science

HE 0435−1223

HE 0435−1223 is a science 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 HE 0435−1223 rather than just read about it. In short: HE 0435−1223 is a quadruple-lensed quasar and rare Einstein Cross located in the constellation Eridanus at a distance of approximately 2.33 billion light years away from Earth. HE 0435−1223 was discovered in October 2008 by astronomer Patrick Foley during a study and search for gravitational quadruple lenses in deep sky objects.

Key takeaways

HE 0435−1223 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HE 0435−1223 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HE 0435−1223 from memory before moving on to harder problems.

Reference excerpt

HE 0435−1223 is a quadruple-lensed quasar and rare Einstein Cross located in the constellation Eridanus at a distance of approximately 2.33 billion light years away from Earth. HE 0435−1223 was discovered in October 2008 by astronomer Patrick Foley during a study and search for gravitational quadruple lenses in deep sky objects.

Physical properties The main physical characteristic of HE 0435−1223 is the fact that it is divided into four frames by the galaxy WSB2002 0435−1223 G. All images are spaced a maximum of 2.6 arcsecs apart, the brightest image named "A" has an apparent magnitude of 19 while the other three images ("B","C" and "D") have an apparent magnitude of 19.6. The quasar itself is estimated to have an apparent magnitude of 17.71. All these images are pale blue in color. According to measurements in the I band, the galaxy producing the lens would be a giant elliptical galaxy with a diameter of 12 kpc. In 2006, a research team studied HE 0435−1223 with the Hubble Space Telescope, they observed that the brightness of the four images varies in a particular way, if image A varies, image B will vary with a delay compared to image A. According to scientists, the object producing the lensing may not be a galaxy but a possible unorganized galactic structure which would produce several gravitational lenses that distort HE 0435−1223, and this would explain the delay between the magnitudes of each image.

Supermassive black hole In 2017, scientists studied the emission lines as well as the inert zone of the quasar using the MMT Observatory. By recombining the emissions from the different images, the team of scientists were able to carry out fairly precise measurements. By studying the microwaves emitted by HE 0435−1223, they were able to estimate the speed and temperature of the black hole's accretion disk. With this data, they were able to estimate the mass of the black hole which sits at the center of the quasar; for this process, they used the relationship between the measurements as well as the mass of the central black hole. Data from the variation of emission fluxes indicate that the central black hole of HE 0435−1223 would have a mass of approximately ~10 billion solar masses.

See also Gravitational lens List of quasars

External links HE 0435−1223 at SIMBAD

References

Illustrations

Worked examples

Example 1 — a first encounter with HE 0435−1223

Start with the simplest possible case. Write down what HE 0435−1223 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 HE 0435−1223 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 HE 0435−1223 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 HE 0435−1223

In research: HE 0435−1223 appears in science 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 HE 0435−1223 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: HE 0435−1223 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Eridanus (constellation), Quasars, so understanding it makes those chapters shorter.
In everyday life: Look for HE 0435−1223 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 HE 0435−1223 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HE 0435−1223 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 HE 0435−1223 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HE 0435−1223 in simple terms?

Why does HE 0435−1223 matter?

Because it connects several science 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 HE 0435−1223?

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 HE 0435−1223.