Emission nebula | |
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Observation data: J2000 epoch | |
Right ascension | 08h 56m 28.1s [1] |
Declination | −43° 05′ 58″ [1] |
Distance | 8200 ± 700 ly (2500 ± 200 [2] pc) |
Apparent magnitude (V) | 11.21 [1] |
Constellation | Vela (constellation) |
Designations | Gum 19, IRAS 08546-4254, VdBH 25 [1] |
RCW 34 (Gum 19) - H II region and the emission nebula located in the constellation Vela. It is located approximately 22,000 light years from Earth. Named after Australian astronomer Colin Stanley Gum. [3]
The nebula RCW 34 is relatively dark. However, when observed using infrared wavelengths, two different areas are visible - one half of the nebula is bright,and the other is dark. The bright side is the hydrogen illuminated by a nearby blue supergiant star, and dark is the place where new stars surround the central star on the other side.
The source of energy that stimulates the nebula RCW 34 to shine is a huge, extremely hot star V391 Velorum with a surface temperature of up to 30,000 °C. Because it is a variable star, it evokes violent phenomena, including discards of matter shells, affecting the composition and light emission of the RCW 34 nebula. Stars of the type V391 Velorum do not burn long enough to explode as supernovae. It can be expected that the explosion of the central star will completely change the RCW 34 nebula.
Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was the southern foundation of the larger constellation of Argo Navis until it was divided into three pieces, the other two being Puppis, and Vela.
A nebula is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral, or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the "Pillars of Creation" in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter and eventually become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects.
Vela is a constellation in the southern sky, which contains the Vela Supercluster. Its name is Latin for the sails of a ship, and it was originally part of a larger constellation, the ship Argo Navis, which was later divided into three parts, the others being Carina and Puppis. With an apparent magnitude of 1.8, its brightest star is the hot blue multiple star Gamma Velorum, one component of which is the closest and brightest Wolf-Rayet star in the sky. Delta and Kappa Velorum, together with Epsilon and Iota Carinae, form the asterism known as the False Cross. 1.95-magnitude Delta is actually a triple or quintuple star system.
The North America Nebula is an emission nebula in the constellation Cygnus, close to Deneb. It is named because its shape resembles North America.
Centaurus A is a galaxy in the constellation of Centaurus. It was discovered in 1826 by Scottish astronomer James Dunlop from his home in Parramatta, in New South Wales, Australia. There is considerable debate in the literature regarding the galaxy's fundamental properties such as its Hubble type and distance. NGC 5128 is one of the closest radio galaxies to Earth, so its active galactic nucleus has been extensively studied by professional astronomers. The galaxy is also the fifth-brightest in the sky, making it an ideal amateur astronomy target. It is only visible from the southern hemisphere and low northern latitudes.
The Carina Nebula or Eta Carinae Nebula is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky Way galaxy. The nebula is approximately 8,500 light-years (2,600 pc) from Earth.
The Lagoon Nebula is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region.
The California Nebula is an emission nebula located in the constellation Perseus. Its name comes from its resemblance to the outline of the US State of California in long exposure photographs. It is almost 2.5° long on the sky and, because of its very low surface brightness, it is extremely difficult to observe visually. It can be observed with a Hα filter or Hβ filter in a rich-field telescope under dark skies. It lies at a distance of about 1,000 light years from Earth. Its fluorescence is due to excitation of the Hβ line in the nebula by the nearby prodigiously energetic O7 star, Xi Persei.
V382 Velorum, also known as Nova Velorum 1999, was a bright nova which occurred in 1999 in the southern constellation Vela. V382 Velorum reached a brightness of 2.6 magnitude, making it easily visible to the naked eye. It was discovered by Peter Williams of Heathcote, New South Wales, Australia at 09:30 UT on 22 May 1999. Later that same day it was discovered independently at 10:49 UT by Alan C. Gilmore at Mount John University Observatory in New Zealand.
The Gum Nebula is an emission nebula that extends across 36° in the southern constellations Vela and Puppis. It lies approximately 450 parsecs from the Earth. Hard to distinguish, it was widely believed to be the greatly expanded remains of a supernova that took place about a million years ago. More recent research suggests it may be an evolved H II region. It contains the 11,000-year-old Vela Supernova Remnant, along with the Vela Pulsar.
HH 46/47 is a complex of Herbig–Haro objects, located around 450 parsecs away in a Bok globule near the Gum nebula. Jets of partially ionized gas emerging from a young star produce visible shocks upon impact with the ambient medium. Discovered in 1977, it is one of the most studied HH objects and the first jet to be associated with young stars was found in HH 46/47. Four emission nebulae, HH 46, HH 47A, HH 47C and HH 47D and a jet, HH 47B, have been identified in the complex. It also contains a mostly unipolar molecular outflow, and two large bow shocks on opposite sides of the source star. The overall size of the complex is about 3 parsecs.
Sh2-155 is a diffuse nebula in the constellation Cepheus, within a larger nebula complex containing emission, reflection, and dark nebulosity. It is widely known as the Cave Nebula, though that name was applied earlier to Ced 201, a different nebula in Cepheus. Sh2-155 is an ionized H II region with ongoing star formation activity, at an estimated distance of 725 parsecs from Earth.
The Gum catalog is an astronomical catalog of 84 emission nebulae in the southern sky. It was made by the Australian astronomer Colin Stanley Gum (1924-1960) at Mount Stromlo Observatory using wide field photography. Gum published his findings in 1955 in a study entitled A study of diffuse southern H-alpha nebulae which presented a catalog of 84 nebulae or nebular complexes. Similar catalogs include the Sharpless catalog and the RCW catalog, and many of the Gum objects are repeated in these other catalogs. However, the RCW and Gum catalogs were mainly of the southern hemisphere
RCW 120 is an emission nebula and H II region in the southern Milky Way and located some 4,300 light-years from Earth.
RCW 38 is an HII region containing a massive star cluster located approximately 5,500 light years away from Earth in the direction of the constellation Vela. The stars were very recently formed, and are still enshrouded within the dark cloud in which they were born. The star cluster is surrounded by clouds of brightly glowing gas and is composed of several short-lived massive stars, hundreds of young stars, and many protostars.
RCW 49, also known as NGC 3247, is a H II region nebula located 13,700 light years away. Other designations for the RCW 49 region include NGC 3247 and G29 and it is commonly known as the Whirling Dervish Nebula. It is a dusty stellar nursery that contains more than 2,200 stars and is about 300-400 light years across. RCW 49 is recognized as among the brightest and most massive HII regions.
RCW 88 is an emission nebula in the southern constellation of Circinus that first appeared in the 1960 astronomical catalogue by Rodgers, Campbell & Whiteoak (RCW) of Hα-emission regions within the southern Milky Way. Earlier observers, like James Wray in 1966, misclassified this as a likely 12.0v magnitude planetary nebula, but later spectroscopic investigations revealed this as a diffuse nebulae. RCW 88 was then to be identified by the infrared satellite IRAS as an HII region.
RCW 79 is an emission nebula in the constellation Centaurus.
RCW 36 is an emission nebula containing an open cluster in the constellation Vela. This H II region is part of a larger-scale star-forming complex known as the Vela Molecular Ridge (VMR), a collection of molecular clouds in the Milky Way that contain multiple sites of ongoing star-formation activity. The VMR is made up of several distinct clouds, and RCW 36 is embedded in the VMR Cloud C.
Vela Molecular Ridge is a molecular cloud complex in the constellations Vela and Puppis. Radio 12CO observations of the region showed the ridge to be composed of several clouds, each with masses 100,000–1,000,000 M☉. This cloud complex lies on the sky in the direction of the Gum Nebula (foreground) and the Carina–Sagittarius Spiral Arm (background). The most important clouds in the region are identified by the letters A, B, C and D, and in fact belong to two different complexes: the clouds A, C and D are located at an average distance of about 700-1000 parsecs and are related to the OB association Vela R2, while cloud B is located at a greater distance, up to 2000 parsecs away, and is physically connected to the extended Vela OB1 association.