Microscopium Constellation


Microscopium constellation lies in the southern hemisphere. It was introduced by the French astronomer Nicolas Louis de Lacaille in the 18th century.

The constellation is not associated with any myths. It represents the microscope. It is a small, faint constellation that is hard to see from the northern latitudes.

The brightest stars in Microscopium are only of fifth magnitude and the constellation cannot be seen without binoculars in less than ideal observing conditions.

Microscopium lies to the south of Capricornus, between the constellations Piscis Austrinus and Sagittarius.

It does not have any bright deep sky objects.

FACTS, LOCATION & MAP

microscopium constellation,microscopium stars,star map,location
Microscopium Constellation Map, by IAU and Sky&Telescope magazine

Microscopium is the 66th constellation in size, occupying an area of 210 square degrees.

It is located in the fourth quadrant of the southern hemisphere (SQ4) and can be seen at latitudes between +45° and -90°.

The neighboring constellations are Capricornus, Grus, Indus, Piscis Austrinus, Sagittarius and Telescopium.

Microscopium contains one star with known planets and has no Messier objects.

The brightest star in the constellation is Gamma Micoscopii, with an apparent visual magnitude of 4.67.

There are no meteor showers associated with the constellation.

Microscopium belongs to the Lacaille family of constellations, along with Antlia, Caelum, Circinus, Fornax, Horologium, Mensa, Norma, Octans, Pictor, Reticulum, Sculptor and Telescopium.


STORY

Microscopium constellation was created by the French astronomer Nicolas Louis de Lacaille in 1751-1752.

He named it after an early type of compound microscope, one that used more than one lens and was widely used in the 18th century.

Lacaille described the constellation as depicting “a tube above a square box.”

The official boundaries of the constellation as it is today were set by the Belgian astronomer Eugène Delporte in 1930.

MAJOR STARS IN MICROSCOPIUM

γ Microscopii (Gamma Microscopii)

Gamma Microscopii is the brightest star in Microscopium. It has an apparent visual magnitude of 4.68 and is approximately 229 light years distant from Earth. It is a yellow giant star with the stellar classification of G6 III. It has a visual companion with an apparent magnitude of 13.7 at an angular separation of 26 arcseconds.

Gamma Microscopii has 2.5 times the Sun’s mass, 10 times the solar radius, and is about 64 times more luminous than the Sun.

ε Microscopii (Epsilon Microscopii)

Epsilon Microscopii is the second brightest star in Microscopium. It has a visual magnitude of 4.72 and is approximately 165 light years distant from the solar system. It is a white main sequence dwarf with the stellar classification A1V.

θ Microscopii (Theta Microscopii)

Theta Microscopii consists of a wide double star, Theta-1 Microscopii and Theta-2 Microscopii, which can both be seen without binoculars. Both components belong to the spectral class A and are white magnetic spectrum variable stars that have strong metallic lines.

Theta Microscopii is the third brightest star in the constellation and marks the microscope’s specimen slide. It has an apparent visual magnitude of 4.81 and is approximately 186 light years distant from the Sun. Theta-1 Microscopii is classified as an Alpha-2 Canum Venaticorum type variable.

Alpha Microscopii is a spectral type G7III yellow giant star in a double system. Image: Centre de Données astronomiques de Strasbourg
Alpha Microscopii is a spectral type G7III yellow giant star in a double system. Image: Centre de Données astronomiques de Strasbourg

α Microscopii (Alpha Microscopii)

Alpha Microscopii is only the fourth brightest star in the constellation. It is a variable star with an apparent magnitude that ranges from 4.88 to 4.94. The star is approximately 380 light years distant from Earth.

Alpha Microscopii is a yellow giant belonging to the stellar class G7III. It has a visual companion with an apparent magnitude of 10 at a separation of 20.4 seconds of arc. The companion can be seen in a small telescope.

Lacaille 8760 (AX Microscopii)

Lacaille 8760 is one of the nearest stars to the Sun. It is only 12.87 light years distant and has an apparent visual magnitude of 6.67, too faint to be seen without binoculars.

It is classified as a flare star and has the variable designation AX Microscopii. The star only erupts less than once a day on average.

It has a mass about 60 percent that of the Sun and a radius 0.51 times solar. It is one of the largest and brightest red dwarfs known.

Lacaille 8760 has the stellar classification M0 Ve. It was discovered by Nicolas Louis de Lacaille from the Cape of Good Hope in South Africa in the early 1750s.

The star was closest to the Sun about 20,000 years ago, when it came within 12 light years.

au microscopii,flare star,microscopium constellation
This is an artist’s impression of the view from the vicinity of a hypothetical terrestrial planet and moon orbiting the red dwarf star AU Microscopii. The relatively newborn 12 million year-old star is surrounded by a very dusty disk of debris from the collision of comets, asteroids, and planetissimals swirling around the young star. Though no planets have been discovered around the star, the disk is strong circumstantial evidence for planets. Not only is it dusty, but also it is warped, possibly by the pull of one or more planets. In this view the glow of starlight reflecting off the disk creates a broad lane across the sky because the planet is in the disk’s plane. Similarly, from Earth we see light reflected from interplanetary dust as the zodiacal light (though it is 1/10,000th as dusty as the AU Microcsopii disk). The star AU Microscopiii is 32 light-years from Earth. From this distance, familiar constellations are still recognizable. In the background, the Beehive cluster in Cancer the Crab is seen. Our Sun appears as a bright star in Cancer. Image: NASA, ESA, G. Bacon (STScI)

AU Microscopii

AU Microscopii is another variable star in Microscopium. It is a flare star with the stellar classification of M1 Ve.

It has an apparent magnitude of 8.73 and is 32.3 light years distant from the solar system. It is too faint to be seen with the naked eye.

The star has a circumstellar dust disk about 200 astronomical units in radius and is believed to be only 12 million years old.

It is a red dwarf with a mass 0.31 times that of the Sun and a radius 0.84 times solar. It has only 9 percent of the Sun’s luminosity.

AU Microscopii is a member of the Beta Pictoris Moving Group of stars.

BO Microscopii

BO Microscopii is another flare star in Microscopium. It is an orange star with the stellar classification of K3Ve, approximately 170 light years distant from Earth. It has a visual magnitude of 9.39. It has a mass 82 percent that of the Sun and 1.06 times the solar radius.

The star is sometimes called “Speedy Mic” because it is a very fast spinner. It has a projected rotational velocity of 135 km/s and completes a rotation every 0.380 days.

WASP-7 (HD 197286)

WASP-7 is a yellow-white main sequence dwarf with the stellar classification of F5V. It has an apparent magnitude of 9.51 and is approximately 456 light years distant from the solar system. The star can be seen through a small telescope. It has a mass 1.28 times that of the Sun and 1.236 times the Sun’s radius.

An extrasolar planet, WASP-7b, was disovered orbiting the star in 2008. The planet is a hot Jupiter, with a mass 0.96 times that of Jupiter, and it orbits the star with a period of 4.954658 days.

DEEP SKY OBJECTS IN MICROSCOPIUM

barred spiral galaxy,microscopium
NGC 6925, image: Wikisky

NGC 6925

NGC 6925 is a barred spiral galaxy in Microscopium.

It has an apparent visual magnitude of 11.3.

The galaxy is lens-shaped and appears almost edge-on when seen from Earth.

It can be found 3.7 degrees to the west-northwest of Alpha Microscopii.

It was discovered by the English astronomer John Herschel in July 1834.

spiral galaxy
NGC 6923, image: Wikisky

A Type IIb supernova, SN 2011ei, was observed in the galaxy in 2011.

NGC 6923

NGC 6923 is another spiral galaxy in Microscopium.

It has an apparent visual magnitude of 12.2 and lies approximately 36.437 million parsecs from Earth.

Like NGC 6925, the galaxy was discovered by John Herschel in the summer of 1834.