Search results
Results From The WOW.Com Content Network
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable (i.e. non- dark ) matter in the universe is either hydrogen or helium, and astronomers use the word "metals" as convenient shorthand for "all elements except hydrogen and helium" .
Metallicity comparison: [Fe/H] - Ratio of Iron to Hydrogen. This is not an exact ratio, but rather a logarithmic representation of the ratio of a star's iron abundance compared to that of the Sun.
Astronomy - Wikipedia
It is not just heavy metals which can be toxic; other metals (for example beryllium and lithium) can be toxic too. [267] Sleeping in a closed room with an electric fan running does not result in "fan death", as is widely believed in South Korea among older people. [268] [269] As of 2019 this belief was in decline. [270]
The metallicity distribution function is an important concept in stellar and galactic evolution.It is a curve of what proportion of stars have a particular metallicity ([Fe/H], the relative abundance of iron and hydrogen) of a population of stars such as in a cluster or galaxy.
Within a few million years the light from bright stars will have boiled away this molecular cloud of gas and dust. The cloud has broken off from the Carina Nebula.Newly formed stars are visible nearby, their images reddened by blue light being preferentially scattered by the pervasive dust.
The discipline is an overlap of astronomy and chemistry. The word "astrochemistry" may be applied to both the Solar System and the interstellar medium . The study of the abundance of elements and isotope ratios in Solar System objects, such as meteorites , is also called cosmochemistry , while the study of interstellar atoms and molecules and ...
The diagram shows the iron abundance, [Fe/H], on the x-axis and the abundance of alpha process elements, [α/Fe], on the y-axis. The data from Wallerstein (1962) is shown as red circles on top of the 2020 public data from the large scale stellar spectroscopic surveys APOGEE (DR16) and GALAH (DR3).