Jean Elias Benjamin Valz (May 27, 1787 – April 22, 1867) was a French astronomer. May 27 is the 147th day (148th in leap years) of the year in the Gregorian calendar, with 218 days remaining. ... 1787 was a common year starting on Monday (see link for calendar). ... April 22 is the 112th day of the year in the Gregorian calendar (113th in leap years). ... 1867 was a common year starting on Tuesday (see link for calendar). ... An astronomer or spmething i cant inderstand is a scientist whose area of research is astronomy or astrophysics. ...

He was born in Nîmes and trained as an engineer. He became interested in astronomy and comets in particular, observing the return of what would later be named Comet Encke. He later made a very complete calculation of the orbital elements of another comet, for which he won recognition. Location within France Nîmes is a city and commune of southern France, préfecture (capital) of the Gard département. ... In ancient Greece and other early civilizations, astronomy consisted largely of astrometry, measuring positions of stars and planets in the sky. ... Photo of the comet Hale-Bopp above a tree. ... Comet Encke (officially designated 2P/Encke) is a periodic comet, named after Johann Franz Encke, who through laborious study of its orbit and many calculations was able to link multiple observations in 1786 (2P/1786 B1), 1795 (2P/1795 V1), 1805 (2P/1805 U1) and 1818 (2P/1818 W1) to... The elements of an orbit are the parameters needed to specify that orbit uniquely, given a model of two ideal masses obeying the Newtonian laws of motion and the inverse-square law of gravitational attraction. ...

In 1835 he hypothesized that irregularities in Comet Halley's orbit could be explained by an unknown planet beyond Uranus—at the time, Neptune was not yet discovered. 1835 was a common year starting on Thursday (see link for calendar). ... Comet Halley as taken with the Halley Multicolor Camera on the ESA Giotto mission. ... Atmospheric characteristics Atmospheric pressure 120 kPa Hydrogen 83% Helium 15% Methane 1. ... Atmospheric characteristics Surface pressure ≫100 MPa Hydrogen - H2 80% ±3. ...

He build a private observatory at his home and when he went to take up a post as director of the Marseille Observatory, he left his home to a young man named "A. Laurent", who used the observatory to discover the asteroid 51 Nemausa. The house, at 32 rue Nationale in Nîmes, has a plaque commemorating the discovery. [1] A. Laurent was a Frenchman who discovered the asteroid 51 Nemausa in 1858. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... 51 Nemausa is a large Main belt asteroid similar to 1 Ceres in composition. ...

Valz himself was at one time said to be the discoverer of two asteroids, 20 Massalia and 25 Phocaea, but nowadays these are credited to the Italian astronomer Annibale de Gasparis and to Valz's colleague Jean Chacornac, respectively. 20 Massalia is a large and fairly bright Main belt asteroid. ... 25 Phocaea (fo-see-a) is a Main belt asteroid. ... Annibale de Gasparis (April 9, 1819 – March 21, 1892) was an Italian astronomer. ... Jean Chacornac (June 21, 1823 – September 23, 1873) was a French astronomer. ...

External link

• http://www-obs.cnrs-mrs.fr/tricent/astronomes/valz.htm (in French)