astronomy

LBQS 1009−0252

LBQS 1009−0252 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 LBQS 1009−0252 rather than just read about it. In short: LBQS 1009−0252 also Q1009−0252, is a gravitationally-lensed quasar located in the constellation of Sextans. It has a redshift of (z) 2.73 and it was first discovered by J.

Key takeaways

LBQS 1009−0252 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect LBQS 1009−0252 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of LBQS 1009−0252 from memory before moving on to harder problems.

Reference excerpt

LBQS 1009−0252 also Q1009−0252, is a gravitationally-lensed quasar located in the constellation of Sextans. It has a redshift of (z) 2.73 and it was first discovered by J. Surdej in February 1994 and later described a close-separation quasar pair with magnitudes of 18.2 and 21.2 by a team of astronomers led by P.C. Hewitt, the same year.

Description LBQS 1009−0252 consists of two bright quasars labelled A and B, having a separation gap of 1.53 ± 0.01 arcseconds. When imaged, they are separated into two components and lensed by an elliptical galaxy located at a redshift of (z) 0.871, confirmed by Very Large Telescope observations who found it closer to the fundamental plane redshift measurement calculated by C.S. Kochanek. A third quasar labelled C, is found at (z) 1.627 although it is fainter and possibly not relating to the pair. Observations determined the host galaxy of C is mainly responsible for the dominant cosmic shear contribution based on modelling of a isothermal ellipsoid although external shearing is contributed based on an isothermal sphere model by Claeskens with an orientation in the position angle of 11 ± 6 degrees. Ground-based observations and by Hubble Space Telescope have showed LBQS 1009−0252 has time-delays. Based on results, the time delay is found approximately 120.8 h−165 with the A component shown as the leading component based on estimation of the lens galaxy's redshift. Multicolor photometric light curves also showed both the A and B components of the quasars, do display some variations with the B component brightening up and the A component becoming slightly dimmer. This suggests a switch in the blue part of the spectrum in one of the quasars. Several absorption line systems have been identified in both A and B components of the quasars. When investigated, astronomers found these absorption lines are found rich in magnesium and iron oxides with redshifts of (z) 0.869 and (z) 1.627. Further evidence also pointed out the magnesium absorption system is extended by 40 h50−1 kiloparsecs, coinciding with the third quasar which in turn further extends outwards from it by 45 h50−1 kiloparsecs. More emission lines at (z) 2.739 and 2.740 are also discovered.

References

External links LBQS 1009−0252 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with LBQS 1009−0252

Start with the simplest possible case. Write down what LBQS 1009−0252 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 LBQS 1009−0252 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 LBQS 1009−0252 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 LBQS 1009−0252

In research: LBQS 1009−0252 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 LBQS 1009−0252 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: LBQS 1009−0252 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1994, Gravitationally lensed quasars, Quasars, so understanding it makes those chapters shorter.
In everyday life: Look for LBQS 1009−0252 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 LBQS 1009−0252 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what LBQS 1009−0252 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 LBQS 1009−0252 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is LBQS 1009−0252 in simple terms?

LBQS 1009−0252 also Q1009−0252, is a gravitationally-lensed quasar located in the constellation of Sextans. It has a redshift of (z) 2.73 and it was first discovered by J.

Why does LBQS 1009−0252 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 LBQS 1009−0252?

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 LBQS 1009−0252.