Scientists Can Pinpoint Surface Gravity On Other Stars (bbc.com)

An anonymous reader writes: Astronomers have developed a new technique to measure the surface gravity on distant stars. Earlier techniques relied on measuring the amount of light coming from the star, and were unreliable beyond a certain distance. The new work instead focuses on variations in the light over a longer period of time — indications of turbulence and vibration — which can provide detailed information at greater distances. One of the researchers, Professor Jaymie Matthews, said, "Our technique can tell you how big and bright is the star, and if a planet around it is the right size and temperature to have water oceans, and maybe life." According to their research paper, "We have tested this for a well-defined subsample of the Kepler catalog and found it to maintain a high accuracy, about six times better than that of the flicker method. In addition, it is more noise-tolerant than asteroseismology and gives a reasonably accurate surface gravity g for stars that are too faint for a reliable asteroseismic analysis. Therefore, the time scale technique makes it possible to study otherwise poorly understood stars, which will lead to better characterization of exoplanetary systems both individually and statistically."

Comments

Re: Yeah, sure

[Anonymous Coward]

The density of the sun changes eleven orders of magnitude in the 2000 km above the photosphere. In a proportionate 20 km of Earth, from just below the surface to 20 km above, there is only a five orders of magnitude change in density. The chromasphere is a rather drastic boundary that works quite well as reference point to call the effect I've surface.

Link to the full research paper

[StupendousMan]

... is here:

http://advances.sciencemag.org...

The authors have not placed a copy on the arXiv preprint server ... strange.