astronomy

High Resolution Coronal Imager

High Resolution Coronal Imager 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 High Resolution Coronal Imager rather than just read about it. In short: The High Resolution Coronal Imager (Hi-C) is a sub-orbital telescope designed to take high-resolution images of the Sun's corona. As of 2020 it has been launched three times, but only the first and the third launches, on July 11, 2012, and May 29, 2018, resulted in a successful mission.

Key takeaways

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

Reference excerpt

The High Resolution Coronal Imager (Hi-C) is a sub-orbital telescope designed to take high-resolution images of the Sun's corona. As of 2020 it has been launched three times, but only the first and the third launches, on July 11, 2012, and May 29, 2018, resulted in a successful mission. It was launched aboard a Black Brant IX sounding rocket from White Sands Missile Range, New Mexico. The images taken were the highest resolution photos ever of the Sun's corona.

Telescope description The telescope weighs 464 pounds (210 kg), and is 10 feet (3.0 m) long. The mirrors are approximately 9.5 inches (24 cm) across. Its optics were designed at the Marshall Space Flight Center in Huntsville, Alabama with assistance from the Smithsonian Astrophysical Observatory and L-3Com/Tinsley Laboratories of Richmond, California. Dr. Jonathan Cirtain, from MSFC said: "These mirrors were to be the finest pieces of glass ever fabricated for solar astrophysics."

Imaging system The imaging system was designed by Apogee Imaging Systems with a resolution of 0.1 arcsec/pixel (14 times higher resolution than the Solar Dynamics Observatory). It was based on a customized version of the E2V CCD203 from Lockheed Martin, which is a very large 4 channel back illuminated 4,000 × 4,000 pixel charge-coupled device (CCD).

Missions

The first flight lasted for 10 minutes, reached an altitude of 283 kilometres (176 mi) and the telescope captured 165 images of a large active region. It imaged the Sun in ultraviolet light at 19.3 nm wavelength. The total cost of the mission was $5 million. On the second flight, in 2018, five and a half minutes (329 seconds) of pictures were taken of an area on the sun 4.4 arcminutes square (the sun's disk being about 30 arcminutes in diameter). Seventy eight images were taken at intervals of 4.4 seconds, with a two-second exposure time, at the extreme ultraviolet wavelength of 17.2 nanometres which is dominated by Fe IX emission (emission from iron in the +8 ionization state) indicating temperatures around 800 000 Kelvin. The instrument was able to resolve strands of plasma as narrow as about 200 kilometres wide.

Findings The first mission revealed never-before-seen "magnetic braids" of plasma roiling in the Sun's outer layers. It was the first time scientists were able to directly observe magnetic reconnection in braids, which may be the primary sources of heating in the active solar corona.

References

External links The Sun Revealed: Photos of the Million-degree Solar Corona, Space.com HI-C Sounding Rocket Mission Has Finest Mirrors Ever Made, NASA Archived 2012-07-13 at the Wayback Machine

Illustrations

Worked examples

Example 1 — a first encounter with High Resolution Coronal Imager

Start with the simplest possible case. Write down what High Resolution Coronal Imager 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 High Resolution Coronal Imager 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 High Resolution Coronal Imager 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 High Resolution Coronal Imager

In research: High Resolution Coronal Imager 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 High Resolution Coronal Imager 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: High Resolution Coronal Imager is common in secondary-school and first-year university syllabi. It links to neighbouring topics Solar space observatories, Space probes launched in 2012, Spacecraft which reentered in 2012, so understanding it makes those chapters shorter.
In everyday life: Look for High Resolution Coronal Imager 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 High Resolution Coronal Imager in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what High Resolution Coronal Imager 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 High Resolution Coronal Imager out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is High Resolution Coronal Imager in simple terms?

Why does High Resolution Coronal Imager 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 High Resolution Coronal Imager?

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 High Resolution Coronal Imager.