So all cosmological redshifts, treated in GR, are gravitational redshifts, even though that latter term is not commonly used in that situation. After all, in cosmology, essentially the only thing going on is gravity- all cosmological redshifts trace the dynamical history of the metric, and that is governed by gravity, indeed that is what gravity is in GR. I realize that all the responders in this thread are using the conventional meaning, that a gravitational redshift is the redshift due to the gravity of the source doing the emitting, or some other local mass concentration encountered along the way, but not the gravity of the universe as a whole on the largest scales, the latter being considered to be "cosmological redshift." But still, it seems to me that terminology fosters misconceptions and is unfortunate, albeit standard. The best estimate for this velocity as established from pulsar observations is V/sub k/roughly-equal150 km s/sup -1/, in which case probably only 15% if these binaries will be disrupted by the supernova explosions, and therefore, almost all runaway stars should have either neutron star or black hole companions.The term "gravitational redshift" has always bothered me. =300 km s/sup -1/ will disrupt following the explosions. These models also predict that the more massive O stars will produce correspondingly more massive compact remnants, and that most binaries experiencing supernova-induced kick velocities of magnitude V/sub k/> or approx. 15, 265, 1961), both of which support the binary-supernova scenario described by van den Heuvel and Heise for the origin of runaway stars. 86, 544 (1981) (Paper III)) and also predict a lower limit at Mroughly-equal11M/sub sun/ for the masses of runaway stars, in agreement with the observational limit found by A. All of the models consistently predict an increasing relation between the peculiar space velocities and masses for more » runaway OB stars which agrees well with the observed correlations discussed in Stone (Astron. Because of uncertainties in these rates, model results are given for several reasonable choices for these rates. 232, 520 (1979) (Paper II)), these results allow explicitly for mass loss from the binary system occurring during the core hydrogen- and helium-burning stages of the primary binary star as well as during the Roche lobe overflow. Unlike the previous conservative study by Stone (Astrophys.
![gravitational redshift gravitational redshift](https://briankoberlein.com/post/gravitational-redshift/mass.png)
This paper presents new model results describing the evolution of massive close binaries from their initial ZAMS to post-supernova stages. This calls into question the heretofore suggestive correlation between the inferred core mass and host star metallicity for Saturn-mass planets. However, unlike HAT-P-12b and WASP-21b, both HAT-P-18b and HAT-P-19b orbit stars with super-solar metallicity. HAT-P-18b and HAT-P-19b join HAT-P-12b and WASP-21b in an emerging group of low-density Saturn-mass planets, with negligible inferred core masses. Comparing these observations with theoretical models, we find that HAT-P-18b and HAT-P-19b are each consistent with a hydrogen-helium-dominated gas giant planet with negligible core mass.
![gravitational redshift gravitational redshift](https://i.ytimg.com/vi/cRJLtdh9h30/maxresdefault.jpg)
The radial velocity residuals for HAT-P-19 exhibit a linear trend in time, which indicates the presence of a third body in the system.