astronomy

PG 1216+069

PG 1216+069 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 PG 1216+069 rather than just read about it. In short: PG 1216+069 is a quasar and also a Seyfert 1 galaxy located in the constellation of Virgo. The redshift of the object is (z) 0.331 and it was first discovered by astronomers from the Bright Quasar Survey (BQS) in June 1983.

Key takeaways

PG 1216+069 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PG 1216+069 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PG 1216+069 from memory before moving on to harder problems.

Reference excerpt

PG 1216+069 is a quasar and also a Seyfert 1 galaxy located in the constellation of Virgo. The redshift of the object is (z) 0.331 and it was first discovered by astronomers from the Bright Quasar Survey (BQS) in June 1983. It has also been classified as a radio intermediate quasar (RIQ) in literature.

Description PG 1216+069 is radio-quiet. It is hosted by a large elliptical galaxy, based on Hubble Space Telescope (HST) imaging, which has an absolute magnitude of around -20.9. It is also surrounded by a halo structure. Two close companions are found to be located from the galaxy by 13.6 and 20.4 kiloparsecs respectively. A subdampened Lyman-alpha absorption line system was located towards the quasar. The radio structure of PG 1216+069 can be considered as compact. When imaged with the Very Long Baseline Array (VLBA), it has a compact radio core with a brightness temperature of >108 Kelvin, with its flux density peaking at around 1.04 mJy frequencies. Radio imaging made with Very Long Baseline Interferometry (VLBI) found the component radio spectrum is flat, with the spectral shape being described as inverted. A slightly extended structure is found based on radio mapping at 5 and 8.4 GHz frequencies. A supermassive black hole mass has been estimated for PG 1216+069, and is estimated to be 8.30 ± 0.12 M☉. There have also been detections of doubly ionized silicon absorption at high velocities towards the quasar, spread out evenly across two components that are separating from each other at 234 kilometers per second.

References

External links PG 1216+069 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PG 1216+069

Start with the simplest possible case. Write down what PG 1216+069 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 PG 1216+069 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 PG 1216+069 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 PG 1216+069

In research: PG 1216+069 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 PG 1216+069 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: PG 1216+069 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1983, Elliptical galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for PG 1216+069 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.

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How to study PG 1216+069 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PG 1216+069 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 PG 1216+069 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PG 1216+069 in simple terms?

Why does PG 1216+069 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 PG 1216+069?

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 PG 1216+069.