Alpha Mensae
Encyclopedia
Alpha Mensae is the brightest star in the constellation
Mensa
. At a magnitude of 5.09, it is the dimmest lucida (a constellation's brightest star) in all the heavens. It is a main sequence
dwarf star only slightly smaller and cooler in temperature than the Sun
. Due to its declination
, on Earth
it is best visible from higher latitudes of the southern hemisphere
, yet can also be seen, though low in the sky, from just north of the Equator when near its daily arc's highest point, the culmination.
Alpha Mensae has a relatively high proper motion
across the sky, and it is located about 33 light years distant from the Sun
. No planetary companions have yet been discovered around it. It has a red dwarf companion star at a distance of 3.05 arcseconds (a projected separation of roughly 30 AU).
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....
Mensa
Mensa (constellation)
Mensa is a constellation in the southern sky, created in the 18th century. Its name is Latin for table. It covers a keystone-shaped wedge of sky stretching from approximately 4h to 7.5h of right ascension, and −71 to −85.5 degrees of declination. Other than the south polar constellation...
. At a magnitude of 5.09, it is the dimmest lucida (a constellation's brightest star) in all the heavens. It is a main sequence
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
dwarf star only slightly smaller and cooler in temperature than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. Due to its declination
Declination
In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...
, on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
it is best visible from higher latitudes of the southern hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
, yet can also be seen, though low in the sky, from just north of the Equator when near its daily arc's highest point, the culmination.
Alpha Mensae has a relatively high proper motion
Proper motion
The proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...
across the sky, and it is located about 33 light years distant from the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. No planetary companions have yet been discovered around it. It has a red dwarf companion star at a distance of 3.05 arcseconds (a projected separation of roughly 30 AU).