astronomy

Orbiting Astronomical Observatory 2

Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2 rather than just read about it. In short: The Orbiting Astronomical Observatory 2 (OAO-2, nicknamed Stargazer) was the first successful space telescope (first space telescope being OAO-1, which failed to operate once in orbit), launched on December 7, 1968. An Atlas-Centaur rocket launched it into a nearly circular 750-kilometre (470 mi) altitude Earth orbit.

Key takeaways

Orbiting Astronomical Observatory 2 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Orbiting Astronomical Observatory 2 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Orbiting Astronomical Observatory 2 from memory before moving on to harder problems.

Reference excerpt

The Orbiting Astronomical Observatory 2 (OAO-2, nicknamed Stargazer) was the first successful space telescope (first space telescope being OAO-1, which failed to operate once in orbit), launched on December 7, 1968. An Atlas-Centaur rocket launched it into a nearly circular 750-kilometre (470 mi) altitude Earth orbit. Data was collected in ultraviolet on many sources including comets, planets, and galaxies. It had two major instrument sets facing in opposite directions; the Smithsonian Astrophysical Observatory (SAO) and the Wisconsin Experiment Package (WEP). One discovery was large halos of hydrogen gas around comets, and it also observed Nova Serpentis, which was a nova discovered in 1970.

Celescope: Smithsonian Astrophysical Observatory

The Smithsonian Astrophysical Observatory, also called Celescope, had four 12-inch (30 cm) Schwarzschild telescopes that fed into Uvicons. The Uvicon was an ultra-violet light detector based on the Westinghouse Vidicon. Ultraviolet light was converted into electrons which were in turn converted to a voltage as those electrons hit the detection area of the tube. There has been a Uvicon in the collection of the Smithsonian Institution since 1973. Various filters, photocathodes, and electronics aided in collecting data in several ultraviolet light passbands. The detectors showed a gradual loss of sensitivity and the experiment was turned off in April 1970. By the time it finished about 10 percent of the sky was observed resulting in a catalog of 5,068 UV stars.

Wisconsin Experiment Package

The Wisconsin Experiment Package had seven different telescopes for ultraviolet observations. For example, there was a nebular photoelectric photometer fed by a 16-inch (41 cm) telescope with a six-position filter wheel that unfortunately failed a few weeks after launch. Construction was supervised by Arthur Code of the University of Wisconsin-Madison. WEP observed over 1200 targets in ultraviolet light before the mission ended in early 1973.

Discoveries In addition to the Celescope's catalog of UV stars, the WEP observed comet Tago-Sato-Kosaka and found it to be surrounded by a cloud of hydrogen, confirming that the comet was largely made up of water, and detected the 2175-angstrom bump, an increase in UV absorption at that wavelength that is still not fully explained.

Spacecraft bus The observatory was built in the shape of an octagonal prism. It measured about 10 by 7 ft (3.0 by 2.1 m) and weighed 4,400 lb (2,000 kg).

Illustrations

Worked examples

Example 1 — a first encounter with Orbiting Astronomical Observatory 2

Start with the simplest possible case. Write down what Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2

In research: Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2 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: Orbiting Astronomical Observatory 2 is common in secondary-school and first-year university syllabi. It links to neighbouring topics American spacecraft stubs, Astronomical observatory stubs, Orbiting Astronomical Observatory, so understanding it makes those chapters shorter.
In everyday life: Look for Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Orbiting Astronomical Observatory 2 in simple terms?

Why does Orbiting Astronomical Observatory 2 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 Orbiting Astronomical Observatory 2?

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 Orbiting Astronomical Observatory 2.