Norman Robert Pogson (March 23, 1829 – June 23, 1891) was a British astronomer. An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... 42 Isis is a large main belt asteroid. ... May 23 is the 143rd day of the year in the Gregorian calendar (144th in leap years). ... 1856 was a leap year starting on Tuesday (see link for calendar). ... 43 Ariadne (AIR ee ADD nee) is a fairly large and bright main belt asteroid. ... April 15 is the 105th day of the year in the Gregorian calendar (106th in leap years). ... 1857 was a common year starting on Thursday (see link for calendar). ... 46 Hestia is a large, dark Main belt asteroid. ... August 16 is the 228th day of the year (229th in leap years) in the Gregorian Calendar. ... 1857 was a common year starting on Thursday (see link for calendar). ... 67 Asia is a bright main belt asteroid. ... April 17 is the 107th day of the year in the Gregorian calendar (108th in leap years). ... 1861 is a common year starting on Tuesday. ... 80 Sappho is a quite large main belt asteroid. ... May 2 is the 122nd day of the year in the Gregorian calendar (123rd in leap years). ... 1864 was a leap year starting on Friday (see link for calendar). ... 87 Sylvia (sil-vee-a) is one of the largest main belt asteroids. ... May 16 is the 136th day of the year in the Gregorian Calendar (137th in leap years). ... 1866 is a common year starting on Monday. ... 107 Camilla is one of the largest main belt asteroids. ... November 17 is also the name of a Marxist group in Greece. ... 1868 was a leap year starting on Wednesday (see link for calendar). ... 245 Vera is a large Main belt asteroid. ... February 6 is the 37th day of the year in the Gregorian Calendar. ... 1885 is a common year starting on Thursday. ... March 23 is the 82nd day of the year in the Gregorian Calendar (83rd in Leap years). ... 1829 was a common year starting on Thursday (see link for calendar). ... June 23 is the 174th day of the year (175th in leap years) in the Gregorian Calendar, with 191 days remaining. ... 1891 was a common year starting on Thursday (see link for calendar). ... An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ...

He was born at Nottingham, England. By the time he was 18 years old, he had computed the orbits of two comets. Nottingham is a city located in Nottinghamshire, in the East Midlands of England. ... Royal motto: Dieu et mon droit (French: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area  - Total Ranked 1st UK 130,395 km² Population  - Total (2001)  - Density Ranked 1st UK 49,138,831 377/km² Ethnicity...

He became an assistant at Radcliffe Observatory in Oxford, England in 1851. In 1860 he travelled to Madras, India, becoming the government astronomer. At the Madrid Observatory he produced the Madras Catalogue of 11,015 stars. He also discovered five asteroids and six variable stars. Oxford is a city and local government district in Oxfordshire, England, with a population of 134,248 (2001 census). ... 1852 was a common year starting on Wednesday (see link for calendar). ... 1860 is the leap year starting on Sunday. ... Chennai (சென்னை in Tamil), formerly known as Madras is the capital of the state of Tamil Nadu and is Indias fourth largest city. ... An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... Most stars are of nearly constant luminosity. ...

His most notable contribution was to note that in the stellar magnitude system introduced by the Greek astronomer Hipparchus, stars of the first magnitude were about a hundred times as bright as stars of the sixth magnitude. His suggestion in 1856 was to make this a standard, so each decrease in magnitude represented a decrease in brightness equal to the fifth-root of 100 (or about 2.512). The Pogson Ratio became the standard method of assigning magnitudes. The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... For the Athenian tyrant, see Hipparchus (son of Pisistratus). ... 1856 was a leap year starting on Tuesday (see link for calendar). ...

The magnitude relation is given as follows:

m₂ − m₁ = − 2.5log₁₀(L₂ / L₁)

where m is the stellar magnitude and L is the luminosity, for stars 1 and 2. // In General Physics In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given direction. ...

In 1868 and 1871, Pogson joined the Indian solar eclipse expeditions. 1868 was a leap year starting on Wednesday (see link for calendar). ... 1871 was a common year starting on Sunday (see link for calendar). ... Total solar eclipse in Zambia, 2001 An eclipse (Greek verb: ecleipo = cease to exist) is an astronomical event that occurs when one celestial object moves into the shadow of another. ...

During his career he discovered a total of eight asteroids and 21 variable stars. He headed the Madras Observatory for 30 years until his death. Most stars are of nearly constant luminosity. ...

Honors

The following celestial features are named after him:

• Asteroid 1830 Pogson.
• Pogson crater on the Moon.

An asteroid is a small, solid object in our Solar System, orbiting the Sun. ... Pogson is a lunar crater on the Moons far side, behind the southeastern limb. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ...

References

• Magnitudes of Thirty-six of the Minor Planets for the first day of each month of the year 1857, N. Pogson, MNRAS 17 pp 12 1856 in which Pogson first introduced his magnitude system