Constellation of Volans
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Volans
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Volans constellation lies in the southern sky. It is one of the smallest constellations. It represents the flying fish. Volans is the 76th constellation in size, occupying an area of 141 square degrees. It is located in the second quadrant of the southern sky (SQ2) and can be seen at latitudes between +15° and -90°. The neighboring constellations are Carina, Chamaeleon, Dorado, Mensa and Pictor.
[http://www.constellation-guide.com/constellation-list/volans-constellation/]
Volans, under its original name Piscis Volans, shown leaping against the side of the ship Argo on Chart XX of the Uranographia of Johann Bode (1801).
One of the 12 new constellations introduced at the end of the 16th century by the Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman. Volans represents a real type of fish found in tropical waters that can leap out of the water and glide through the air on wings. Sometimes the fish landed on the decks of ships and were used for food. In the sky the flying fish is imagined being chased by the predatory Dorado, as happens in reality.
The constellation was first depicted in 1598 on a globe by the Dutchman Petrus Plancius under the name Vliegendenvis. Bayer in 1603 called it Piscis Volans, the Latin title by which it became generally known until the mid 19th century. In 1844 the English astronomer John Herschel proposed shortening it to just Volans. Francis Baily adopted this suggestion in his British Association Catalogue of 1845, and it has been known as Volans ever since.
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Volans
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[http://www.koobecaf.hol.es/constellation-volans.html]
The six brightest stars in Volans are:
Beta Volantis is the brightest star in Volans constellation. It has an apparent magnitude of 3.77 and is 107.5 light years distant from the Sun. It is an orange giant with the stellar classification K1III. It has 1.62 solar masses and is 41 times more luminous than the Sun.
Gamma Volantis is a binary star in Volans, located about 142 light years from the Sun. The system is composed of the primary component, Gamma-2 Volantis, an orange giant with the stellar classification K0III, and Gamma-1 Volantis, a yellow-white main sequence star belonging to the stellar class F2V. Gamma-2 Volantis has an apparent magnitude of 3.78 and Gamma-1 has a visual magnitude of 5.68. The two stars are separated by 14.1 seconds of arc in the sky.
Zeta Volantis is another binary star in Volans. It has an apparent magnitude of 3.93 and is approximately 134 light years distant. The system consists of an orange giant belonging to the spectral class K0III and a 10th magnitude companion. The stars are separated by 16.7 arc seconds.
Delta Volantis is a yellow-white bright giant star with the stellar classification F6II. It has an apparent magnitude of 3.97 and is approximately 660 light years distant from the Sun.
Alpha Volantis is an Am star (metallic line star), which means that it is A-type chemically peculiar star with a strong spectrum and variable absorption lines of metals. It has the stellar classification of kA3hA5mA5 V. The star has an apparent magnitude of 4.00 and is approximately 125 light years distant from Earth. It is believed to be about 427 million years old.
Epsilon Volantis is a triple star system about 642 light years away in Volans constellation. It has an apparent magnitude of 4.35. The primary component in the system is a blue-white subgiant with the stellar classification of B6IV. It is a spectroscopic binary star with an orbital period of 14.17 days. The binary system has a companion with a visual magnitude of 8.1 located 6.05 arc seconds away.
[http://www.constellation-guide.com/constellation-list/volans-constellation/]
Deep-sky objects in Volans include the galaxy NGC 2442, whose distorted shape is likely the result of an ancient collision with another galaxy:
NGC 2442: Galaxy in Volans
Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish, (Piscis) Volans. Located about 50 million light-years away, the galaxy’s two spiral arms extending from a pronounced central bar give it a hook-shaped appearance. This deep color image also shows the arms’ obscuring dust lanes, young blue star clusters and reddish star forming regions surrounding a core of yellowish light from an older population of stars. But the star forming regions seem more concentrated along the drawn-out (right side) spiral arm. The distorted structure is likely the result of an ancient close encounter with the smaller galaxy seen near the top left of this field of view. The two interacting galaxies are separated by about 150,000 light-years at the estimated distance of NGC 2442.
[http://apod.nasa.gov/apod/ap090228.html]
NGC 2397 is another galaxy in Volans, which hosts a supernova:
Exploding star in NGC 2397
The latest image from the NASA/ESA Hubble Space Telescope reveals a sharp view of the spiral galaxy NGC 2397. This image also shows a rare Hubble view of the late stages of a supernova- SN 2006bc, discovered in March 2006.
Located nearly 60 million light-years away from Earth, the galaxy NGC 2397 is typical of most spirals, with mostly older, yellow and red stars in its central portion, while star formation continues in the outer, bluer spiral arms. The brightest of these young, blue stars can be seen individually in this high resolution view from the Hubble’s Advanced Camera for Surveys (ACS).
One atypical feature of this Hubble image is the view of supernova SN 2006bc taken when its brightness was on the decrease. Astronomers from Queen’s University Belfast in Northern Ireland, led by Professor of Astronomy Stephen J. Smartt, requested the image as part of a long project studying the massive exploding stars- supernovae. Exactly which types of star will explode and the lowest mass of star that can produce a supernova are not known.
When a supernova is discovered in a nearby galaxy the group begins a painstaking search of earlier Hubble images of the same galaxy to locate the star that later exploded; often one of hundreds of millions of stars in the galaxy. This is a little like sifting through days of CCTV footage to find one frame showing a suspect. If the astronomers find a star at the location of the later explosion, they may work out the mass and type of star from its brightness and colour. Only six such stars have been identified before they exploded and the Queen’s team have discovered the nature of five of them.
In their latest work on Hubble images, to be presented at the UK National Astronomy Meeting 2008 in Belfast, the Queen’s team reveals the results of their ten-year search for these elusive supernova precursor stars. It appears that stars with masses as low as seven times the mass of the Sun can explode as supernovae. The team have not found any very massive stars that exploded, suggesting that the most massive stars may collapse to form black holes either without producing a supernova or by producing one that is too faint to observe. This intriguing possibility will be discussed at the meeting.
The images were obtained on 14 October 2006 with Hubble’s Advanced Camera for Surveys (ACS) through three different colour filters (blue, green and near-infrared).
[https://www.spacetelescope.org/news/heic0808/]
AM 0644-741 is a ring galaxy, located in Volans:
Ring Galaxy AM 0644-741 from Hubble
How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. That galaxy, AM 0644-741, is known as a ring galaxy and was caused by an immense galaxy collision. When galaxies collide, they pass through each other- their individual stars rarely come into contact. The ring-like shape is the result of the gravitational disruption caused by an entire small intruder galaxy passing through a large one. When this happens, interstellar gas and dust become condensed, causing a wave of star formation to move out from the impact point like a ripple across the surface of a pond. The intruder galaxy is just outside of the frame taken by the Hubble Space Telescope. This featured image was taken to commemorate the anniversary of Hubble’s launch in 1990. Ring galaxy AM 0644-741 lies about 300 million light years away.
[http://apod.nasa.gov/apod/ap150419.html]
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