astronomy

PKS 1302−102

PKS 1302−102 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 PKS 1302−102 rather than just read about it. In short: PKS 1302−102 is a quasar in the Virgo constellation, located at a distance of approximately 1.1 Gpc (around 3.5 billion light-years). It has an apparent magnitude of about 14.9 mag in the V band with a redshift of 0.2784.

Key takeaways

PKS 1302−102 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PKS 1302−102 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 1302−102 from memory before moving on to harder problems.

Reference excerpt

PKS 1302−102 is a quasar in the Virgo constellation, located at a distance of approximately 1.1 Gpc (around 3.5 billion light-years). It has an apparent magnitude of about 14.9 mag in the V band with a redshift of 0.2784. The quasar is hosted by a bright elliptical galaxy, with two neighboring companions at distances of 3 kpc and 6 kpc. The light curve of PKS 1302−102 appears to be sinusoidal with an amplitude of 0.14 mag and a period of 1,884 ± 88 days, which suggests evidence of a supermassive black hole binary.

Possible black hole binary PKS 1302−102 was selected from the Catalina Real-Time Transient Survey as one of 20 quasars with apparent periodic variations in the light curve. Of these quasars, PKS 1302−102 appeared to be the best candidate in terms of sinusoidal behavior and other selection criteria, such as data coverage of more than 1.5 cycles in the measured period. One plausible interpretation of the apparent periodic behavior is the possibility of two supermassive black holes (SMBH) orbiting each other with a separation of approximately 0.1 pc in the final stages of a 3.3 billion year old galaxy merger. If this turns out to be the case, it would make PKS 1302−102 an important object of study to various areas of research, including gravitational wave studies and the unsolved final parsec problem in a merger of black holes. Other explanations, of lesser likelihood, to the observed sinusoidal periodicity include a hot spot on the inner part of the black hole's accretion disk and the possibility of a warped accretion disk which partially eclipses in the orbit around a single SMBH. However, it also remains possible that the periodic behavior in PKS 1302−102 is indeed just a random occurrence in the light curve of an ordinary quasar, as spurious nearly-periodic variations can occur over limited time periods as part of stochastic quasar variability. Further observations of the quasar could either promote true periodicity or rule out a binary interpretation, especially if the measured light curve randomly diverges from the sinusoidal model.

References

Further reading Supermassive black hole binary discovered (at Ars Technica) Black Holes Inch Ahead to Violent Cosmic Union (at The New York Times)

Worked examples

Example 1 — a first encounter with PKS 1302−102

Start with the simplest possible case. Write down what PKS 1302−102 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 PKS 1302−102 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 PKS 1302−102 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 PKS 1302−102

In research: PKS 1302−102 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 PKS 1302−102 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: PKS 1302−102 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Principal Galaxies Catalogue objects, Quasars, Supermassive black hole binaries, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 1302−102 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 PKS 1302−102 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 1302−102 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 PKS 1302−102 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 1302−102 in simple terms?

Why does PKS 1302−102 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 PKS 1302−102?

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 PKS 1302−102.