![Solar eclipse 1999 4](https://upload.wikimedia.org/wikipedia/commons/c/c7/Solar_eclipse_1999_4.jpg)
Coronium, also called newtonium, was the name of a suggested
chemical element
A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...
, hypothesised in the 19th century. The name, inspired by the
solar corona
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma.
The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar e ...
, was given by Gruenwald in 1887. A new atomic thin green line in the solar corona was then considered to be emitted by a new element unlike anything else seen under laboratory conditions. It was later determined to be emitted by
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
(Fe
13+), so highly ionized that it was at that time impossible to produce in a laboratory.
Solar spectroscopy
During the total
solar eclipse of 7 August 1869, a green
emission line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...
of wavelength 530.3 nm was independently observed by
Charles Augustus Young
Charles Augustus Young (15 December 1834 – 4 January 1908) one of the foremost solar spectroscopist astronomers in the United States. He observed solar eclipses and worked on spectroscopy of the Sun. He observed a solar flare with a spec ...
(1834–1908) and
William Harkness
William Harkness (December 17, 1837 – February 28, 1903) was an astronomer. He was born at Ecclefechan, Scotland, a son of James (1803–78) and Jane (née Wield) Harkness. His father was a pastor and moved the family to the United States. H ...
(1837–1903) in the
coronal spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors i ...
. Since this line did not correspond to that of any known material, it was proposed that it was due to an unknown element, provisionally named ''coronium''.
The supposed element was discovered also in the gases given off by
Mount Vesuvius
Mount Vesuvius ( ; it, Vesuvio ; nap, 'O Vesuvio , also or ; la, Vesuvius , also , or ) is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of s ...
in 1898 by a team of Italian chemists led by .
In 1902, in an attempt at a chemical conception of the
aether, the Russian chemist and chemical educator
Dmitri Mendeleev
Dmitri Ivanovich Mendeleev (sometimes transliterated as Mendeleyev or Mendeleef) ( ; russian: links=no, Дмитрий Иванович Менделеев, tr. , ; 8 February Old_Style_and_New_Style_dates">O.S._27_January.html" ;"title="O ...
hypothesized that there existed two inert chemical elements of lesser atomic weight than hydrogen. Of these two, he thought the lighter to be an all-penetrating, all-pervasive gas, and the slightly heavier one to be coronium. Later he renamed coronium as newtonium.
It was not until the 1930s that
Walter Grotrian
Walter Robert Wilhelm Grotrian (21 April 1890 in Aachen; † 3 March 1954 in Potsdam) was a German astronomer and astrophysicist.
Grotrian studied the emission line from the solar corona in the green region of the spectrum; this emission line co ...
and
Bengt Edlén
Bengt Edlén (2 November 1906, Gusum – 10 February 1993, Lund) was a Swedish professor of physics and astronomer who specialized in spectroscopy. He was the first who identified the unknown coronal spectral lines in the Corona, which was u ...
discovered that the spectral line at 530.3 nm was due to
highly ionized iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
(Fe
13+); other unusual lines in the coronal spectrum were also caused by highly charged ions, such as
nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...
, the high ionization being due to the extreme temperature of the
solar corona
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma.
The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar e ...
.
The line at 530.3 nm had previously been misclassified as iron line number 1474.
See also
*
Helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...
*
Nebulium
Nebulium was a proposed element found in astronomical observation of a nebula by William Huggins in 1864. The strong green emission lines of the Cat's Eye Nebula, discovered using spectroscopy, led to the postulation that an as yet unknown elem ...
*
Spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...
References
Further reading
*
External links
*{{cite web , title=History of Coronium , website=Laser Stars , url=http://laserstars.org/spectra/Coronium.html , access-date=2008-08-25
Misidentified chemical elements
Iron