Daniel Chalonge was a French

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 and astrophysicist. Born in Grenoble

Grenoble

Grenoble is a city in southeastern France, at the foot of the French Alps where the river Drac joins the Isère. Located in the Rhône-Alpes region, Grenoble is the capital of the department of Isère...

, Chalonge worked as an astronomer at the Observatoire de Paris, the Observatoire d'Haute Provence and the Swiss Jungfraujoch Scientific Station. One of the founders of the Institut d'astrophysique de Paris

Institut d'astrophysique de Paris

The Institut d'Astrophysique de Paris is a research institute of the CNRS, located at 98bis, Boulevard Arago in Paris, France.Among its research priorities, there are strong groups involved in extragalactic astronomy and physical cosmology....

, his studies included the stellar spectrum

Spectrum

A spectrum is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word saw its first scientific use within the field of optics to describe the rainbow of colors in visible light when separated using a prism; it has since been applied by...

 of hydrogen

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

, stellar photometry

Photometry (astronomy)

Photometry is a technique of astronomy concerned with measuring the flux, or intensity of an astronomical object's electromagnetic radiation...

 and classification, and measurement of the ozone layer

Ozone layer

The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...

. Chalonge developed a microphotometer, which was subsequently named after him. Between 1936 and 1982 he authored (or co-authored) over 90 scientific papers.

Chalonge died in Paris

Paris

Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...

.

Awards and honors

• The crater Chalonge
  Chalonge (crater)
  Chalonge is a lunar crater that is located on the far side of the Moon. It lies to the southwest of the larger crater Lewis, in the outer skirt of ejecta that surrounds the Mare Orientale impact basin...
  
   on the Moon
  Moon
  The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
  
   is named after him.
• Chalonge mountain in the Alps
  Alps
  The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
  
   is named after him.
• The International School of Astrophysics Daniel Chalonge is named after him.
• The Daniel Chalonge Museum in Erice
  Erice
  Erice is a historic town and comune in the province of Trapani in Sicily, Italy.Erice is located on top of Mount Erice, at around 750m above sea level, overlooking the city of Trapani, the low western coast towards Marsala, the dramatic Punta del Saraceno and Capo san Vito to the north-east, and...
  
  , Italy
  Italy
  Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
  
  is named after him.

External links

• International School of Astrophysics Daniel Chalonge