An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Divergence or disagreement, as between facts, claims, or calculations.

From L. discrepantia, from discrepantem, pr.p. of discrepare "sound differently, differ," from → dis- "apart, off" + crepare "to rattle, crack."

Nâhamxâni, from nâ- "non, un-," → a-, + hamxâni "siniging together," from ham- "together," → com-, + xâni, from xân stem of xândan "to sing; to read; to call," Mid.Pers. xwân- "to resound; to call," Av. x^van- "to sound," Proto-Iranian *huan- "to call;" cf. Skt. svan-, sváranti "to sound, make a sound, sing;" L. sonus "sound," sonare "to sound;" O.E. swinn "music, song," PIE base *suen- "to sound" (Cheung 2007).

1) For → massive stars and → supergiants, the difference between the → spectroscopic mass and the → evolutionary mass. Early studies found that the spectroscopic mass was systematically less than the evolutionary mass by as much as a factor of 2 for supergiants. Improvements in the stellar atmosphere models (taking into account → line blanketing) have decreased or eliminated the size of the discrepancy for Galactic stars. There is still a mass discrepancy for the hottest → O stars in the → Magellanic Clouds (See, e.g. Massey et al. 2009, ApJ 692, 618).
2) For a → cluster of galaxies, the apparent difference between the mass of the cluster obtained by using the → virial theorem, and the mass inferred from the total luminosities of the member galaxies.

→ mass; → discrepancy.