A period of Stellar evolution undertaken by all low to intermediate mass stars (0.4-10 solar masses) late in their life. The Asymptotic Giant Branch is the name given to a region of the Hertzsprung-Russell Diagram populated by evolving low to medium-mass stars. When a star exhausts the supply of hydrogen in its core, the core contracts and its temperature increases, causing the outer layers of the star to expand and cool. The star's luminosity increases greatly, and it becomes a red giant, following a track leading into the upper-right hand corner of the HR diagram. In astronomy, stellar evolution is the sequence of changes that a star undergoes during its lifetime; the hundreds of thousands, millions or billions of years during which it emits light and heat. ... The Hertzsprung-Russell diagram (usually referred to by the abbreviation H-R diagram or HRD, also known as a Colour-Magnitude diagram, or CMD) shows the relationship between absolute magnitude, luminosity, classification, and surface temperature of stars. ... This article is about the astronomical object. ... This article is about the chemistry of hydrogen. ... Cross section of a red giant showing nucleosynthesis and elements formed According to the Hertzsprung-Russell diagram, a red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giant stars. ...

Eventually, once the temperature in the core has reached approximately 3x10⁸K, helium burning begins. The onset of helium burning in the core halts the star's cooling and increase in luminosity, and the star instead moves back towards the left hand side of the HR diagram. This is the Horizontal Branch (for population II stars) or Red Clump (for population I stars). After the completion of helium burning in the core, the star again moves to the right and upwards on the diagram. Its path is almost aligned with its previous red giant track, hence the name of Asymptotic Giant Branch. Stars at this stage of stellar evolution are known as AGB stars. Fig. ... The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... Metal-poor is a term that is used to describe the chemical make up of an object. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... According to the Hertzsprung-Russell diagram, a red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giants. Examples include Aldebaran and Arcturus. ... In mathematics and applications, particularly the analysis of algorithms, asymptotic analysis is a method of classifying limiting behaviour, by concentrating on some trend. ...

AGB stars derive their energy from fusion of hydrogen in a thin shell around the core, inside of which lies an inactive helium shell, and the very core of an AGB star consists mainly of carbon and oxygen. The outer layers of the star extent to large radii, of about one astronomical unit, and are convective. On periods of 10,000 to 100,000 years the helium shell switches on, and the hydrogen shells switches off, a process known as a helium shell flash. During these flashes material from the core region is mixed into the outer layers, changing its composition. This process can lead to the formation of Carbon stars. This article is about the chemistry of hydrogen. ... General Name, Symbol, Number helium, He, 2 Chemical series noble gases Group, Period, Block 18, 1, s Appearance colorless Atomic mass 4. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... The astronomical unit (AU or au or a. ... A carbon star is a red giant (or occasionally red dwarf) star whose atmosphere contains more carbon than oxygen; the two elements combine in the upper layers of the star, forming carbon monoxide and other carbon compounds. ...

AGB stars are typically long period variables, and suffer large mass loss in the form of a stellar wind. A star may lose 50 to 70% of its mass during the AGB phase. The stellar winds from AGB stars are sites of cosmic dust formation, and are believed to be the main producers of dust in the universe. The stellar winds of AGB stars are often the site of maer emission. A long period variable is a type of variable star in which variations in brightness occur over long timescales of months or years. ... Porous chondrite interplanetary dust particle. ... An astrophysical maser is a naturally occurring source of stimulated spectral line emission, typically in the microwave portion of the electromagnetic spectrum. ...

After these stars have lost nearly all of their envelope, and only the core region remains, they evolve further into short lived protoplanetary nebulae which are in turn followed by planetary nebulae. The Egg Nebula, a protoplanetary nebula in Cygnus A protoplanetary nebula (PPN) is an astronomical object which is formed as a star evolves into a planetary nebula. ... NGC 6543, the Cats Eye Nebula A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by certain types of stars at the end of their lives. ...

See also

• Mira
• Carbon stars
• Planetary nebulae