Vela
[http://astropixels.com/constellations/charts/Vel.html]
[https://www.iau.org/static/archives/images/screen/vel.jpg]
Vela constellation lies in the southern hemisphere. Its name means ‘the sails’ in Latin. Vela was once part of the much larger constellation, Argo Navis, which represented the Argonauts’ ship, but was eventually divided into three smaller constellations: Vela (the sails), Carina (the keel) and Puppis (the stern). Vela is the 32nd constellation in size, occupying an area of 500 square degrees. It is located in the second quadrant of the southern hemisphere (SQ2) and can be seen at latitudes between +30° and -90°. The neighboring constellations are Antlia, Carina, Centaurus, Puppis and Pyxis.
[http://www.constellation-guide.com/constellation-list/vela-constellation/]
Traditionally, the sail of Argo has been shown furled around a cross-spar on the main mast, as in this early illustration from the Uranographia of Johann Bayer in 1603, and not open and billowing as imagined in some popular representations.
Vela is one of the three sections into which the French astronomer Nicolas Louis de Lacaille divided the oversized Greek constellation of Argo Navis, the Argonauts’ ship, in his southern star catalogue of 1756. In that catalogue he gave it the French name Voilure du Navire. Vela represents the ship’s sails; the other sections are Carina, the Keel, and Puppis, the Stern.
Not only did Lacaille dismantle Argo Navis, he also relabelled its stars, since he was dissatisfied with Bayer’s arrangement. But he still used only one set of Greek letters for all three parts of Argo. As a result, Vela possesses no stars labelled Alpha or Beta, since these letters were allocated to the two brightest stars in Carina.
[http://www.ianridpath.com/startales/vela.htm]
Constellations of Antlia, Pyxis and Vela
[http://www.davidmalin.com/fujii/source/Ant.html]
[http://www.peoplesguidetothecosmos.com/constellations/vela.htm]
Gamma Velorum is the brightest star in Vela constellation. It has an apparent magnitude of 1.7. It is in fact a multiple star system composed of at least six stars, approximately 336 light years distant from Earth.
The primary component in the system, Gamma-2 Velorum or Gamma Velorum A, is a spectroscopic binary star composed of a blue supergiant with the stellar classification of O7.5 and a massive Wolf-Rayet star, an evolved, extremely hot, massive star which is rapidly losing mass as a result of a very strong stellar wind. The Wolf-Rayet star is one of the nearest supernova candidates to Earth and will likely end its life in a Type Ic supernova explosion. The two stars orbit each other with a period of 78.5 days and are separated by 1 astronomical unit.
The nearest companion to the binary star, Gamma-1 Velorum or Gamma Velorum B, is a blue-white class B subgiant star. Other components of the system are Gamma Velorum C, a white star with a visual magnitude of 8.5, and another binary star composed of Gamma Velorum D and Gamma Velorum E. Gamma Velorum D is another white, class A star with an apparent magnitude of 9.4, and Gamma Velorum E is a 13th magnitude star.
The star system’s traditional name, ‘Suhail’, is derived from the Arabic ‘suhayl al-muħlif,’ which means ‘the glorious (star) of the oath.’
Delta Velorum is the second brightest star in the constellation. It has an apparent magnitude of 1.96 and is 80.6 light years distant from the Sun. It is located near the border with the constellation Carina. This is another multiple star system. It is composed of Delta Velorum A and Delta Velorum B, which have a wide orbit and a 142 year orbital period. Delta Velorum A has a visual magnitude of 1.97 and Delta Velorum B has a magnitude of 5.55. The primary component is itself a spectroscopic binary star with an orbital period of 45.15 days. It is the brightest eclipsing binary star system known. Both stars in the system have evolved away from the main sequence. Both are rapid spinners and believed to be about 400 million years old. Another binary system can be found at a separation of 69 arc seconds. It consists of an 11th magnitude and 13th magnitude stars separated by 6 seconds of arc. Delta Velorum is sometimes known as Koo She, which is Chinese for ‘bow and arrows.’
Lambda Velorum is the third brightest star in Vela. It has an apparent magnitude of 2.21 and is approximately 545 light years distant from Earth. It shares the traditional name Suhail with the brighter Gamma Velorum. In China, the star is known as Pinyin, which means ‘judge for estimating the age of animals.’ Lambda Velorum has the stellar classification of K4.5Ib-II, which means that it is an orange star halfway between the bright giant and supergiant stages. It is classified as an LC-type slow irregular variable star. It exhibits variations in brightness ranging from apparent magnitude 2.14 to 2.30. The star is about 8.5 times more massive than the Sun and 10,000 times more luminous. It is believed to be about 32 million years old. It has a radius 207 times solar.
[http://www.constellation-guide.com/constellation-list/vela-constellation/]
A stack of twelve HST epochs of the Luhman 16 binary brown dwarf. The A+B components are the yellow discs at the center of the image.
Luhman 16 (WISE 1049−5319, WISE J104915.57−531906.1) is a binary brown-dwarf system in the southern constellation Vela at a distance of approximately 6.5 light-years (2.0 parsecs) from the Sun. These are the closest-known brown dwarfs and the closest system found since the measurement of the proper motion of Barnard’s Star in 1916, and the third-closest-known system to the Sun (after the Alpha Centauri system and Barnard’s Star). The primary is of spectral type L7.5 and the secondary of type T0.5 ± 1. The masses of Luhman 16 A and B are 34 and 28 Jupiter masses, respectively, and their ages are estimated to be 600–800 million years. Luhman 16 A and B orbit each other at a distance of about 3.5 astronomical units with an orbital period of approximately 27 years.
[https://en.wikipedia.org/wiki/Luhman_16]
IRAS 08544-4431 (V390 Velorum) is an aging star with a dust disk surround it:
Sharpest view ever of dusty disc around aging star
The Very Large Telescope Interferometer at ESO’s Paranal Observatory in Chile has obtained the sharpest view ever of the dusty disc around an aging star. For the first time such features can be compared to those around young stars- and they look surprisingly similar. It is even possible that a disc appearing at the end of a star’s life might also create a second generation of planets.
As they approach the ends of their lives many stars develop stable discs of gas and dust around them. This material was ejected by stellar winds, whilst the star was passing through the red giant stage of its evolution. These discs resemble those that form planets around young stars. But up to now astronomers have not been able to compare the two types, formed at the beginning and the end of the stellar life cycle.
Although there are many discs associated with young stars that are sufficiently near to us to be studied in depth, there are no corresponding old stars with discs that are close enough for us to obtain detailed images.
But this has now changed. Thanks to the unprecedented sharpness of the images from the Very Large Telescope Interferometer, and a new imaging technique that can remove the central stars from the image to reveal what lies around them, a team of scientists could dissect all the building blocks of the IRAS 08544-4431 system for the first time.
Their target was the old double star IRAS 08544-4431, lying about 4000 light-years from Earth in the southern constellation of Vela (The Sails). This double star consists of a red giant star, which expelled the material in the surrounding dusty disc, and a less-evolved more normal star orbiting close to it.
The most prominent feature of the image is the clearly resolved ring. The inner edge of the dust ring, seen for the first time in these observations, corresponds very well with the expected start of the dusty disc: closer to the stars, the dust would evaporate in the fierce radiation from the stars.
The team finds that discs around old stars are indeed very similar to the planet-forming ones around young stars. Whether a second crop of planets can really form around these old stars is yet to be determined, but it is an intriguing possibility.
[http://www.eso.org/public/usa/news/eso1608/]
Artists’s impression of planet HD 85512 b
HD 85512 is a solitary K-type main-sequence star located approximately 36 light-years away in the constellation Vela. It is approximately one billion years older than the Sun. It is extremely chromospherically inactive, only slightly more active than Tau Ceti.
On August 19, 2011, a ≥3.6 Earth-mass planet was discovered using HARPS that is ‘just inside’ the habitable zone, along with the planets of 82 G. Eridani and HR 7722 c. The planet could be potentially cool enough to host liquid water if the planet exhibits more than 50% cloud coverage. HD 85512 b is currently the fifth best candidate for habitability according to the Habitable Exoplanets Catalog.
[https://en.wikipedia.org/wiki/HD_85512]
NGC 2547 is an open cluster in Vela:
Young stars in the open star cluster NGC 2547
This image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile, shows the bright open star cluster NGC 2547. Between the bright stars, far away in the background of the image, many remote galaxies can be seen, some with clearly spiral shapes.
[https://www.eso.org/public/images/eso1316a/]
NGC 3201 is a globular cluster in Vela:
The globular cluster NGC 3201
Color-composite image of the globular cluster NGC 3201, obtained with the WFI instrument on the ESO/MPG 2.2-m telescope at La Silla. Globular clusters are large aggregates of stars, that can contain up to millions of stars. They are among the oldest objects observed in the Universe and were presumably formed at about the same time as the Milky Way Galaxy, in the early phase after the Big Bang. This particular globular cluster is located about 16 000 light-years away towards the Southern Vela constellation.
[https://www.eso.org/public/images/ngc3201/]
The Vela supernova remnant is a supernova in the constellation Vela, whose light reached Earth about 11,000 years ago:
Vela Supernova Remnant
The plane of our Milky Way Galaxy runs through this complex and beautiful skyscape. At the northwestern edge of the constellation Vela (the Sails) the telescopic frame is over 10 degrees wide, centered on the brightest glowing filaments of the Vela Supernova Remnant, an expanding debris cloud from the death explosion of a massive star. Light from the supernova explosion that created the Vela remnant reached Earth about 11,000 years ago. In addition to the shocked filaments of glowing gas, the cosmic catastrophe also left behind an incredibly dense, rotating stellar core, the Vela Pulsar. Some 800 light-years distant, the Vela remnant is likely embedded in a larger and older supernova remnant, the Gum Nebula.
[http://apod.nasa.gov/apod/ap150101.html]
The Gum Nebula is a vast cloud of hydrogen gas, spanning across Vela constellation:
The Gum Nebula
Named for Australian astronomer Colin Stanley Gum (1924-1960), The Gum Nebula is so large and close it is actually hard to see. In fact, we are only about 450 light-years from the front edge and 1,500 light-years from the back edge of this cosmic cloud of glowing hydrogen gas. Covered in this 41 degree-wide mosaic of H-alpha images, the faint emission region is otherwise easy to lose against the background of Milky Way stars. The complex nebula is thought to be a supernova remnant over a million years old, sprawling across the southern constellations Vela and Puppis. This spectacular wide field view reveals the location of objects embedded in The Gum Nebula, including the Vela supernova remnant.
[http://apod.nasa.gov/apod/ap060519.html]
Nearby the Vela Supernova Remnant is NGC 2736, also known as the Pencil Nebula:
NGC 2736
Nearby the Vela Pulsar, and a small part of the Vela Supernova Remnant is NGC 2736, also known as the Pencil Nebula. The nebula’s linear appearance triggered its popular name. It resides about 815 light-years (250 parsecs) away from the Solar System. It is thought to be formed from part of the shock wave of the larger Vela Supernova Remnant. The Pencil Nebula is moving at roughly 644,000 kilometers per hour (400,000 miles per hour).
[https://en.wikipedia.org/wiki/NGC_2736]
On the border of the constellation with Antlia, lies the planetary nebula NGC 3132:
NGC 3132: The Eight Burst Nebula
It’s the dim star, not the bright one, near the center of NGC 3132 that created this odd but beautiful planetary nebula. Nicknamed the Eight-Burst Nebula and the Southern Ring Nebula, the glowing gas originated in the outer layers of a star like our Sun. In this representative color picture, the hot blue pool of light seen surrounding this binary system is energized by the hot surface of the faint star. Although photographed to explore unusual symmetries, it’s the asymmetries that help make this planetary nebula so intriguing. Neither the unusual shape of the surrounding cooler shell nor the structure and placements of the cool filamentary dust lanes running across NGC 3132 are well understood.
[http://apod.nasa.gov/apod/ap150607.html]
HH-47 is a Herbig-Haro Object; a young star around 1400 light-years from our Sun that is ejecting material at tremendous speed (up to a million kilometres per hour) into its surrounds. This material glows as it hits surrounding gas:
[https://en.wikipedia.org/wiki/HH_47]
HH-47 Star Jet
The star masked by a dust cloud at the left of the above photo is expelling an energetic beam of charged particles into interstellar space. This jet, moving from left to right, has burrowed through much interstellar material, and now expands out into the interstellar space. Although jet particles move at nearly three hundred kilometers per second, we still do not see any daily movement because of the enormous distances involved. In fact, the jet is trillions of kilometers long. This stellar jet occurs in a system called HH-47 which is located near the edge of the Gum Nebula.
[http://apod.nasa.gov/apod/ap951012.html]
Associated with the Vela Supernova Remnant, is the Vela Pulsar:
Vela Pulsar jet: New Chandra movie features neutron star action
This movie (previous picture) from NASA’s Chandra X-ray Observatory shows a fast moving jet of particles produced by a rapidly rotating neutron star, and may provide new insight into the nature of some of the densest matter in the universe.
The star of this movie is the Vela pulsar, a neutron star that was formed when a massive star collapsed. The Vela pulsar is about 1,000 light years from Earth, spans about 12 miles in diameter, and makes over 11 complete rotations every second, faster than a helicopter rotor. As the pulsar whips around, it spews out a jet of charged particles that race out along the pulsar's rotation axis at about 70% of the speed of light. In this still image from the movie, the location of the pulsar and the 0.7-light-year-long jet are labeled.
The Chandra data shown in the movie, containing 8 images obtained between June and September 2010, suggest that the pulsar may be slowly wobbling, or precessing, as it spins. The shape and the motion of the Vela jet look strikingly like a rotating helix, a shape that is naturally explained by precession, as shown in this animation. If the evidence for precession of the Vela pulsar is confirmed, it would be the first time that a jet from a neutron star has been found to be precessing in this way.
One possible cause of precession for a spinning neutron star is that it has become slightly distorted and is no longer a perfect sphere. This distortion might be caused by the combined action of the fast rotation and ‘glitches,’ sudden increases of the pulsar's rotational speed due to the interaction of the superfluid core of the neutron star with its crust.
Wide field Optical and X-ray
The supernova that formed the Vela pulsar exploded over 10,000 years ago. This optical image from the Anglo-Australian Observatory’s UK Schmidt telescope shows the enormous apparent size of the supernova remnant formed by the explosion. The full size of the remnant is about eight degrees across, or about 16 times the angular size of the moon. The square near the center shows the Chandra image with a larger field-of-view than used for the movie, with the Vela pulsar in the middle.
[http://chandra.harvard.edu/photo/2013/vela/index.html]
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