Get it on Google Play
New! Download Unionpedia on your Android™ device!
Faster access than browser!
New! Save your concepts! » Create account

40 Eridani is a triple star system less than 16.5 light years away from Earth, in the constellation Eridanus. [1]

47 relations: Aitken Double Star Catalogue, Alpha Serpentis, Apparent magnitude, Astronomical unit, Bayer designation, Bright Star Catalogue, Catalog of Components of Double and Multiple Stars, Centre de données astronomiques de Strasbourg, Circumstellar habitable zone, Durchmusterung, Dwarf star, Earth, Epoch (astronomy), Eridanus (constellation), Flamsteed designation, Flare star, Friedrich Georg Wilhelm von Struve, Gliese Catalogue of Nearby Stars, Henry Draper Catalogue, Hercules (constellation), Hipparcos, Kepler's laws of planetary motion, Light-year, Main sequence, Metallicity, Minute and second of arc, Orbital eccentricity, Otto Wilhelm von Struve, Parsec, Procyon, Red dwarf, Serpens, Sirius, Smithsonian Astrophysical Observatory Star Catalog, Star catalogue, Star chart, Star system, Stefan–Boltzmann constant, Stellar classification, Van Maanen 2, Variable star, Variable star designation, Venus, White dwarf, William Herschel, X-ray, 1 petametre.

Aitken Double Star Catalogue

The Aitken Double Star Catalogue, or ADS, is a star catalogue of double stars.

New!!: 40 Eridani and Aitken Double Star Catalogue · See more »

Alpha Serpentis

Alpha Serpentis (α Serpentis, α Ser) is a double star in the head (Serpens Caput) of the equatorial constellation Serpens.

New!!: 40 Eridani and Alpha Serpentis · See more »

Apparent magnitude

The apparent magnitude (m) of a celestial object is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere.

New!!: 40 Eridani and Apparent magnitude · See more »

Astronomical unit

The astronomical unit (symbol au, AU or ua) is a unit of length, roughly the distance from the Earth to the Sun.

New!!: 40 Eridani and Astronomical unit · See more »

Bayer designation

A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name.

New!!: 40 Eridani and Bayer designation · See more »

Bright Star Catalogue

The Bright Star Catalogue, also known as the Yale Catalogue of Bright Stars or Yale Bright Star Catalogue, is a star catalogue that lists all stars of stellar magnitude 6.5 or brighter, which is roughly every star visible to the naked eye from Earth.

New!!: 40 Eridani and Bright Star Catalogue · See more »

Catalog of Components of Double and Multiple Stars

The Catalog of Components of Double and Multiple Stars, or CCDM, is an astrometric star catalogue of double and multiple stars.

New!!: 40 Eridani and Catalog of Components of Double and Multiple Stars · See more »

Centre de données astronomiques de Strasbourg

The Centre de données astronomiques de Strasbourg (CDS; English translation: Strasbourg Astronomical Data Center) is a data hub which collects and distributes astronomical information.

New!!: 40 Eridani and Centre de données astronomiques de Strasbourg · See more »

Circumstellar habitable zone

In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the region around a star within which planetary-mass objects with sufficient atmospheric pressure can support liquid water at their surfaces.

New!!: 40 Eridani and Circumstellar habitable zone · See more »


In astronomy, Durchmusterung or Bonner Durchmusterung (BD), is the comprehensive astrometric star catalogue of the whole sky, compiled by the Bonn Observatory (Germany) from 1859 to 1903.

New!!: 40 Eridani and Durchmusterung · See more »

Dwarf star

The term dwarf star refers to a variety of distinct classes of stars.

New!!: 40 Eridani and Dwarf star · See more »


Earth (also the world, in Greek: Gaia, or in Latin: Terra), is the third planet from the Sun, the densest planet in the Solar System, the largest of the Solar System's four terrestrial planets, and the only astronomical object known to accommodate life.

New!!: 40 Eridani and Earth · See more »

Epoch (astronomy)

In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.

New!!: 40 Eridani and Epoch (astronomy) · See more »

Eridanus (constellation)

Eridanus is a constellation in the southern hemisphere.

New!!: 40 Eridani and Eridanus (constellation) · See more »

Flamsteed designation

Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek and Roman letters.

New!!: 40 Eridani and Flamsteed designation · See more »

Flare star

A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes.

New!!: 40 Eridani and Flare star · See more »

Friedrich Georg Wilhelm von Struve

Friedrich Georg Wilhelm von Struve (Vasily Yakovlevich Struve) (April 15, 1793 – November 23, 1864 (Julian calendar: November 11)) was a German astronomer from a famous dynasty.

New!!: 40 Eridani and Friedrich Georg Wilhelm von Struve · See more »

Gliese Catalogue of Nearby Stars

The Gliese Catalogue of Nearby Stars is a modern star catalogue of stars located within 25 parsecs (81.54 ly) of the Earth.

New!!: 40 Eridani and Gliese Catalogue of Nearby Stars · See more »

Henry Draper Catalogue

The Henry Draper Catalogue (HD) is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the Henry Draper Extension (HDE), published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the Henry Draper Extension Charts (HDEC), published from 1937 to 1949 in the form of charts, which gave classifications for 86,933 more stars.

New!!: 40 Eridani and Henry Draper Catalogue · See more »

Hercules (constellation)

Hercules is a constellation named after Hercules, the Roman mythological hero adapted from the Greek hero Heracles.

New!!: 40 Eridani and Hercules (constellation) · See more »


Hipparcos was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993.

New!!: 40 Eridani and Hipparcos · See more »

Kepler's laws of planetary motion

In astronomy, Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun.

New!!: 40 Eridani and Kepler's laws of planetary motion · See more »


A light-year (abbreviation: ly), sometimes written light year, is a unit of length used informally to express astronomical distances.

New!!: 40 Eridani and Light-year · See more »

Main sequence

In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness.

New!!: 40 Eridani and Main sequence · See more »


In astronomy and physical cosmology, the metallicity or Z, is the fraction of mass of a star or other kind of astronomical object, beyond hydrogen (X) and helium (Y).

New!!: 40 Eridani and Metallicity · See more »

Minute and second of arc

A minute of arc (MOA), arcminute (arcmin) or minute arc is a unit of angular measurement equal to one-sixtieth of one degree.

New!!: 40 Eridani and Minute and second of arc · See more »

Orbital eccentricity

The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle.

New!!: 40 Eridani and Orbital eccentricity · See more »

Otto Wilhelm von Struve

Otto Wilhelm von Struve (May 7, 1819 (Julian calendar: April 25) – April 14, 1905) was a Russian astronomer.

New!!: 40 Eridani and Otto Wilhelm von Struve · See more »


A parsec (symbol: pc) is a unit of length used to measure the astronomically large distances to objects outside the Solar System.

New!!: 40 Eridani and Parsec · See more »


Procyon (α CMi, α Canis Minoris, Alpha Canis Minoris) is the brightest star in the constellation Canis Minor.

New!!: 40 Eridani and Procyon · See more »

Red dwarf

A red dwarf is a small and relatively cool star on the main sequence, either late K or M spectral type.

New!!: 40 Eridani and Red dwarf · See more »


Serpens ("the Serpent", Greek Ὄφις) is a constellation of the northern hemisphere.

New!!: 40 Eridani and Serpens · See more »


Sirius is the brightest star (in fact, a star system) in the Earth's night sky.

New!!: 40 Eridani and Sirius · See more »

Smithsonian Astrophysical Observatory Star Catalog

The Smithsonian Astrophysical Observatory Star Catalog is an astrometric star catalogue.

New!!: 40 Eridani and Smithsonian Astrophysical Observatory Star Catalog · See more »

Star catalogue

A star catalogue, or star catalog, is an astronomical catalogue that lists stars.

New!!: 40 Eridani and Star catalogue · See more »

Star chart

A star chart or star map is a map of the night sky.

New!!: 40 Eridani and Star chart · See more »

Star system

A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction.

New!!: 40 Eridani and Star system · See more »

Stefan–Boltzmann constant

The Stefan–Boltzmann constant (also Stefan's constant), a physical constant denoted by the Greek letter ''σ''(sigma), is the constant of proportionality in the Stefan–Boltzmann law: "the total intensity (physics) radiated over all wavelengths increases as the temperature increases", of a black body which is proportional to the fourth power of the thermodynamic temperature.

New!!: 40 Eridani and Stefan–Boltzmann constant · See more »

Stellar classification

In astronomy, stellar classification is the classification of stars based on their spectral characteristics.

New!!: 40 Eridani and Stellar classification · See more »

Van Maanen 2

Van Maanen 2 (van Maanen's Star) is a white dwarf.

New!!: 40 Eridani and Van Maanen 2 · See more »

Variable star

A variable star is a star whose brightness as seen from Earth (its apparent magnitude) fluctuates.

New!!: 40 Eridani and Variable star · See more »

Variable star designation

Variable stars are designated using a variation on the Bayer designation format of an identifying label (as described below) combined with the Latin genitive of the name of the constellation in which the star lies.

New!!: 40 Eridani and Variable star designation · See more »


Venus is the second planet from the Sun, orbiting it every 224.7 Earth days.

New!!: 40 Eridani and Venus · See more »

White dwarf

A white dwarf, also called a degenerate dwarf, is a stellar remnant composed mostly of electron-degenerate matter.

New!!: 40 Eridani and White dwarf · See more »

William Herschel

Frederick William Herschel, KH, FRS (German: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer, composer, and brother of Caroline Herschel.

New!!: 40 Eridani and William Herschel · See more »


X-radiation (composed of X-rays) is a form of electromagnetic radiation.

New!!: 40 Eridani and X-ray · See more »

1 petametre

To help compare different distances this page lists lengths starting at 1015 m (1 Pm or 1,000,000 million km or 6685 astronomical units (AU) or 0.11 light years).

New!!: 40 Eridani and 1 petametre · See more »

Redirects here:

40 Eri, 40 Eri A, 40 Eri B, 40 Eri C, 40 Eridani A, 40 Eridani B, 40 Eridani C, 40 Eridani-A, 40 Eridani-B, 40 Eridani-C, ADS 3093, ADS 3093A, ADS 3093B, ADS 3093C, CCDM J04153-0739, CCDM J04153-0739A, CCDM J04153-0739B, CCDM J04153-0739C, DY Eri, DY Eridani, G 160-060, GCTP 945, GJ 166, GJ 166 A, GJ 166 B, GJ 166 C, HD 26965, HD 26976, HIP 19849, HR 1325, Keid, LHS 23, LHS 24, LHS 25, LTT 1907, LTT 1908, LTT 1909, Omicron-2 Eridani, Omicron2 Eridani, SAO 131063, SAO 131065, STF 518, STF 518A, STF 518B, STF 518C, WD 0413-077, WD 0413−077, Ο2 Eri.


[1] https://en.wikipedia.org/wiki/40_Eridani

Hey! We are on Facebook now! »