. Bibcode: 1967IAUS...30...57E.
- ↑ 10.0 10.1 10.2 "The spectroscopic binary δ Pictoris". Monthly Notices of the Royal Astronomical Society 131 (3): 435. 1966. doi:10.1093/mnras/131.3.435. Bibcode: 1966MNRAS.131..435T.
- ↑ 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 Malkov, Oleg Yu (February 2020). "Semidetached double-lined eclipsing binaries: Stellar parameters and rare classes". Monthly Notices of the Royal Astronomical Society 491 (4): 5489–5497. doi:10.1093/mnras/stz3363. Bibcode: 2020MNRAS.491.5489M.
- ↑ "del Pic". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=del+Pic.
- ↑ Noriega-Crespo, Alberto et al. (February 1997). "Bow Shocks Around Runaway Stars. III. The High Resolution Maps". Astronomical Journal 113: 780–786. doi:10.1086/118298. Bibcode: 1997AJ....113..780N.
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ Cousins, A. W. J. (October 1951). "Bright variable stars in southern hemisphere (first list)". The Observatory 71: 199–201. Bibcode: 1951Obs....71..199C.
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