Measuring the mass of our galaxy has always been a complex task : We ca n’t see it in full and most of it is made of sullen matter . To weigh the Milky Way , it is necessary to understand how affair move around it , and investigator at McMaster University have now come up with a new way to do just that .
The total whitish Way system , everything within 850,000 light - years from its center , weighs between 1.3 and 1.5 trillion solar volume , with the stellar disk and dark matter being about 700 billion times the volume of the Sun . The Sun has a good deal of about 2 billion billion billion tons , or about 330,000 fourth dimension the mass of Earth .
The new estimation uses mathematical group of stars , shout out spherical bunch , as well as a variety of other satellite that surround the Milky Way . The orbits of these object reckon alone on the matter content of the galaxy , so by downplay how they move , the researchers can calculate how much mass there is .
However , the novelty of the research , which will be publish in theAstrophysical Journal , is the proficiency used to estimate the velocity of the object . To obtain the full velocity , one usually measures two part : railway line - of - sight speed ( as it appears to move towards or away from us ) and the velocity across the sky .
alas , not all spheric clusters have both value usable , so the astronomer constructed a statistical method and computing equipment simulations to assess the true velocity based on the incomplete information solidification . The best values were calculated found on the most probable dispersion of issue , both visible and dark , in the Milky Way .
The method is also versatile enough to allow for estimate within any space from the center of the galax , which make the results well-heeled to compare with other studies . The generator , graduate student Gwendolyn Eadie , is stage these findings on May 31 at theCanadian Astronomical Society ’s conferencein Winnipeg .
In the paper , which can be read as a preprint onarXiv , she highlight future go for to better the model and refine its estimate . She also suggest that this method might be used to gauge the mass of other coltsfoot , although more work is necessary .
