Bumerangnebulosan

Bumerangnebulosan
Bumerangnebulosan
Observationsdata
TypProtoplanetarisk nebulosa
StjärnbildKentauren
Rektascension12t 44m 45s
Deklination-54° 31′ 11″[1]
Avstånd5000 ljusår
Skenbar storlek1,445x0,724 bågminuter
Upptäckt
Upptäcktsår1980
UpptäckareKeith Taylor och Mike Scarrott
Andra beteckningar
HBC 592, ESO 172-7, IRAS 12419-5414, WKK98 1328, GN 12.41.9, LEDA 3074547, LFO93 1241-54[1]
Se även: Nebulosor, Lista över nebulosor
Hubblefoto

Bumerangnebulosan är en protoplanetarisk nebulosa belägen cirka 5 000 ljusår från jorden i Kentaurens stjärnbild. Bumerangnebulosan fotograferades av Hubbleteleskopet år 1998.

Med hjälp av Swedish-ESO Submillimetre Telescope vid La Silla-observatoriet i Chile mätte forskare 1995 temperaturen i nebulosan till 1 K (motsvarar −272,15 °C),[2] vilket gör nebulosan till den naturligt kallaste plats i universum som människan känner till hittills.

Referenser

Den här artikeln är helt eller delvis baserad på material från engelskspråkiga Wikipedia.
  1. ^ [a b] ”Basic data: NAME BOOMERANG NEBULA -- Interstellar matter”. SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Boomerang+nebula&submit=SIMBAD+search. Läst 2 september 2014. 
  2. ^ Sahai, Raghvendra; Nyman, Lars-Åke (1997). ”The Boomerang Nebula: The Coolest Region of the Universe?”. Astrophysical Journal 487 (2): sid. L155–L159. doi:10.1086/310897. 

Media som används på denna webbplats

Boomerang nebula.jpg

The Boomerang Nebula is a young planetary nebula and the coldest object found in the Universe so far. The NASA/ESA Hubble Space Telescope image is yet another example of how Hubble's sharp eye reveals surprising details in celestial objects.

This NASA/ESA Hubble Space Telescope image shows a young planetary nebula known (rather curiously) as the Boomerang Nebula. It is in the constellation of Centaurus, 5000 light-years from Earth. Planetary nebulae form around a bright, central star when it expels gas in the last stages of its life.

The Boomerang Nebula is one of the Universe's peculiar places. In 1995, using the 15-metre Swedish ESO Submillimetre Telescope in Chile, astronomers Sahai and Nyman revealed that it is the coldest place in the Universe found so far. With a temperature of -272C, it is only 1 degree warmer than absolute zero (the lowest limit for all temperatures). Even the -270C background glow from the Big Bang is warmer than this nebula. It is the only object found so far that has a temperature lower than the background radiation.

Keith Taylor and Mike Scarrott called it the Boomerang Nebula in 1980 after observing it with a large ground-based telescope in Australia. Unable to see the detail that only Hubble can reveal, the astronomers saw merely a slight asymmetry in the nebula's lobes suggesting a curved shape like a boomerang. The high-resolution Hubble images indicate that 'the Bow tie Nebula' would perhaps have been a better name.

The Hubble telescope took this image in 1998. It shows faint arcs and ghostly filaments embedded within the diffuse gas of the nebula's smooth 'bow tie' lobes. The diffuse bow-tie shape of this nebula makes it quite different from other observed planetary nebulae, which normally have lobes that look more like 'bubbles' blown in the gas. However, the Boomerang Nebula is so young that it may not have had time to develop these structures. Why planetary nebulae have so many different shapes is still a mystery.

The general bow-tie shape of the Boomerang appears to have been created by a very fierce 500 000 kilometre-per-hour wind blowing ultracold gas away from the dying central star. The star has been losing as much as one-thousandth of a solar mass of material per year for 1500 years. This is 10-100 times more than in other similar objects. The rapid expansion of the nebula has enabled it to become the coldest known region in the Universe.

The image was exposed for 1000 seconds through a green-yellow filter. The light in the image comes from starlight from the central star reflected by dust particles.
Boomerang HST big.jpg
Image of Boomerang nebula taken by Hubble Space Telescope