Matches in DBpedia 2014 for { <http://dbpedia.org/resource/Cassiopeia_A> ?p ?o. }
Showing items 1 to 60 of
60
with 100 items per page.
- Cassiopeia_A abstract "Cassiopeia A (Cas A) is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. It had a flux density of 2720±50 Jy at 1 GHz in 1980; its flux density at 1 GHz is decreasing at a rate of 0.97±0.04 percent per year. This decrease means that at frequencies below 1 GHz Cas A is now less intense than Cyg A. The supernova occurred approximately 11,000 light-years (3.4 kpc) away in the Milky Way. The expanding cloud of material left over from the supernova now appears approximately 10 light-years (3 pc) across from Earth's perspective (within the Milky Way Galaxy). Despite its radio brilliance, however, it is extremely faint optically, and is only visible on long-exposure photographs.It is believed that first light from the stellar explosion reached Earth approximately 300 years ago but there are no historical records of any sightings of the progenitor supernova, probably due to interstellar dust absorbing optical wavelength radiation before it reached Earth (although it is possible that it was recorded as a sixth magnitude star 3 Cassiopeiae by John Flamsteed on August 16, 1680). Possible explanations lean toward the idea that the source star was unusually massive and had previously ejected much of its outer layers. These outer layers would have cloaked the star and reabsorbed much of the light released as the inner star collapsed.Cas A is 3C461 in the Third Cambridge Catalogue of Radio Sources and G111.7-2.1 in the Green Catalog of Supernova Remnants. The expansion shell has a temperature of around 50 million degrees Fahrenheit (30 megakelvins), and is expanding at 4000−6000 km/s.Cas A is the strongest radio source in the sky beyond our solar system, and was among the first discrete sources to be found, in 1947. The optical component was first identified in 1950.In 2013, it was reported that phosphorus had been detected in Cassiopeia A, which confirmed that this element is produced in supernovae, with the Phosphorus-Iron ratio up to 100 times higher in material from the supernova remnant than in the Milky Way in general.".
- Cassiopeia_A thumbnail Cassiopeia_A_Spitzer_Crop.jpg?width=300.
- Cassiopeia_A wikiPageExternalLink 7814351.stm.
- Cassiopeia_A wikiPageID "1996903".
- Cassiopeia_A wikiPageRevisionID "600894889".
- Cassiopeia_A bV "Unknown".
- Cassiopeia_A caption "A false color image composited of data from three sources. Red is infrared data from the Spitzer Space Telescope, orange is visible data from the Hubble Space Telescope, and blue and green are data from the Chandra X-ray Observatory. The cyan dot just off-center is the remnant of the star's core.".
- Cassiopeia_A constellation Cassiopeia_(constellation).
- Cassiopeia_A dec "+58° 48′".
- Cassiopeia_A discovery "1947".
- Cassiopeia_A epoch "J2000".
- Cassiopeia_A gal "G111.7-2.1".
- Cassiopeia_A hasPhotoCollection Cassiopeia_A.
- Cassiopeia_A host Milky_Way.
- Cassiopeia_A magV "6".
- Cassiopeia_A name "Cassiopeia A".
- Cassiopeia_A notes "Strongest radio source beyond our solar system".
- Cassiopeia_A progenitor "Unknown".
- Cassiopeia_A progenitorType "Unknown".
- Cassiopeia_A ra "84206.0".
- Cassiopeia_A sizeV "5".
- Cassiopeia_A snrtype "Shell".
- Cassiopeia_A type Type_II_supernova.
- Cassiopeia_A subject Category:1947_in_science.
- Cassiopeia_A subject Category:3C_objects.
- Cassiopeia_A subject Category:Cassiopeia_(constellation).
- Cassiopeia_A subject Category:Milky_Way_Galaxy.
- Cassiopeia_A subject Category:Supernova_remnants.
- Cassiopeia_A type Abstraction100002137.
- Cassiopeia_A type Leftover113811184.
- Cassiopeia_A type Part113809207.
- Cassiopeia_A type Relation100031921.
- Cassiopeia_A type Remainder113810818.
- Cassiopeia_A type SupernovaRemnants.
- Cassiopeia_A comment "Cassiopeia A (Cas A) is a supernova remnant (SNR) in the constellation Cassiopeia and the brightest extrasolar radio source in the sky at frequencies above 1 GHz. It had a flux density of 2720±50 Jy at 1 GHz in 1980; its flux density at 1 GHz is decreasing at a rate of 0.97±0.04 percent per year. This decrease means that at frequencies below 1 GHz Cas A is now less intense than Cyg A. The supernova occurred approximately 11,000 light-years (3.4 kpc) away in the Milky Way.".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Cassiopeia A".
- Cassiopeia_A label "Кассиопея A".
- Cassiopeia_A label "ذات الكرسي أ".
- Cassiopeia_A label "カシオペヤ座A".
- Cassiopeia_A label "仙后座A".
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A sameAs カシオペヤ座A.
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A sameAs m.06csxm.
- Cassiopeia_A sameAs Q618273.
- Cassiopeia_A sameAs Q618273.
- Cassiopeia_A sameAs Cassiopeia_A.
- Cassiopeia_A wasDerivedFrom Cassiopeia_A?oldid=600894889.
- Cassiopeia_A depiction Cassiopeia_A_Spitzer_Crop.jpg.
- Cassiopeia_A isPrimaryTopicOf Cassiopeia_A.
