Washington, Dec 16 (ANI): A Swiss astrophysicist has for the first time detected a low-mass star in globular cluster M22 through microlensing.
The result indicates that the overall mass of globular clusters might well be explained without enigmatic dark matter.
Until now, it was merely assumed that low-mass and therefore extremely faint stars must exist.
However, in view of the vast distances and weak luminosity of low-mass stars, even the most modern telescopes fail.
Philippe Jetzer from the University of Zurich, together with a Polish-Chilean team of researchers, has now detected the first low-mass star in the globular cluster M22 indirectly.
According to them, it involves a dwarf star that has less than a fifth of the mass of our sun and is 3.2 kiloparsecs from it (one kiloparsec corresponding to 3,210 light years).
The evidence, which enables the mass to be determined highly accurately, is based upon so-called gravitational microlensing and requires the highest technical standards available.
Gravitational microlensing is based on the fact that light spreads along a curved path near large masses as opposed to in a straight line.
"The detailed analysis revealed that the source was outside M22. A low-mass star acted as a lens within the globular cluster itself," explained Jetzer.
"The overall mass or at least a significant proportion of globular clusters can now be explained through the presence of previously undetected low-mass, faint stars," he added.
The finding will appear in Astrophysical Journal Letters. (ANI)
|
|
Comments:
