Sextans Constellation: The Ultimate Guide
Sextans (The Sextant)
Sextans is one of the constellations located in the southern celestial hemisphere. Its name comes from the Latin "Sextant," a measuring tool that astronomers used in the past to measure the position of stars.
Sextans is one of the 88 modern constellations, so its name is not derived from a myth, history, or ancient mythology like the most famous constellations.
The location of the constellation Sextans is essentially in the southern hemisphere and is most visible during spring in the northern hemisphere and autumn in the southern hemisphere.
The constellation Sextans covers an area of 314 square degrees. It ranks 47th in size among the 88 constellations in the night sky.
The brightest star in the Sextans constellation is Alpha Sextantis (α Sex/α Sextantis/15 Sextantis), with an apparent magnitude of +4.48.
The constellation Sextans is home to deep-sky objects, mainly galaxies.
There are no occurrences of meteor showers within the boundaries of the constellation.
The Mythology And History Of The Sextans Constellation
Sextans is classified as one of the 88 modern constellations, meaning that it has no associated history in ancient Western cultures because it was not visible in those regions.
In the case of Greek culture, when Ptolemy wrote the Almagest, it did not mention the constellation Sextans, nor does it appear on the celestial maps of the time.
It is known that Sextans is one of the faintest constellations and that most of its stars cannot be seen with the naked eye, so it was necessary to wait for telescopes to be invented to see it.
Early Modern Period
Sextans was introduced in 1687 by Polish astronomer Johannes Hevelius (Jan Heweliusz), who originally named it Sextans (Sextant) to commemorate the importance of the measuring instruments he used to calculate the position of stars.
Nowadays
In 1922 the International Astronomical Association added the constellation Sextans to the 88 official night sky constellations. Since then, it has not undergone significant modifications in its boundaries.
Sextans currently covers an area of 314 square degrees. It ranks 47th in size among the 88 constellations in the night sky.
How To Find The Sextans Constellation?
Visibility By Region
Sextans reside in the Southern Hemisphere's second quadrant (SQ2) between latitudes 80° N and 90° S, which means that we can see the constellation Sextans in the night sky from all countries of the world.
Sextans is visible in America, Europe, Africa, Australia, Asia, and Antarctica.
Visibility By Season
The constellation Sextans is in the southern celestial hemisphere. April is the best month to visualize it.
Sextans' constellation is visible during spring in the northern hemisphere and autumn in the southern hemisphere.
Finding Sextans Constellation
Sextans is a small and faint constellation, but it lies in the middle of two vast and important constellations, Hydra and Leo.
The easiest way to locate the constellation Sextans is by drawing an imaginary straight line from the star Alphard in the constellation Hydra to the star Denebola in the constellation Leo. The constellation Sextans is halfway between the two.
Related Constellations
The constellations bordering Sextans are Leo, Hydra, and Crater.
In addition, Sextans belongs to the family of constellations Hercules; these include Aquila, Ara, Centaurus, Corona Australis, Corvus, Crater, Crux, Cygnus, Hercules, Hydra, Lupus, Lyra, Ophiuchus, Sagitta, Scutum, Serpens, Triangulum Australe and Vulpecula.
Stars in Sextans Constellation
The constellation Sextans officially contains 38 stars, of which 4 form the central figure of the constellation; these are Alpha Sextantis, Beta Sextantis, Gamma Sextantis, and Delta Sextantis.
Alpha Sextantis (α Sex / α Sextantis / 15 Sextantis)
It is the brightest star in the constellation Sextans, with an apparent magnitude of +4.48. It is 287 light-years from the Solar System.
Alpha Sextantis is classified as a white giant of spectral type A0III, although its diameter is only 3.8 times larger than the Sun. It has an effective temperature of 9900 K and, with a mass three times greater than the solar mass; its luminosity is equivalent to that of 122 suns.
Gamma Sextantis (γ Sex / γ Sextantis / 8 Sextantis)
It is the second brightest star in the constellation Sextans with an apparent magnitude of +5.09. It is 277 light-years from the earth.
This is a triple star made up of Gamma Sextantis A, Gamma Sextantis B, and Gamma Sextantis C.
Other Sextans Stars:
- β Sextantis: A variable star Alpha2 Canum Venaticorum whose brightness ranges from magnitude 5.00 to 5.10.
- δ Sextantis: A bluish-white star of magnitude 5.18.
- ε Sextantis: A yellow giant star of magnitude 5.25.
- 4 Sextantis: Spectroscopic binary star of magnitude 6.24.
- 17 Sextantis: Star with envelope whose age is estimated at only 300,000 years.
- 20 Sextantis: Yellow dwarf star of magnitude 7.22.
- 24 Sextantis: An orange subgiant star of magnitude 6.44 where two extrasolar planets have been discovered.
- 33 Sextantis: Yellow subgiant star; has magnitude 6.26.
- And Sextantis: W-type eclipsing binary star Ursae Majoris.
- SS Sextantis (25 Sextantis): A variable star Alpha2 Canum Venaticorum of magnitude 5.93 shows a slight variation in brightness of 0.04 magnitudes.
- LHS 292: Red dwarf star and shining star in the vicinity of the Solar System.
- Gliese 382, Gliese 390, and Gliese 393: All three are red dwarfs of magnitude 9.26, 10.14, and 9.63, respectively.
- BD-08 2823: Orange dwarf star that houses a planetary system.
- WD 0942+021: A faint white dwarf star located about 80 light-years away.
Deep Sky Objects
Sextans is also home to several deep-sky objects. Deep-sky objects often mean star clusters, nebulae (interstellar cloud bodies), or galaxies.
In the case of Sextans, because it is a small constellation that has very few deep-sky objects, it contains mainly galaxies; some of the most notable of them are:
Spindle galaxy or NGC 3115
It is a lenticular galaxy in the constellation Sextans 32 million light-years away, discovered by astronomer William Herschel on February 22, 1787. It is the most notable deep-sky object in the constellation Sextans.
It is the fourth galaxy where a supermassive black hole has been found. 1 It was one of the first discovered to be exceptionally massive compared to the rest of the galaxy. It is close enough to see the effects of the black hole on nearby stars.
Sextans Dwarf Galaxy or SexDEG
It is a satellite spheroidal dwarf galaxy of the Milky Way, which has a diameter of approximately 4000 light-years and is currently 280,000 light-years from Earth.
It has a redshift when moving away from us at a speed of 224 km/s. It is an ancient galaxy that contains few metals, that is, elements heavier than hydrogen and helium.
Conclusions
- Sextans is a constellation located primarily in the southern hemisphere. Its name comes from the Latin "Sextant," a measuring tool that astronomers used in the past to measure the position of stars.
- The constellation Sextans is located between 80° N and 90° S. The best month to observe the constellation is April.
- The easiest way to locate the constellation Sextans is by drawing an imaginary straight line from the star Alphard in the constellation Hydra to the star Denebola in the constellation Leo. The constellation Sextans is halfway between the two.
- The brightest star in the constellation Sextans is Alpha Sextantis (α Sex/α Sextantis /15 Sextantis), with an apparent magnitude of +4.48.
- The most notable deep sky body of the Sextans constellation is The Galaxy NGC 3115.