The LMC wandered into our Milky Way’s neighborhood approximately 1.5 billion years ago, and now it circles our Galaxy beautifully–and ominously. Until recently, astronomers thought that the LMC would either orbit our Galaxy for many billions of years, or, because it is zipping along at such a great speed, tear itself from our Milky Way’s gravitational ties that bind, and escape from its powerful and relentless pull.
However, more recent measurements suggest an entirely different fate, both for our Galaxy and the LMC! The new calculations indicate that the LMC possesses almost 50% more dark matter that previously thought. Dark matter is a much more abundant form of matter than the “ordinary” atomic matter that we are most familiar with, and it is believed to be composed of exotic non-atomic particles that do not dance with light or any other form of electromagnetic radiation. For this reason, the mysterious dark stuff is transparent–and it haunts the Cosmos like an invisible ghost, revealing its secretive presence only by way of its gravitational influence on objects that can be seen, such as starlit galaxies.
The team of astronomers propose that since it possesses a greater than predicted mass, the LMC is quickly losing energy and is doomed to blast into our our Milky Way–which may have fatal consequences for our Solar System.
Lead scientist Dr. Marius Cautun, a postdoctoral fellow in Durham University’s (UK) Institute for Computational Cosmology, explained in a January 4, 2019 Durham University Press Release that “There is a small chance that we might not escape unscathed from the collision between the two galaxies, which could knock us out of the Milky Way and into space.”
Currently used 8-meter-class telescopes have found eclipsing binaries throughout the entire Local Group, and these systems have proven useful for distance measurements. This is because the parameters of such systems–composed of two eclipsing stars–can be determined without mass or compositional assumptions. Also, the light echoes emanating from supernova 1987A provide useful geometric measurements, without any stellar models or assumptions.
By cross-correlating differing methods of measurement, an astronomer can determine distance; the residual errors are now less than the estimated size parameters of the LMC. The results of a study using late-type eclipsing binaries, to calculate the distance more accurately, was published in the March 2013 edition of the journal Nature. This method was used to determine that the LMC’s distance is about 163,000 light-years with an accuracy of 2.2%.
The LMC is classified as an irregular galaxy and, like others of its kind, it is richly endowed with star-birthing gas and dust. For this reason, the LMC is currently in the midst of vigorous star-forming activity. It also plays host to the Tarantula Nebula, which is the most active star-birthing regions in the entire Local Group.
The LMC houses a vast range of galactic objects and phenomena that have made it famous for being an “astronomical treasure-house, a great celestial laboratory for the study of the growth and evolution of the stars,” as described by the American astronomer Robert Burnham Jr. (1931-1993). mkvmoviesking