astronomy

S Ori 70

S Ori 70 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 S Ori 70 rather than just read about it. In short: S Ori 70 or S Ori J053810.1-023626 is a mid-T type astronomical object in the foreground of the σ Orionis cluster, which is approximately 1,150 light-years from Earth. It was discovered on November 24, 2002 by M.

Key takeaways

S Ori 70 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect S Ori 70 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of S Ori 70 from memory before moving on to harder problems.

Reference excerpt

S Ori 70 or S Ori J053810.1-023626 is a mid-T type astronomical object in the foreground of the σ Orionis cluster, which is approximately 1,150 light-years from Earth. It was discovered on November 24, 2002 by M. R. Zapatero-Osorio and E. L. Martin's team at the Roque de los Muchachos Observatory. It has yet to be determined if it is a field brown dwarf or a 3-million-year-old rogue planet that is part of a cluster. Near-infrared spectroscopy images taken three years after its discovery led to the first motion measurements for the object. Its behavior is significantly different from what may be expected; it was further described as either a low-gravity atmosphere or an atmosphere with metallicity. The object's small proper motion suggests that it is further away than expected if it were a single field T dwarf.

Discovery The σ Orionis open cluster has been the focus of Osorio's team observations due to the age of the cluster (approximately 3 to 8 million years). The cluster also has low extinction, its distance is convenient, and it is observed to be rich and dense. Using the 4.2-meter (170-inch) William Herschel Telescope in a pencil-beam deep mini-survey measuring 55 square minutes of arc at a sensitivity of 21 magnitudes in the J and H Bands allowed the team to find S Ori 70. The raw data collected was reduced to the Image Reduction and Analysis Facility (IRAF), a standard technique used with near-infrared images; after subtracting the sky background and dark current, an extracted object spectrum was derived. It was the faintest and coolest member found in the cluster and was named S Ori 70.

Argument of the initial study Adam J. Burgasser examined the claims of Osorio's T-type brown dwarf discovery and its spectroscopically verified low-mass. A comparison of the J band spectrum between S Ori 70 and other field objects was done. The J band spectrum revealed a distinct triangular-shaped spectral morphology which was previously explained by Zapatero-Osorio and Martín was due to the surface's low gravity. In order to see if similar discrepancies occurred in the T dwarf's behavior, Burgasser's team compared data from the claims of Osorio to that of standard COND models. Identical wavelength scales interpolated through both empirical and model spectra were Gaussian smoothed; this showed that best-fit spectral models can yield skewed gravities for late-type field T dwarfs which resulted in the underestimation of age and mass. Burgasser concluded that S Ori 70 is not a member of the Sigma Ori cluster but is rather a foreground field brown dwarf. Further study of the object suggest that the low gravity was not from the field T dwarf but rather a nearby background star. As of 2009 no direct scientific data have dispelled nor confirmed either conclusion. It could be the first "free floating" non-stellar planet discovered with a mass of 3 MJ, but needs confirmation.

See also List of exoplanet firsts S Ori 52

References

Illustrations

Worked examples

Example 1 — a first encounter with S Ori 70

Start with the simplest possible case. Write down what S Ori 70 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 S Ori 70 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 S Ori 70 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 S Ori 70

In research: S Ori 70 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 S Ori 70 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: S Ori 70 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Brown dwarfs, Exoplanets discovered in 2002, Orion (constellation), so understanding it makes those chapters shorter.
In everyday life: Look for S Ori 70 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 S Ori 70 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what S Ori 70 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 S Ori 70 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is S Ori 70 in simple terms?

Why does S Ori 70 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 S Ori 70?

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 S Ori 70.