astronomy

WISE 1217+1626

WISE 1217+1626 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 WISE 1217+1626 rather than just read about it. In short: WISEPC J121756.91+162640.2 (designation abbreviated to WISE 1217+1626, or WISE J1217+1626) is a binary brown dwarf system of spectral classes T9 + Y0, located in constellation Coma Berenices at approximately 30.4 light-years from Earth. History of observations Discovery WISE 1217+1626 A was discovered in 2011 by J.

Key takeaways

WISE 1217+1626 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect WISE 1217+1626 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of WISE 1217+1626 from memory before moving on to harder problems.

Reference excerpt

WISEPC J121756.91+162640.2 (designation abbreviated to WISE 1217+1626, or WISE J1217+1626) is a binary brown dwarf system of spectral classes T9 + Y0, located in constellation Coma Berenices at approximately 30.4 light-years from Earth.

History of observations

Discovery WISE 1217+1626 A was discovered in 2011 by J. Davy Kirkpatrick et al. from data, collected by Wide-field Infrared Survey Explorer (WISE) Earth-orbiting satellite—NASA infrared-wavelength 40 cm (16 in) space telescope, which mission lasted from December 2009 to February 2011. In 2011 Kirkpatrick et al. published a paper in The Astrophysical Journal Supplement, where they presented discovery of 98 new found by WISE brown dwarf systems with components of spectral types M, L, T and Y, among which also was WISE 1217+1626.

Initial estimate of spectral type Initial estimate of WISE 1217+1626' spectral type (before discovery of its binarity) was T9 (the same as the component's A type estimate made after this discovery).

Discovery of component B WISE 1217+1626 B was discovered in 2012 by Liu et al. with laser guide star (LGS) adaptive optics (AO) system of the 10-m Keck II Telescope on Mauna Kea, Hawaii, using infrared camera NIRC2 (the observations were made on 2012 January 29 (UT)). On 2012 April 1 (UT) Liu et al. observed WISE J1217+1626AB using the near-IR camera NIRI on the Gemini-North 8.1-m telescope on Mauna Kea, Hawaii and the binary was marginally resolved. On 12 April 2012 (UT) they obtained resolved spectroscopy of WISE J1217+1626AB with the near-IR spectrograph NIRSPEC again on the Keck II Telescope. In 2012 Liu et al. published a paper in The Astrophysical Journal where they presented results of observations with Keck II LGS-AO of three brown dwarf binary systems, binarity of one of which was known before, and binarity of the other two, including WISE 1217+1626, was first presented in this paper.

Physical properties Using three models, Liu et al. calculated physical properties of WISE 1217+1626 components for ages of 1 and 5 billion years. Later, models corresponding to age of the system equal to 1 billion years, were found to be poorly fitting and were discarded. From Burrows et al. (2003) models and M(J):

From Lyon/COND models and M(J):

From Lyon/COND models and Lbol:

Both components have a thin cloud layers in atmosphere. Despite being cold enough to have a chloride and sulfide clouds in atmosphere, component B atmosphere is not as cloudy as expected, possibly because of the system been metal-poor.

See also WISE J0336−0143 – first Y + Y binary brown dwarf system discovered The other two brown dwarf binary systems, observed by Liu et al. with Keck II LGS-AO in 2012:

WISE 1711+3500 (T8 + T9.5, binarity was newly discovered) CFBDSIR 1458+10 (T9 + Y0, binarity was known before) Lists:

List of star systems within 30–35 light-years List of Y-dwarfs

Notes

References

Illustrations

Worked examples

Example 1 — a first encounter with WISE 1217+1626

Start with the simplest possible case. Write down what WISE 1217+1626 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 WISE 1217+1626 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 WISE 1217+1626 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 WISE 1217+1626

In research: WISE 1217+1626 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 WISE 1217+1626 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: WISE 1217+1626 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Binary stars, Brown dwarfs, Coma Berenices, so understanding it makes those chapters shorter.
In everyday life: Look for WISE 1217+1626 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 WISE 1217+1626 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what WISE 1217+1626 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 WISE 1217+1626 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is WISE 1217+1626 in simple terms?

Why does WISE 1217+1626 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 WISE 1217+1626?

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 WISE 1217+1626.