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(Redirected from 39 Persei)
Star in the constellation Perseus
The spectrum of this star matches a stellar classification of B5 III, which indicates it is a giant star that has evolved away from the main sequence after exhausting the hydrogen at its core. It has about seven times the Sun's mass and has an estimated age of 6.8 million years. The effective temperature of the outer envelope is 14,890 K, with the energy being emitted at this temperature giving it the blue-white hue that is a characteristic of a B-type star. It is rotating rapidly with a projected rotational velocity of 190 km s, which gives a lower bound for the actual azimuthal velocity along the star's equator.
This is most probably a binary star and may be a triple star system. It has an optical companion with an apparent magnitude of +6.17 at an angular separation of 0.330 arcseconds and a position angle of 221°, but it is uncertain whether this is an optical double star or a gravitationally bound companion. The star has also been categorized as a spectroscopic binary, indicating that it has an orbiting companion that has not been separately resolved with a telescope. Finally, this star may be a member of the Melotte 20open cluster, which would make it the second-brightest member after Mirfak.
Observation with the IRAS shows an extended, ring-like feature that may be a bow wave driven by radiation pressure from the star, rather than a bubble being generated by the stellar wind. This feature has an angular size of 15 × 25 arcminutes and a peak temperature of 38 K. It has an estimated peculiar velocity of more than 30 km s, making it a runaway star.
Name and etymology
This star, together with ψ Per, σ Per, α Per, γ Per and η Per, has been called the Segment of Perseus.
^ Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E
^ Underhill, A. B.; et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society, 189 (3): 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601
Fabricius, C.; Makarov, V. V. (April 2000), "Two-colour photometry for 9473 components of close Hipparcos double and multiple stars", Astronomy and Astrophysics, 356: 141–145, Bibcode:2000A&A...356..141F
van Buren, Dave; McCray, Richard (June 1988), "Bow shocks and bubbles are seen around hot stars by IRAS", Astrophysical Journal Letters, 329: L93 – L96, Bibcode:1988ApJ...329L..93V, doi:10.1086/185184
van Buren, Dave; Noriega-Crespo, Alberto; Dgani, Ruth (December 1995), "An IRAS/ISSA Survey of Bow Shocks Around Runaway Stars", Astronomical Journal, 110: 2914, Bibcode:1995AJ....110.2914V, doi:10.1086/117739
Location of δ Persei (circled)
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