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]
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 mas/yr[1] Dec.: +7.41 mas/yr[1] |
| Parallax (π) | 2.51 ± 0.15 mas[1] |
| 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 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 |
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
edit- ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600. Vizier catalog en try
- ^ a b c d Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID 119257644. Vizier catalog entry
- ^ a b c d 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. Bibcode:1983PASP...95..319E. doi:10.1086/131165. S2CID 122266645.
- ^ a b Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 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. arXiv:1902.09470. Bibcode:2019MNRAS.485.3457B. doi:10.1093/mnras/stz586.
- ^ 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
- ^ a b Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 255195566.
- ^ a b c 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. arXiv:1901.07576. Bibcode:2019ApJ...872L...9P. doi:10.3847/2041-8213/ab01e1. S2CID 118963697. L9.
- ^ a b 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.
- ^ a b c Thackeray, A. D. (1966). "The spectroscopic binary δ Pictoris". Monthly Notices of the Royal Astronomical Society. 131 (3): 435. Bibcode:1966MNRAS.131..435T. doi:10.1093/mnras/131.3.435.
- ^ a b c d e f g h i 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. Bibcode:2020MNRAS.491.5489M. doi:10.1093/mnras/stz3363.
- ^ "del Pic". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2022-01-26.
{{cite web}}: CS1 maint: postscript (link) - ^ Noriega-Crespo, Alberto; et al. (February 1997). "Bow Shocks Around Runaway Stars. III. The High Resolution Maps". Astronomical Journal. 113: 780–786. Bibcode:1997AJ....113..780N. doi:10.1086/118298.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
- ^ Cousins, A. W. J. (October 1951). "Bright variable stars in southern hemisphere (first list)". The Observatory. 71: 199–201. Bibcode:1951Obs....71..199C.