We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Quasar?

Michael Anissimov
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Quasars (QUASi-stellAR radar sources) are gigantic luminous bodies between 780 million and 13 billion light years away, and correspondingly old. They are thought to be active galactic nuclei containing a central supermassive black hole. The brightest quasars are 2 trillion times brighter than our sun, or about 100 Milky Way galaxies. Their light output is continuous but can fluctuate in intensity on timescales of years, months, weeks, days or even hours, suggesting that they are quite dense.

Even as recently as the 1980s, there was significant disagreement among astrophysicists as to what quasars really are. A scientific consensus emerged when some quasars were found to be surrounded by galaxies, originating the active galactic nucleus theory. It has been calculated that, to generate the amount of light that they do, quasars must be powered by supermassive black holes that swallow between 10 and 1000 solar masses per year. In the accretion disc of such a black hole, superheated gases are accelerated to close to the speed of light, releasing tremendous amounts of electromagnetic waves as large portions of the mass is converted directly to energy. In such discs, about 10% of matter is converted to energy, in contrast to only 0.7% of the mass being converted to energy in fusion reactions within typical stars.

Quasars are believed to emit relativistic jets from their rotational poles, like their smaller cousins the pulsars. In 1979 quasars were used to confirm Einstein's theory of relativity, by observations of gravitational lensing effects as the quasar light traveled to the Earth. While at first it was thought that all quasars are "radio-loud" prompting their label as radio sources, subsequent observations revealed that only a minority (about 10%) of quasars emit copious radio energy. "Radio-quiet" quasars are referred to as QSOs (quasi-stellar objects), and play an extremely important role in studies of the early universe and how stars and galaxies first formed.

Early structures such as quasars might be interpreted as the "birth pangs" of galaxies. In the early universe, gases were more evenly distributed, so a newly formed black hole would have ample opportunities to suck in surrounding matter. Our own supermassive black hole at the center of the Milky Way, for instance, contains about 3.7 million solar masses, even though it started with much less mass than this. It has been busy sucking up other stars for billions of years, but the most intense stellar consumption probably occurred during its early history. This explains why we don't see any quasars in the modern universe but they are easily observable in older regions.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Anissimov
By Michael Anissimov
Michael Anissimov is a dedicated WiseGeek contributor and brings his expertise in paleontology, physics, biology, astronomy, chemistry, and futurism to his articles. An avid blogger, Michael is deeply passionate about stem cell research, regenerative medicine, and life extension therapies. His professional experience includes work with the Methuselah Foundation, Singularity Institute for Artificial Intelligence, and Lifeboat Foundation, further showcasing his commitment to scientific advancement.
Discussion Comments
By anon328028 — On Apr 01, 2013

Quasars are simply feeding galaxies. They are a natural part of the self-balancing mechanism of the universe. If you understood em energy and the universal process, you would know why that which you call quasars are not observed closer to us. Do you even know why they appear so bright?

By anon269430 — On May 17, 2012

I thought once black holes "filled up" they became Quasars, shooting out some of the matter they consumed at both ends.

By wizup — On May 24, 2011

@gifted6tulip – I’m not certain what it is your asking but from what has been discovered, the other 90% appear radio quiet. Or their electromagnetic radiation emits at such a low level it is undetected.

The theory behind this is that they may be linked to smaller black holes or in areas of space where there is less matter to consume.

By gifted6tulip — On Apr 30, 2009

If only 10% of quasars are radiofrequency emitting objects in space, what is the frequency of electromagnetic radiation that the other 90% of quasars emit that is detected here on earth?

Quasar astrophysics is really a fussy science...right?? no one really knows or understands this area of electromagnetic radiation hitting the earth from outer space, do they?

Michael Anissimov
Michael Anissimov
Michael Anissimov is a dedicated WiseGeek contributor and brings his expertise in paleontology, physics, biology,...
Learn more
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.