astronomy

Tim Hawarden

Tim Hawarden 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 Tim Hawarden rather than just read about it. In short: Timothy George Hawarden (24 December 1943 – 10 November 2009) was a South African astrophysicist known for his pioneering work on passive cooling techniques for space telescopes for which he won NASA's Exceptional Technology Achievement Medal. Biography Hawarden was born in Mossel Bay, Cape Province, South Africa.

Key takeaways

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

Reference excerpt

Timothy George Hawarden (24 December 1943 – 10 November 2009) was a South African astrophysicist known for his pioneering work on passive cooling techniques for space telescopes for which he won NASA's Exceptional Technology Achievement Medal.

Biography Hawarden was born in Mossel Bay, Cape Province, South Africa. He graduated from the University of Natal in 1966 with a BSc in Physics and Applied Mathematics, and then graduated from the University of Cape Town with an MSc in Astronomy 1970 and then a PhD in 1975 on old open clusters. While undertaking his PhD he worked as an optical astronomer at the Royal Observatory, Cape of Good Hope and then from 1972 as the Deputy Head of the Photometry Department at the South African Astronomical Observatory in Cape Town. In 1975 he worked as the Deputy Astronomer-in-Charge of the UK Schmidt Telescope at the Siding Spring Observatory in New South Wales, Australia. In 1978 he moved to work at the Royal Observatory in Edinburgh, Scotland, from which he was based for the rest of his career. In 1981 he began working on the United Kingdom Infrared Telescope in Hawaii. In 1987 he moved to Hawaii and led the telescope's ambitious upgrades programme throughout the 1990s. He returned to Edinburgh in 2001 and became the UK Astronomy Technology Centre Project Scientist developing extremely large telescopes (ELT) before retiring in 2006 to care for his wife Frances. He remained active in the field of astronomy until his sudden death in Edinburgh in 2009.

Passive cooling of space telescopes Hawarden was involved in the development of the Infrared Space Observatory as the Co-Investigator for the infrared camera (ISOCAM) but he considered the cryogenic cooling system "horrendously complicated". The dependency of infrared space telescopes on cryogenic cooling limited the telescope's lifespan as well as adding significant weight. In the early 1980s Hawarden began developing the idea of using passive cooling for infrared space telescopes through a combination of radiators, sunshields, and by locating the telescope further from Earth. Having a telescope orbit the Sun–Earth L2 Lagrange point enables the sunshield to shelter the telescope from the radiant heat of the Sun, the Earth, and the Moon. A passively cooled telescope is significantly lighter and permits much larger optics and instruments. In 1989 Hawarden proposed such a telescope, the Passively Cooled Orbiting Infrared Observatory Telescope (POIROT) to the European Space Agency but the design was rejected. In 1991 Hawarden and Harley Thronson proposed a similar design to NASA for the Edison project but the proposal was also rejected. The ideas continued to face resistance though some passive cooling was incorporated into the design of the 0.85 m (2.8 ft) diameter Spitzer Space Telescope launched in 2003. The ideas were later adopted in full for the 6.5 m (21 ft) diameter James Webb Space Telescope launched in 2021. In 2010 Hawarden was posthumously awarded the NASA Exceptional Technology Achievement Medal for his work on passive cooling techniques, the award citing "the breakthrough concepts that made possible the James Webb Space Telescope and its successors". The award was accepted on behalf of Hawarden's widow Frances by the Nobel-laureate physicist John C. Mather.

References

Worked examples

Example 1 — a first encounter with Tim Hawarden

Start with the simplest possible case. Write down what Tim Hawarden 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 Tim Hawarden 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 Tim Hawarden 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 Tim Hawarden

In research: Tim Hawarden 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 Tim Hawarden 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: Tim Hawarden is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1943 births, 2009 deaths, 20th-century astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for Tim Hawarden 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 Tim Hawarden in 20 minutes

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

Frequently asked questions

What is Tim Hawarden in simple terms?

Why does Tim Hawarden 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 Tim Hawarden?

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 Tim Hawarden.