astronomy

Markarian 231

Markarian 231 is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Markarian 231 rather than just read about it. In short: Markarian 231 (UGC 8058) is a Type-1 Seyfert galaxy that was discovered in 1969 as part of a search for galaxies with strong ultraviolet radiation. It is named after the Armenian astronomer Benjamin Markarian, who played an active role in identifying and cataloging a number of active galaxies during the 1960s.

Key takeaways

Markarian 231 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Markarian 231 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Markarian 231 from memory before moving on to harder problems.

Reference excerpt

Markarian 231 (UGC 8058) is a Type-1 Seyfert galaxy that was discovered in 1969 as part of a search for galaxies with strong ultraviolet radiation. It is named after the Armenian astronomer Benjamin Markarian, who played an active role in identifying and cataloging a number of active galaxies during the 1960s. Markarian 231 contains the nearest known quasar and is located about 581 million light years away from Earth, in the constellation of Ursa Major.

Characteristics Markarian 231 is undergoing an energetic starburst. A nuclear ring at the center has an active rate of star formation of greater than 100 solar masses per year. It is one of the most ultraluminous infrared galaxies, with power derived from an accreting black hole in the center forming the closest known quasar. X-ray data shows the energy released from the black hole produces ultra-fast outflows with a velocity of −20,000 km s−1. The galaxy contains a curved radio jet interacting with the interstellar medium. Its position angle switches to −172° when reaching a projected distance of 25 pc. The Very Long Baseline Array found a triple radio source in Markarian 231. A 2015 study suggested the central black hole of 150 million solar masses has a black hole companion of 4 million solar masses, and that they orbit each other every 1.2 years. However, that model has been contested as unfeasible in 2016. Submillimetre astronomy has found evidence of molecular oxygen (O2), the first time molecular oxygen has been detected outside of the Milky Way galaxy. The Herschel Space Observatory showed water vapor in the galaxy's emission.

Illustrations

Worked examples

Example 1 — a first encounter with Markarian 231

Start with the simplest possible case. Write down what Markarian 231 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Markarian 231 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Markarian 231 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Markarian 231

In research: Markarian 231 appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Markarian 231 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Markarian 231 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Luminous infrared galaxies, Markarian galaxies, Principal Galaxies Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for Markarian 231 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Markarian 231” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Markarian 231 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Markarian 231 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Markarian 231 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Markarian 231 in simple terms?

Why does Markarian 231 matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Markarian 231?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Markarian 231.