astronomy

PG 1612+261

PG 1612+261 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 1612+261 rather than just read about it. In short: PG 1612+261 known alternatively as TON 256 (abbreviation of Tonantzintla 256), is a Seyfert 1 galaxy located in the constellation of Corona Borealis. It is located 1.6 billion light-years away from Earth and was first discovered as a blue quasi-stellar galaxy in 1965.

Key takeaways

PG 1612+261 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 1612+261 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PG 1612+261 from memory before moving on to harder problems.

Reference excerpt

PG 1612+261 known alternatively as TON 256 (abbreviation of Tonantzintla 256), is a Seyfert 1 galaxy located in the constellation of Corona Borealis. It is located 1.6 billion light-years away from Earth and was first discovered as a blue quasi-stellar galaxy in 1965.

Description PG 1612+261 is a radio-quiet quasar with a redshift of (z) 0.131. It has a supermassive black hole mass of (2.3±0.6)×108 M☉ and a star formation rate of 1.30±0.03 M☉ yr–1. Its host galaxy is undisturbed based on H band imaging, with a bright central nucleus. Further evidence also showed it has either a normal or slightly reddened appearance. The spectrum of PG 1612+261 shows evidence of a helium broad emission feature. The source of the object is described having a steep radio spectrum between 5 and 8.5 GHz frequencies. It is also known to show radio outflows but no traces of broadline region wind. The radio structure of PG 1612+261 can be described as a triple structure that is being aligned in all directions with a compact faint source having a flux density of 0.17 mJy. There is also presence of diffused radio emission with an extension of 3 kiloparsecs. When revealed by a 8.4 GHz mapping by Very Large Array (VLA), the nuclear component is fully resolved into a double source with a one-sided jet found heading towards southwest. Radio imaging by Very Long Baseline Array (VLBA) at 1.4 GHz found it is found elongated by east to west direction while a 1.6 GHz radio image shows there are two components instead, with the western component having a spectral index of α 1.6 4.9 {\displaystyle \alpha _{1.6}^{4.9}} = −0.28±0.03. An emission narrow-line region is found surrounding PG 1612+261. Based on studies, the region is found dominated by large scale rotation motion. There is a doubly ionized oxygen line profile located close to the nucleus of PG 1612+261 with a line width of 424±24 km s–1. The radial velocity offset of the line is estimated to be −220±20 km s–1.

References

External links PG 1612+261 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PG 1612+261

Start with the simplest possible case. Write down what PG 1612+261 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 1612+261 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 1612+261 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 1612+261

In research: PG 1612+261 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 1612+261 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 1612+261 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Corona Borealis, IRAS catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for PG 1612+261 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 1612+261 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PG 1612+261 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 1612+261 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PG 1612+261 in simple terms?

Why does PG 1612+261 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 1612+261?

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 1612+261.