astronomy

UGC 9684

UGC 9684 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 UGC 9684 rather than just read about it. In short: UGC 9684 is a barred spiral galaxy with a ring structure in the Boötes constellation. It is located 250 million light-years from the Solar System and has an approximate diameter of 90,000 light-years.

Key takeaways

UGC 9684 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect UGC 9684 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of UGC 9684 from memory before moving on to harder problems.

Reference excerpt

UGC 9684 is a barred spiral galaxy with a ring structure in the Boötes constellation. It is located 250 million light-years from the Solar System and has an approximate diameter of 90,000 light-years. The luminosity class of UGC 9684 is I–II and it is classified as an active star-forming galaxy according to a study published in 2022, in which produces one solar mass of stars every few years, with levels of stellar formation.

Studying of star formation rate for UGC 9684 Scientists who studied UGC 9684, have longed to find out the star-formation rate for UGC 9684. To do this, they used a Fitting and Assessment of Synthetic Templates code. The scientists used further observations via ultraviolet, both optical and near-infrared and from the luminosity measurements from different databases from GALEX, SDSS and from the final release of the MASS extended source catalog by Jarrett et al. 2000, with all the data retrieved from NASA/IPAC Extragalactic Database. As for the star formation, they employed a decreasing function of (SFR ∝ e−t ) and also a delayed function (SFR ∝ t × e−t ) as well as the stellar population libraries written from Bruzual & Charlot and Convoy et al. Several metallicity estimates, published by Prieto et al. 2008, Kelly & Kirshner from 2012, whom the majority agreed, it is slightly above solar oxygen abundance 12+ log(O/H) ≈ 9.0 which corresponds to ~2 Z⊙. Scientists therefore found that the star-formation rate of UGC 9684 is 0.25–0.39 M☉ yr−1. Apart from that, they found the total stellar mass for the galaxy is M⋆ = (2.0–3.5)×1010 M☉ which is a current specific rate sSFR ≈ 0.01 Gyr−1. This is higher compared to literature but compatible to large number of recent events in UGC 9684.

Supernovae Three supernovae and one astronomical transient have been discovered in UGC 9684, making it one of the most active supernova-producing galaxies.

SN 2006ed (Type II, mag. 19.0) was discovered on September 18, 2006, via unfiltered CCD images, by N. Joubert, D. R. Madison, R. Mostardi, H. Khandrika and W. Li from University of California, Berkeley on behalf of Lick Observatory Supernova Search program (LOSS). It was located 1".8 east and 7".2 south of the nucleus. SN 2012ib (Type Ib/c, mag. 16.0) was discovered on December 20, 2012, by amateur astronomer, V. Shumkov from Sternberg Astronomical Institute (SAI), on four 60-sec unfiltered images from the MASTER-Amur robotic telescope via a 0.40-m f/2.5 reflector. The supernova was located at 48".7 east and 0".4 south of the nucleus. AT 2017cgh (type unknown, mag. 17.74) was discovered on March 15, 2017, by Pan-STARRS1 Science consortium. It was located 0".0 east and 0".0 north of the nucleus. This astronomical transient was never officially classified as a supernova. SN 2020pni (Type II, mag. 19.8044) was discovered on July 16, 2020, by a team of astronomers on behalf of the ALeRCE broker via r-ZTF filters which was taken by a Palomar 1.2m Oachin telescope. It was located 5".7 west and 5".0 south of the nucleus. Its progenitor, a massive star, was enriched in helium and nitrogen in relative abundances in mass fractions of 0.30–0.40 and 8.2×10−3, respectively. A first study shows 1 day after the discovery, there was a significant He II emission which had strong flash features. Another study shows during the 4 days after, there was an increase in velocity of hydrogen lines (from ~250 to ~1000 km/s) suggesting complex circumstellar medium (CSM). A presence of dense and confined CSM as well as its inhomogeneous structure, indicates a phrase of enhanced mass loss of the SN 2020pni progenitor a year before the explosion. As of 2023, the supernova has since faded from view.

References

Illustrations

Worked examples

Example 1 — a first encounter with UGC 9684

Start with the simplest possible case. Write down what UGC 9684 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 UGC 9684 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 UGC 9684 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 UGC 9684

In research: UGC 9684 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 UGC 9684 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: UGC 9684 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Barred spiral galaxies, Boötes, IRAS catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for UGC 9684 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 UGC 9684 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what UGC 9684 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 UGC 9684 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is UGC 9684 in simple terms?

Why does UGC 9684 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 UGC 9684?

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 UGC 9684.