Hydra Constellation: The Ultimate Guide
Hydra (The multi-headed water snake)
Hydra is the largest constellation of all and is in the southern celestial hemisphere. The constellation's name comes from Greek mythology, where Hydra is the name of a creature shaped like an aquatic snake with many heads.
Hydra only occupies an area of 1303 square grades, so it is the largest constellation of the 88 that there are official; however, it does not have stars of the first magnitude, so it is a faint constellation.
The location of the constellation Hydra is essentially in the southern hemisphere. Still, it is possible to visualize it in some northern hemisphere countries, and we can find it in the night sky throughout the spring.
The brightest star in the constellation Hydra is Alfard (Alphard α Hya / α Hydrae / 30 Hya), with an apparent magnitude of +1.99.
The constellation Hydra is home to deep-sky objects such as nebulae and star clusters.
In addition, within the boundaries of the constellation Hydra, there are occurrences of an essential meteor shower.
The Mythology And History Of The Hydra Constellation
Ancient Babylon
In the Babylonian astronomy of antiquity, there was a tablet called MUL. APIN deals with many diverse aspects of astronomy and astrology.
In this tablet, a constellation called (MUL. DINGIR. MUŠ) "snake in Babylonian" presents the coordinates and characteristics of what we know today as the constellation Hydra.
It is thought that this description corresponds precisely to this constellation and would later be adopted by other cultures.
Greek Mythology
In the mythology of ancient Greece, there are many myths with which the constellation of Hydra is associated. But the most famous of all is from the beast Hydra.
In the myth, Hydra was a gigantic aquatic creature in the shape of a snake that could regenerate, and every time one head was cut off, two grew in its place.
Hercules would be in charge of killing this creature as part of his 12 works later in Greek culture; he would associate this creature with a constellation.
Early Modern Period
During the sixteenth century, the constellation Hydra was of great importance for the navigation of ships. Since that extends along the entire celestial equator, it was possible to use it as a guide to determine the passage of the hours during the night when it was impossible to see other northern hemisphere stars.
In other cultures of South America, such as the Inca, the constellation Hydra appears as a giant snake that covers the heavens.
Nowadays
In the 90s, it was proposed to modify the boundaries of the constellation Hydra since it was too elongated. Still, the changes were not considered, and it is currently the most prominent and longest constellation of all.
It has also been essential for scientific research because deep-sky objects are significant for astronomy within its limits.
How To Find The Hydra Constellation?
Visibility By Region
Hydra resides in the second quadrant of the Southern Hemisphere (SQ2) at latitudes between 54° N and 83° S, which means that we can see the constellation in the night sky from all countries of the southern hemisphere. Still, it is impossible to see it from all northern hemisphere countries.
Hydra is visible in America, Europe, Asia, Australia, and Antarctica.
Hydra is not visible in areas above 54° N latitude, such as Denmark, Lithuania, Norway, Sweden, Finland, Greenland, northern Canada, and Alaska.
Visibility By Season
Hydra is a constellation close to the celestial equator, so it is visible almost all year round; however, the best month to visualize it is in April.
Hydra is visible mainly during spring in the northern hemisphere; it stays longer in the night sky.
Finding Hydra Constellation
Hydra is located near the celestial equator, so you will have to turn your gaze to the south in the northern hemisphere.
One way to locate the Hydra constellation is by finding its brightest star Alphard, which is in the part of the constellation closest to the constellation Sextans.
To find Hydra, you can contact the constellation Cancer to find Hydra since both constellations are very close.
The easiest way to locate the constellation Hydra is by drawing an imaginary straight line from the constellation Leo to the constellation Centaurus; in the middle of the two, you will find the constellation Hydra.
Related Constellations
The constellations bordering Hydra are Antlia, Cancer, Canis Minor, Centaurus, Corvus, Crater, Leo, Libra, Lupus (corner), Monoceros, Puppis, Pyxis, Sextans, and Virgo.
In addition, the constellation Hydra belongs to the Hercules family of constellations, including Aquila, Ara, Centaurus, Corona Australis, Corvus, Crater, Crux, Cygnus, Hercules, Lupus, Lyra, Ophiuchus, Sagitta, Scutum, Sextans, Serpens, Triangulum Australe, and Vulpecula.
Stars in Hydra Constellation
The constellation Hydra officially contains 238 stars, of which 16 form the central figure of the constellation, these are Alphard, Gamma Hydrae, Hydrobius, Nu Hydrae, Pi Hydrae, Ashlesha, Xi Hydrae, Lambda Hydrae, Mu Hydrae, Theta Hydrae, Iota Hydrae, Upsilon-1 Hydrae, Delta Hydrae, Beta Hydrae, Eta Hydrae, and Minchir.
Alfard (Alphard / α Hya / α Hydrae / 30 Hya)
Alfard is the most important star in the constellation Hydra, with an apparent magnitude of +1.99. It is at a distance of 177 light-years from the earth and consists of an orange giant of spectral type K3II-III with an effective temperature of 4000 K.
Other Hydra Stars:
- β Hydrae: Binary star of magnitude 4.29 whose components are separated 1.7 arcseconds.
- δ Hydrae: A white star of magnitude 4.14.
- ε Hydrae (Ashlesha): Multiple star system of joint magnitude 3.38.
- η Hydrae: A bluish-white star of magnitude 4.30.
- θ Hydrae: A blue-white main-sequence star of magnitude 3.88.
- ι Hydrae (Ukdah): Orange giant of magnitude 3.91.
- λ Hydrae: An orange giant of magnitude 3.61 rich in cyanogen.
- μ Hydrae: Orange giant star, its magnitude is 3.83.
- ν Hydrae: An orange giant star of magnitude 3.11.
- ξ Hydrae: A giant star studied in the field of astroseismology; its surface, like that of the Sun, moves from top to bottom, producing sound waves.
- π Hydrae: An orange giant star of magnitude 3.26.
- σ Hydrae (Minchir or Al Minliar al Shuja): Orange giant star of magnitude 4.45.
- τ1 Hydrae: White-yellow dwarf stars are hotter and luminous than the Sun.
- υ1 Hydrae (Zhang): Giant yellow star of magnitude 4.11 that has as a companion a brown dwarf.
- ω Hydrae: Orange supergiant star of magnitude 5.00.
- C Hydrae (30 Monocerotis): A white star with two different dust belts.
- 2 Sextantis: An orange giant star of magnitude 4.69; despite its name, it is in the constellation of Hydra.
- 3 Hydrae (HV Hydrae): A peculiar and variable star Alfa2 Canum Venaticorum.
- 9 Hydrae: An orange giant star of magnitude 4.87.
- 12 Hydrae (D Hydrae): Yellow giant star of magnitude 4,32.
- 21 Hydrae (KW Hydrae): Eclipsing binary star of magnitude 6.10.
- 27 Hydrae: Multiple stars formed after two binaries; the separation is 229 arcseconds.
Deep Sky Objects
Hydra is also known as the drowning of various deep sky objects. Deep-sky objects often mean star clusters, nebulae (interstellar cloud bodies), or galaxies.
In the case of Hydra, it is rich in galaxies, nebulae, and star clusters, being one of the constellations with the most incredible diversity of deep-sky bodies.
Austral Grinder (M83 / NGC 5236)
It is a galaxy known as the Southern Grinder; it is an example of a starburst galaxy where the rate of star birth is much higher than that of a typical galaxy.
The Southern Grinder is the most remarkable deep-sky object in the constellation Hydra with an apparent magnitude of +7.5, located at a distance of 14 million light-years.
Other Notable Deep-sky Objects In Hydra:
- M48: It is an open cluster that is observable with the naked eye and good atmospheric conditions.
- M68: It is a globular cluster located in an unusual place for these objects since it is in the hemisphere opposite the galactic center. It contains about 250 giant stars of absolute magnitude less than zero, with its brightest star being 12.6.
- NGC 3109: It is an irregular galaxy member of our Local Group, one of its poorest galaxies in metals.
- NGC 3242 is a planetary nebula known as Ghost of Jupiter or Caldwell 59, discovered by William Herschel on February 7, 1785.
- NGC 3621: It is a barred spiral galaxy.
- NGC 5694 is one of the oldest globular clusters in the Milky Way; consequently, its stars show extremely low metallicity.
- ESO 510-G13: It is a deformed spiral galaxy.
- The Hydra Cluster: A cluster of galaxies is part of the Hydra-Centaur Supercluster.
Meteor Showers
According to the star shower log of the Adam Mickiewicz University (Poland), in the region comprising the constellation of Hydra, there are at least 17 meteor showers. The most notable are the following:
- Nu Hydrids: Occurs on March 19. This is the most important of all.
- Sigma Hydrids: Occurs from December 3 to 15, and peak observation occurs on December 12.
Interesting Facts
- Hydra is the largest and longest constellation of all. However, it has no first-magnitude stars, a very faint constellation.
- Hydra appears in several cultures of the southern hemisphere of the earth, such as the Inca culture or in the tribes of the Aborigines of Australia, almost always associated with the figure of a snake due to its elongated shape.
Conclusions
- Hydra is a constellation located primarily in the southern hemisphere; its name comes from the mythological creature of the Greek culture "Hydra," consisting of a snake-shaped sea monster.
- Hydra is the largest constellation in the sky. However, its stars are very faint, and therefore it is not so easy to locate with the naked eye.
- The best month to see the Hydra constellation is in April, between the latitudes of 54° N and 83° S.
- The easiest way to locate the constellation Hydra is by drawing an imaginary straight line from the constellation Leo to the constellation Centaurus; in the middle of the two, you will find the constellation Hydra.
- The brightest star in the constellation Hydra is Alfard (Alphard α Hya / α Hydrae / 30 Hya), with an apparent magnitude of +1.99.
- The constellation Hydra's most notable deep sky body is M83 (NGC 5236), better known as the Southern Grinder, one of the largest and brightest spiral galaxies in the Southern Hemisphere.
- The strongest meteor shower on Hydra is the "Nu Hydrids."