Posted on by Evan Gough

Hubble Gets its Best Look At the First Quasar

3C 273 is the uninspiring name given to the very first quasar to be linked with a visual object. Prior to that, quasars were known only by their radio emissions. The Hubble recently took a new, better look at the quasar, seen in this image. Image Credit: NASA, ESA, and STScI

The term quasar comes from quasi-stellar objects, a name that reflected our uncertainty about their nature. The first quasars were discovered solely because of their radio emissions, with no corresponding visual objects. This is surprising since quasars blaze with the light of trillions of stars.

In recent observations, the Hubble examined a historical quasar named 3C 273, the first quasar to be linked with a visual object.

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Posted on by David Dickinson

Using Quasars as a New Standard Candle to Define Distance

Quasar
This artist’s impression shows how the distant quasar P172+18 and its radio jets may have looked. To date (early 2021), this is the most distant quasar with radio jets ever found and it was studied with the help of ESO’s Very Large Telescope. It is so distant that light from it has travelled for about 13 billion years to reach us: we see it as it was when the Universe was only about 780 million years old.

A new study shows a way to use quasars to gauge distance in the early Universe.

The simple question of ‘how far?’ gets at the heart of the history of modern astronomy. Looking out across our galactic backyard into the primordial Universe, different yardsticks—often referred to as ‘standard candles’ —are used to gauge various distances, from near to far.

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