B2 1420+32 is a changing-look blazar, study finds

An international team of astronomers has performed multi-wavelength photometric and spectroscopic observations of a blazar known as B2 1420+32. The observational campaign found that the object exhibits a large scale spectral ...

A blazar in the early Universe

The supersharp radio 'vision' of the National Science Foundation's Very Long Baseline Array (VLBA) has revealed previously unseen details in a jet of material ejected at three-quarters the speed of light from the core of ...

Variability of blazar 3C 273 examined by astronomers

Using data from space observatories and ground-based telescopes, astronomers have investigated variability of a blazar known as 3C 273. The new study, presented in a paper published July 6 on the arXiv pre-print server, sheds ...

Astronomers report most distant blazar ever observed

Although it may have a difficult designation to remember, PSO J030947.49+271757.31, the most distant blazar observed to date, reveals important details about ancient black holes and places tight constraints on theories of ...

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Blazar

A blazar (blazing quasi-stellar object) is a very compact quasar (quasi-stellar object) associated with a presumed supermassive black hole at the center of an active, giant elliptical galaxy. Blazars are among the most energetic phenomena in the universe and are an important topic in extragalactic astronomy.

Blazars are members of a larger group of active galaxies that host active galactic nuclei (AGN). A few rare objects may be "intermediate blazars" that appear to have a mixture of properties from both optically violent variable (OVV) quasars and BL Lac objects. The name "blazar" was originally coined in 1978 by astronomer Edward Spiegel to denote the combination of these two classes.

Blazars are AGN with a relativistic jet that is pointing in the general direction of the Earth. We observe "down" the jet, or nearly so, and this accounts for the rapid variability and compact features of both types of blazars. Many blazars have apparent superluminal features within the first few parsecs of their jets, probably due to relativistic shock fronts.

The generally accepted picture is that OVV quasars are intrinsically powerful radio galaxies while BL Lac objects are intrinsically weak radio galaxies. In both cases the host galaxies are giant ellipticals.

Alternative models, for example, gravitational microlensing, may account for a few observations of some blazars which are not consistent with the general properties.

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