astronomy

SDSS J112155.27+104923.2

SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2 rather than just read about it. In short: SDSS J112155.27+104923.2 is an elliptical galaxy located in the constellation of Leo. The redshift of the galaxy is estimated to be (z) 0.240 and it was first discovered by astronomers in October 2007, from a sample of fossil groups in the Sloan Digital Sky Survey (SDSS).

Key takeaways

SDSS J112155.27+104923.2 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SDSS J112155.27+104923.2 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SDSS J112155.27+104923.2 from memory before moving on to harder problems.

Reference excerpt

SDSS J112155.27+104923.2 is an elliptical galaxy located in the constellation of Leo. The redshift of the galaxy is estimated to be (z) 0.240 and it was first discovered by astronomers in October 2007, from a sample of fossil groups in the Sloan Digital Sky Survey (SDSS).

Description SDSS J112155.27+104923.2 is an elliptical galaxy residing as the brightest cluster galaxy of the WHL J112155.3+104923 galaxy cluster with 23 confirmed galaxy member candidates. The R-band magnitude of the galaxy is 17.14 while the total stellar mass of the galaxy is 11.24 M☉. The absolute magnitude of the galaxy is -23.84 magnitude. It is also categorized as a fossil galaxy dominating the fossil group called FGS 12, with its total X-ray luminosity estimated to be 3.85 × 1043 erg/s while the velocity dispersion is 251 ± 21 kilometers per seconds. The effective surface brightness is 18.61 ± 0.34 magnitudes per square arcsecond while its effective radius is 11.1 ± 3.0 kiloparsec. The position angle of the galaxy is orientated at 100.9 ± 3.0°. The galaxy is found to contain an active galactic nucleus. Radio imaging made with Very Large Array at 1.4 GHz, finds the radio source is mainly point-like and elongated with the total radio extent being 11.0 arcseconds and has an root mean square noise of 57 ɥJy beam−1. The total radio flux density is estimated to be 4.8 mJy while the total radio luminosity is 23.90 W Hz−1. A study suggested the source is mainly elongated depicted as a single elliptical component with the radio core detected by Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) having a flux density of 4.19 mJy.

References

External links

SDSS J112155.27+104923.2 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Illustrations

Worked examples

Example 1 — a first encounter with SDSS J112155.27+104923.2

Start with the simplest possible case. Write down what SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2

In research: SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2 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: SDSS J112155.27+104923.2 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Active galaxies, Astronomical objects discovered in 2007, Elliptical galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SDSS J112155.27+104923.2 in simple terms?

Why does SDSS J112155.27+104923.2 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 SDSS J112155.27+104923.2?

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 SDSS J112155.27+104923.2.