Search results
Results From The WOW.Com Content Network
Comparison of the night sky with the night sky of a hypothetical planet within the Milky Way 10 billion years ago, at an age of about 3.6 billion years and 5 billion years before the Sun formed. [261] Globular clusters are among the oldest objects in the Milky Way, which thus set a lower limit on the age of the Milky Way.
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. [7] At a distance of around 50 kiloparsecs (163,000 light-years), [2] [8] [9] [10] the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (c. 16 kiloparsecs (52,000 light-years) away) and the possible dwarf irregular galaxy called the Canis Major Overdensity.
The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane parallel to an approximation of the galactic plane but offset to its north. It uses the right-handed convention ...
Satellite galaxies that orbit from 1,000 ly (310 pc) of the edge of the disc of the Milky Way Galaxy to the edge of the dark matter halo of the Milky Way at 980,000 ly (300 kpc) from the center of the galaxy, [ a ] are generally depleted in hydrogen gas compared to those that orbit more distantly. This is because of their interactions with the ...
The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy. [1][2] Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, [3][4][5] a compact radio source which is almost exactly at the galactic rotational center ...
A 2013 study by Ravi Kumar Kopparapu put η e, the fraction of stars with planets in the HZ, at 0.48, [4] meaning that there may be roughly 95–180 billion habitable planets in the Milky Way. [120] However, this is merely a statistical prediction; only a small fraction of these possible planets have yet been discovered. [121]
Dashed black lines: Uncertain calibration ladder step. The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A direct distance measurement of an astronomical object is possible only for those objects that are "close enough ...
Coordinate systems in astronomy can specify an object's relative position in three-dimensional space or plot merely by its direction on a celestial sphere, if the object's distance is unknown or trivial. Spherical coordinates, projected on the celestial sphere, are analogous to the geographic coordinate system used on the surface of Earth.