Open AccessComment on ‘The case and fate of HD 75767 – neutron star or supernova?’ by Fuhrmann et al.
Author(s) -
Griffin R. F.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10211.x
Subject(s) - physics , eccentricity (behavior) , orbit (dynamics) , astronomy , astrophysics , neutron star , white dwarf , star (game theory) , radial velocity , supernova , orbital elements , orbital eccentricity , circular orbit , stars , law , aerospace engineering , political science , engineering
In a recent paper Fuhrmann et al. presented radial‐velocity measurements of HD 75767 and derived an orbit that was an improvement on the one published by Sanford in 1931; an orbit published in 1991 was, however, overlooked, and the actual calculation of the new elements is open to criticism. A joint solution of all the available data provides a better result than any of the three constituent sets separately; the period is determined to a precision more than 100 times better than in the recent orbit, and a very small but definite eccentricity is reliably documented for the first time. The eccentricity is probably caused (or maintained) by the visual companion. Fuhrmann et al.'s conclusion that the secondary object in the spectroscopic orbit is a white dwarf does not seem inescapable; indeed, the object appears quite likely to be a lower‐main‐sequence star.