astronomy

J2345−0449

J2345−0449 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 J2345−0449 rather than just read about it. In short: J2345−0449 or 2MASX J23453268−0449256, is a spiral galaxy located 947 million light-years away in the constellation of Aquarius. It contains an active galactic nucleus and is classified as a radio galaxy, containing relativistic jets that are projected out from its spiral host by ~1.6 Mpc, making these jets the largest and rarest known.

Key takeaways

J2345−0449 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect J2345−0449 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of J2345−0449 from memory before moving on to harder problems.

Reference excerpt

J2345−0449 or 2MASX J23453268−0449256, is a spiral galaxy located 947 million light-years away in the constellation of Aquarius. It contains an active galactic nucleus and is classified as a radio galaxy, containing relativistic jets that are projected out from its spiral host by ~1.6 Mpc, making these jets the largest and rarest known. It was discovered in 2014 by amateur astronomers, making it the third spiral DRAGN after ESO 0313-192 and Speca.

Physical Properties Mentioned as a megaparsec-scale object at redshift 0.0757, J2345−0449 is one of the largest and most massive spiral galaxies found in the local universe. It is also one of the largest radio sources discovered since the galaxy exhibits two sets of radio lobes found in near alignment and spanning a width of ~387.2 kpc (~452) and ~1.63 Mpc (~191). According to Very Large Array 6 cm imaging, the inner radio lobes are categorized either Fanaroff-Riley Class I or FR II morphology. A further study in 2025, showed these inner radio lobes extend right up to 387.2 kiloparsecs (Kpc). J2345−0449 contains a fast rotation speed of Vrot = 371/sin (i) = 429 ± 30 km s−1 that is r ≥ 10 kpc away from its galactic center. It has a mass of Mstellar = 4 × 1011 M☉ and a surrounding ring of molecular gas measured 24 kpc wide in diameter. The galaxy has a star formation rate with a surface density measured to be ΣSFR = 1.8 × 10−3 M☉ yr−1 kpc−2. However it has a low factor between 30 and 70 as expected according to the Kennicutt-Schmidt law.

Black hole mass The black hole mass estimation is challenging since J2345−0449 has no classic bulge structure. According to Bagchi, the black hole has a mass of 2.5 ± 0.5 × 108 M☉. Further observations shows it has a mass of 1.4× 109 M☉ when calculating the MBH–σ relation proposed by Gültekin. However, according to researchers obtaining the M–σ relation from McConnell & Ma, the actual mass of J2345−0449 is 5 × 109 M☉.

References

Illustrations

Worked examples

Example 1 — a first encounter with J2345−0449

Start with the simplest possible case. Write down what J2345−0449 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 J2345−0449 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 J2345−0449 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 J2345−0449

In research: J2345−0449 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 J2345−0449 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: J2345−0449 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aquarius (constellation), Astronomical objects discovered in 2014, Principal Galaxies Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for J2345−0449 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “J2345−0449” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study J2345−0449 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what J2345−0449 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 J2345−0449 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is J2345−0449 in simple terms?

Why does J2345−0449 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 J2345−0449?

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 J2345−0449.