In 1949,Joseph Algernon Pearce derived theorbital elements for DH Cephei (then known as HD 215835) and predicted that the binary pair would show eclipses, although he had no data to prove that.[13] Graham Hillet al. confirmed the predictedvariability of star's brightness, in 1976.[14] Although initially suspected to be aneclipsing binary and given avariable star designation,[8] it doesn't appear to be eclipsing.[3] Instead, the system displaysellipsoidal light variations that are caused by tidal distortions.[7]
This system lies at the center of the youngopen clusterNGC 7380. It is the primaryionizing source for the surroundingH II region designated S142. The pair are a source ofX-ray emission, which may be the result of collidingstellar winds.[15] Their measured X-ray luminosity is3.2×1031 erg s−1.[9] The location and rare class of these stars make them an important object for astronomical studies.[8]
^abPenny, Laura R.; et al. (July 1997), "Tomographic Separation of Composite Spectra. IV. The Physical Properties of the Massive Close Binary DH Cephei",The Astrophysical Journal,483 (1):439–448,Bibcode:1997ApJ...483..439P,doi:10.1086/304239.
^abcHilditch, R. W.; et al. (October 1996), "New masses for the O-type binary DH Cephei, and the temperatures of O-stars.",Astronomy and Astrophysics,314:165–172,Bibcode:1996A&A...314..165H.
^Sinnott, Roger W.; Perryman, Michael A. C. (1997),Millennium Star Atlas, vol. 3, Sky Publishing Corporation and the European Space Agency, p. 1071,ISBN0-933346-84-0.
^abSturm, E.; Simon, K. P. (February 1994), "Spectroscopic analysis of hot binaries. I. The components of DH Cephei",Astronomy and Astrophysics,282:93–105,Bibcode:1994A&A...282...93S.
