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For stars with a degenerate helium core, there is a limit to this growth in size and luminosity, known as the tip of the red-giant branch, where the core reaches sufficient temperature to begin fusion. All stars that reach this point have an identical helium core mass of almost 0.5 M ☉, and very similar stellar luminosity and temperature ...
In the helium cores of stars in the 0.6 to 2.0 solar mass range, which are largely supported by electron degeneracy pressure, helium fusion will ignite on a timescale of days in a helium flash. In the nondegenerate cores of more massive stars, the ignition of helium fusion occurs relatively slowly with no flash. [ 14 ]
A helium flash is a very brief thermal runaway nuclear fusion of large quantities of helium into carbon through the triple-alpha process in the core of low-mass stars (between 0.8 solar masses (M ☉) and 2.0 M ☉ [1]) during their red giant phase. The Sun is predicted to experience a flash 1.2 billion years after it leaves the main sequence.
NGC 604, a giant H II region in the Triangulum Galaxy. An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. [1] It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds of light years, and density from a few to about a million particles per cubic centimetre.
When distant stars at the TRGB are measured in the I-band (in the infrared), their luminosity is somewhat insensitive to their composition of elements heavier than helium (metallicity) or their mass; they are a standard candle with an I-band absolute magnitude of –4.0±0.1. [3] This makes the technique especially useful as a distance indicator.
The 2004 novel The Bug, by Ellen Ullman, is about a programmer's attempt to find an elusive bug in a database application. [41] The 2008 Canadian film Control Alt Delete is about a computer programmer at the end of 1999 struggling to fix bugs at his company related to the year 2000 problem.
An updated version of the game, titled Dengeki Bunko: Fighting Climax Ignition (電撃文庫 FIGHTING CLIMAX IGNITION, Dengeki Bunko Faitingu Kuraimakkusu Igunishion), was released in July 2015. [7] The update contains additional characters and more balanced gameplay.
The electron affinity is 0.080 eV, which is very close to zero. [2] The helium atom is small with the radius of the outer electron shell at 0.29 Å. [2] Helium is a very hard atom with a Pearson hardness of 12.3 eV. [3] It has the lowest polarizability of any kind of atom, however, very weak van der Waals forces exist between helium and other ...