Irma (
minor planet designation
A formal minor-planet designation is, in its final form, a number–name combination given to a minor planet (asteroid, centaur, trans-Neptunian object and dwarf planet but not comet). Such designation always features a leading number (catalog or ...
: 177 Irma) is a fairly large and dark
main belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
. It was discovered by the French brothers
Paul Henry and Prosper Henry
Paul-Pierre Henry (Paul Henry) (21 August 1848 – 4 January 1905) and his brother Prosper-Mathieu Henry (Prosper Henry) (10 December 1849 – 25 July 1903) were French opticians and astronomers.
They made refracting telescopes and instruments ...
on November 5, 1877. Paul was credited for this discovery. The meaning of the name Irma is unknown.
observations of this asteroid at the Organ Mesa Observatory in
Las Cruces, New Mexico
Las Cruces (; "the crosses") is the second-largest city in the U.S. state of New Mexico and the seat of Doña Ana County. As of the 2020 census the population was 111,385. Las Cruces is the largest city in both Doña Ana County and southern New ...
in 2011 gave a
light curve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...
with a period of 13.856 ± 0.001 hours and a brightness variation of 0.30 ± 0.03 in
magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
.
References
External links
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Background asteroids
Irma
Irma
C-type asteroids (Tholen)
Ch-type asteroids (SMASS)
18771105
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