astronomy

Oskar Backlund

Oskar Backlund 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 Oskar Backlund rather than just read about it. In short: Johan Oskar Backlund (28 April 1846 – 29 August 1916) was a Swedish-Russian astronomer. His name is sometimes given as Jöns Oskar Backlund, however even contemporary Swedish sources give "Johan".

Key takeaways

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

Reference excerpt

Johan Oskar Backlund (28 April 1846 – 29 August 1916) was a Swedish-Russian astronomer. His name is sometimes given as Jöns Oskar Backlund, however even contemporary Swedish sources give "Johan". In Russia, where he spent his entire career, he is known as Oskar Andreevich Baklund (Russian: Оскар Андреевич Баклунд). Russian sources sometimes give his dates of birth and death as 16 April 1846 and 16 August 1916, since Russia still used the Julian calendar at the time.

Life He was born in Länghem, in Västergötland, Sweden and graduated from Uppsala University in 1872. After getting his doctorate in 1875, he emigrated to Russia in 1876. He worked at Dorpat Observatory, in today's Tartu, Estonia, and then in 1879 worked at Pulkovo Observatory, becoming director of the observatory from 1895 until his death. He specialized in celestial mechanics, and notably worked on calculating the orbit of Comet Encke, taking into account the perturbations of various planets. He used observations of Comet Encke to try estimate the mass of Mercury. Russian sources sometimes referred to the comet as Comet Encke-Backlund. He also carried out geodesic studies in Spitzbergen from 1898 to 1900. He became a member of the Saint Petersburg Academy of Sciences in 1883, member of the Royal Swedish Academy of Sciences in 1897 and Fellow of the Royal Society in 1911. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1914.

Family He was married to Ulrika Catharina Widebeck. Their daughter Elsa Celsing became a well-known artist, and their son Helge Gotrik Backlund (3 September 1878–1958) was a geologist and explorer.

Honors Awards

Gold Medal of the Royal Astronomical Society (1909) Bruce Medal (1914) Named after him

The crater Backlund on the Moon Asteroid 856 Backlunda Backlundtoppen, a mountain in Olav V Land at Spitsbergen, Svalbard.

References

External links Bruce Medal page Archived 2020-11-27 at the Wayback Machine Awarding of Bruce Medal Awarding of RAS gold medal Backlund, Johan Oskar (Svenskt biografiskt handlexikon) in Project Runeberg (in Swedish) I:56 (Svenskt biografiskt handlexikon) in Project Runeberg (in Swedish) II:795 (Svenskt biografiskt handlexikon) in Project Runeberg (in Swedish) https://www.genealogy.math.ndsu.nodak.edu/id.php?id=234324

Obituaries AN 203 (1916) 235/236 (in German) MNRAS 77 (1916) 310 Obs 40 (1917) 128–131

Illustrations

Oskar Backlund: Oskar Backlund in 1900 — Oskar Backlund in 1900

Worked examples

Example 1 — a first encounter with Oskar Backlund

Start with the simplest possible case. Write down what Oskar Backlund 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 Oskar Backlund 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 Oskar Backlund 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 Oskar Backlund

In research: Oskar Backlund 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 Oskar Backlund 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: Oskar Backlund is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1846 births, 1916 deaths, 19th-century Swedish astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for Oskar Backlund 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 Oskar Backlund in 20 minutes

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

Frequently asked questions

What is Oskar Backlund in simple terms?

Johan Oskar Backlund (28 April 1846 – 29 August 1916) was a Swedish-Russian astronomer. His name is sometimes given as Jöns Oskar Backlund, however even contemporary Swedish sources give "Johan".

Why does Oskar Backlund 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 Oskar Backlund?

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 Oskar Backlund.