Search results
Results from the WOW.Com Content Network
The observable universe contains as many as an estimated 2 trillion galaxies [36] [37] [38] and, overall, as many as an estimated 10 24 stars [39] [40] – more stars (and, potentially, Earth-like planets) than all the grains of beach sand on planet Earth. [41] [42] [43] Other estimates are in the hundreds of billions rather than trillions.
This serves as a working definition even though there is no single agreed-upon definition of what constitutes a void. The matter density value used for describing the cosmic mean density is usually based on a ratio of the number of galaxies per unit volume rather than the total mass of the matter contained in a unit volume. [9]
The observable universe contains as many as an estimated 2 trillion galaxies [95] [96] [97] and, overall, as many as an estimated 10 24 stars [98] [99] – more stars (and earth-like planets) than all the grains of beach sand on planet Earth; [100] [101] [102] but less than the total number of atoms estimated in the universe as 10 82; [103] and ...
Galaxies, averaging an estimated 100 million stars, [3] range in size from dwarfs with less than a thousand stars, [4] to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's centre of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few per cent of that mass ...
Total mass–energy of our galaxy, the Milky Way, including dark matter and dark energy [342] [343] 1.4×10 59 J Mass-energy of the Andromeda galaxy (M31), ~0.8 trillion solar masses. [344] [345] 10 62 1–2×10 62 J: Total mass–energy of the Virgo Supercluster including dark matter, the Supercluster which contains the Milky Way [346] 10 70: ...
For stars with similar metallicity to the Sun, the theoretical minimum mass the star can have, and still undergo fusion at the core, is estimated to be about 75 M J. [ 13 ] [ 14 ] When the metallicity is very low, however, a recent study of the faintest stars found that the minimum star size seems to be about 8.3% of the solar mass, or about 87 ...
The vacuum energy, that is, the particle-antiparticle pairs generated and mutually annihilated within a time frame in accord with Heisenberg's uncertainty principle in the energy-time formulation, has been often invoked as the main contribution to dark energy. [24] The mass–energy equivalence postulated by general relativity implies that the ...
Stars less massive than 0.25 M ☉, called red dwarfs, are able to fuse nearly all of their mass while stars of about 1 M ☉ can only fuse about 10% of their mass. The combination of their slow fuel-consumption and relatively large usable fuel supply allows low mass stars to last about one trillion ( 10 × 10 12 ) years; the most extreme of 0. ...