astronomy

PKS 0727−11

PKS 0727−11 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 0727−11 rather than just read about it. In short: PKS 0727−11 is a blazar located in southern constellation of Puppis. The redshift of the object has been determined as (z) 1.591, with it first being discovered during the Parkes survey conducted at the Parkes Observatory in 1966.

Key takeaways

PKS 0727−11 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 0727−11 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PKS 0727−11 from memory before moving on to harder problems.

Reference excerpt

PKS 0727−11 is a blazar located in southern constellation of Puppis. The redshift of the object has been determined as (z) 1.591, with it first being discovered during the Parkes survey conducted at the Parkes Observatory in 1966. The radio spectrum of the object is flat, classifying it a flat-spectrum radio quasar.

Description PKS 0727−11 has been found variable on the electromagnetic spectrum. It is noted for its variable flux density near 5 GHz and at the 10.6 GHz mark when it was observed between 1968 and 1969, with evidence of rapid variations at 2.3 GHz in 1971. It also had an amplitude outburst at 2 Jy, which subsequently peaked in 1975 at frequencies ranging from 10.6 to 2.7 GHz. A gamma-ray flare was detected from PKS 0727−11 on 21 September 2010 by Fermi Gamma-ray Space Telescope with its daily gamma-ray flux reaching levels of 1.4 ± 0.4 × 10−6 photons cm2, an increase of 3.5 in factor. Increased gamma-ray flux reached around 5.0 ± -0.8 × 10−7 photons cm−2 s−1 back in January 2009. The source of the quasar is mainly core-dominated with a jet shown, having either a 90° or a large bend. The quasar is classified as a polarization rotator. When observed in 1981 by Hugh Aller, it is found to display a systemic time change in polarization which began in middle of 1977. Although on average with a change rate of +106°, it did not occur in linear manner according to Aller. However it is noted to occur in a series of jumps in position angles, with observed large differences of +55° in April 1978, +70° in January 1979, +82° in June 1979 and +68° by September of 1980. Aller also noted the polarization degree of PKS 0727−11 at 4.8 and 8.0 GHz frequencies, appeared fluctuated at a time-scale on the order of half-year. A series of outbursts also occurred in PKS 0727−11 beginning late 1973, with a change of position angle of 90°. In February 2025, PKS 0727−11 is found to undergo a quasi-periodic oscillation with a period of 168 days. This is likely explained by non-ballistic helical motion in its jet, which in turn is driven by orbital motion of its binary supermassive black hole system. The mass for the primary black hole in PKS 0727−11 is estimated in the range between 3.66 × 108 and 5.79 × 109 M☉.

References

External links PKS 0727−11 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with PKS 0727−11

Start with the simplest possible case. Write down what PKS 0727−11 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 0727−11 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 0727−11 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 0727−11

In research: PKS 0727−11 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 0727−11 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 0727−11 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 1966, Blazars, so understanding it makes those chapters shorter.
In everyday life: Look for PKS 0727−11 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 0727−11 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PKS 0727−11 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 0727−11 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PKS 0727−11 in simple terms?

Why does PKS 0727−11 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 0727−11?

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 0727−11.