RX J0852.0−4622 (also known as G266.2−1.2) is a

supernova remnant A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar mat ...

. The remnant is located in the southern sky in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Vela ("sail"), and sits (in projection) inside the much larger and older Vela Supernova Remnant. For this reason, RX J0852.0−4622 is often referred to as Vela Junior (Vela Jr.). There have been a minority of suggestions that the remnant may be a spurious identification of a complicated substructure within the larger and better studied Vela SNR, but most studies accept that G266.2−1.2 is a SNR in its own right. Indeed, its detection in the high energy Teraelectronvolt range by the

High Energy Stereoscopic System High Energy Stereoscopic System (H.E.S.S.) is a system of imaging atmospheric Cherenkov telescopes (IACTs) for the investigation of cosmic gamma rays in the photon energy range of 0.03 to 100 TeV. The acronym was chosen in honour of Vic ...

in 2005 is strong confirmation of such. It was found in 1998 with an analysis of data from the

ROSAT ROSAT (short for Röntgensatellit; in German X-rays are called Röntgenstrahlen, in honour of Wilhelm Röntgen) was a German Aerospace Center-led satellite X-ray telescope, with instruments built by West Germany, the United Kingdom and the Un ...

x-ray telescope. Published simultaneously with its discovery was a claimed detection by the

Compton Gamma Ray Observatory The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with photon energy, energies from 20 kElectronvolt#Properties, eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main tel ...

of a

gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

spectral line of ⁴⁴Ti which has a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

of 60 years and therefore seemed to indicate a young provenance for the supernova, perhaps the youngest one yet discovered. Later independent groups could not reproduce the detection, and so the consensus is that the identification of this line was likely spurious. Since the age and distance are correlated, a young, nearby supernova like this has inspired some detective work to identify evidence that such a supernova may have been observed and recorded by groups of people, and geochronologists have looked for evidence of a young supernova in tree ring and ice core data, but identification of claimed correlate signals have not been conclusively made. The latest analyses of the remnant indicate an age of at least 2400 years (and possibly much older), a distance of no less than 500 parsecs, and a radial size of at least 8 parsecs. The

central compact object A central compact object (CCO) is an x-ray source found near the center of a young, nearby supernova remnant (SNR). Given the observed x-ray flux and spectra observed from these objects, the almost certain conclusion is that CCOs are the remnant n ...

(CCO) was discovered in 2001. In the initial

Chandra Chandra (), also known as Soma (), is the Hindu god of the Moon, and is associated with the night, plants and vegetation. He is one of the Navagraha (nine planets of Hinduism) and Dikpala (guardians of the directions). Etymology and other ...

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

image and deeper images thereafter, no pulsations were detected from the compact remnant, which is believed to be the

neutron star A neutron star is the gravitationally collapsed Stellar core, core of a massive supergiant star. It results from the supernova explosion of a stellar evolution#Massive star, massive star—combined with gravitational collapse—that compresses ...

CXOU J085201.4-461753. A different

pulsar A pulsar (''pulsating star, on the model of quasar'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its Poles of astronomical bodies#Magnetic poles, magnetic poles. This radiation can be obse ...

was suggested as the remnant, but its kinematics do not conform as well to the observed kinematics of the remnant shell.

References

External links

* {{DEFAULTSORT:RX J0852.0-4622 Gum Nebula Supernova remnants Vela (constellation) ROSAT objects