A 6.5-day periodicity in the recurrent nova V404 Cygni implying the presence of a black hole

Casares, J.; Charles, P. A.; Naylor, T.
Bibliographical reference

Nature (ISSN 0028-0836), vol. 355, Feb. 13, 1992, p. 614-617.

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2
1992
Number of authors
3
IAC number of authors
1
Citations
244
Refereed citations
215
Description
Two years after its outburst in 1989, the William Herschel Telescope has been used to find absorption features in V404 Cyg characteristic of a late G or early K star with a radial velocity curve of amplitude 211 +/- 4 km/s and period 6.473 +/- 0.001 days. The deduced mass function of 6.26 +/- 0.31 solar masses is a firm lower limit to the mass of the compact object, which for reasonable assumptions of orbital inclination and companion star mass must be a black hole with probable mass in the range 8-15.5 solar masses.