Lacaille 8760
Encyclopedia
Lacaille 8760 is a red dwarf
star
in the constellation
Microscopium
, the microscope
. Although it is slightly too faint to be seen without a telescope
, it is one of the nearest stars to the Sun at about 12.9 light years distance. It was originally listed in a 1763 catalog that was published posthumously by the French
Abbé Nicolas Louis de Lacaille
. He observed it in the southern sky while working from an observatory at the Cape of Good Hope
.
In the past Lacaille 8760 has been classified anywhere from spectral class K7 down to M2. In 1979 the Irish
astronomer Patrick Byrne discovered that it is a flare star
, and it was given the variable star designation AX Microscopii. As a flare star it is relatively quiet, only erupting on average less than once per day.
Lacaille 8760 orbits around the galaxy in an elliptical orbit with a relatively high ellipticity of 0.23. Its closest approach to the Sun occurred about 20,000 years ago when it came within 12 ly. Due to its low mass (60 % of our Sun), it has an expected lifespan of about , 7 times more than for the Sun.
Despite efforts by astronomers, thus far no planets have been detected in orbit around this star.
Although Lacaille 8760 is the brightest red dwarf star visible in the night sky, it's still too dim to be seen with the naked eye. It is also one of the largest and brightest red dwarf stars known, with about 60% the mass and 51% the radius of the Sun.
Red dwarf
According to the Hertzsprung-Russell diagram, a red dwarf star is a small and relatively cool star, of the main sequence, either late K or M spectral type....
star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Microscopium
Microscopium
Microscopium is a small constellation in the southern sky, created in the 18th century by Nicolas Louis de Lacaille. Its name is Latin for microscope. Its stars are very faint and hardly visible from most of the non-tropical northern hemisphere.-References:...
, the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
. Although it is slightly too faint to be seen without a telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
, it is one of the nearest stars to the Sun at about 12.9 light years distance. It was originally listed in a 1763 catalog that was published posthumously by the 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...
Abbé Nicolas Louis de Lacaille
Nicolas Louis de Lacaille
Abbé Nicolas Louis de Lacaille was a French astronomer.He is noted for his catalogue of nearly 10,000 southern stars, including 42 nebulous objects. This catalogue, called Coelum Australe Stelliferum, was published posthumously in 1763. It introduced 14 new constellations which have since become...
. He observed it in the southern sky while working from an observatory at the Cape of Good Hope
Cape of Good Hope
The Cape of Good Hope is a rocky headland on the Atlantic coast of the Cape Peninsula, South Africa.There is a misconception that the Cape of Good Hope is the southern tip of Africa, because it was once believed to be the dividing point between the Atlantic and Indian Oceans. In fact, the...
.
In the past Lacaille 8760 has been classified anywhere from spectral class K7 down to M2. In 1979 the Irish
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
astronomer Patrick Byrne discovered that it is a flare star
Flare star
A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection in the atmospheres of the stars. The brightness increase is...
, and it was given the variable star designation AX Microscopii. As a flare star it is relatively quiet, only erupting on average less than once per day.
Lacaille 8760 orbits around the galaxy in an elliptical orbit with a relatively high ellipticity of 0.23. Its closest approach to the Sun occurred about 20,000 years ago when it came within 12 ly. Due to its low mass (60 % of our Sun), it has an expected lifespan of about , 7 times more than for the Sun.
Despite efforts by astronomers, thus far no planets have been detected in orbit around this star.
Although Lacaille 8760 is the brightest red dwarf star visible in the night sky, it's still too dim to be seen with the naked eye. It is also one of the largest and brightest red dwarf stars known, with about 60% the mass and 51% the radius of the Sun.