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M101 OT2015-1

M101 OT2015-1 is a science 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 M101 OT2015-1 rather than just read about it. In short: M101 OT2015-1 (also known as PSN J14021678+5426205, iPTF13afz and AT 2015dl) is a contact binary that merged into a single star, in a process known as a luminous red nova (LRN). M101 OT2015-1 is an optical transient located in the Pinwheel Galaxy (M101).

M101 OT2015-1 — main illustration
M101 OT2015-1 — illustration

Key takeaways

  • M101 OT2015-1 belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect M101 OT2015-1 to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of M101 OT2015-1 from memory before moving on to harder problems.

Reference excerpt

M101 OT2015-1 (also known as PSN J14021678+5426205, iPTF13afz and AT 2015dl) is a contact binary that merged into a single star, in a process known as a luminous red nova (LRN). M101 OT2015-1 is an optical transient located in the Pinwheel Galaxy (M101). Luminous red novae are representatives of the sparsely populated class of exploding variables which have been known since 1988, when such a star (M31-RV) appeared in the galaxy M31.

Discovery

M101 OT2015-1 was discovered on February 10, 2015 by Dumitru Ciprian Vîntdevară from Planetarium and Astronomical Observatory of the Museum Vasile Pârvan in Bârlad, Romania. The transient is located in the outer reaches of a spiral arm of M101, at 489″ W and 324″ N of the measured position of the galaxy nucleus. The transient was discovered with a Newtonian telescope 0,2 m + CCD camera ATIK 320E (on unfiltered) + EQ6 mount. On February 13, 2015, the New Zealand astronomer Stu Parker, using a telescope located in Spain, confirmed that a new object was visible in the M101 galaxy. The new object was initially reported as a possible supernova, with the designation PSN J14021678+5426205. Later it was shown that the new star was not a supernova, and for a while its nature remained uncertain. One month after the discovery, on March 11, 2015, an Astronomer's Telegram was published where the new star was described as a luminous red nova, confirmed spectroscopically. The final confirmation came a year later, on 2016 January 28, from observations carried out in several astronomic observatories in Russia.

Observations

Other information Although the nature of the object is still debated, its resemblance with other transients from the same LRN family points towards a possible binary origin. The unusual location of the progenitor star in the Hertzsprung gap supports the hypothesis that the most massive component had expanded beyond its roche lobe, initiating the common envelope phase. The outbursts detected for M101-OT2015-1 suggest that this CE was ejected on dynamical timescales, likely leaving a surviving close binary pair. Further observations at infrared wavelengths will help to show the exact nature of the M101 OT2015-1 system.

References

Illustrations

M101 OT2015-1 illustration
M101 OT2015-1: Astronomical Observatory of the Museum Vasile Pârvan in Bârlad, România
Astronomical Observatory of the Museum Vasile Pârvan in Bârlad, România
M101 OT2015-1: Spectrum of the LRN in M101 obtained with the BTA telescope and the SCORPIO camera on February 24, 2015 near the maximum of the second outburst.[3]
Spectrum of the LRN in M101 obtained with the BTA telescope and the SCORPIO camera on February 24, 2015 near the maximum of the second outburst.[3]
M101 OT2015-1: A red band light curve for M101 OT2015-1, adapted from Blagorodnova et al. (2017).[4] The inset plot shows the time near the outburst with an expanded scale.
A red band light curve for M101 OT2015-1, adapted from Blagorodnova et al. (2017).[4] The inset plot shows the time near the outburst with an expanded scale.

Worked examples

Example 1 — a first encounter with M101 OT2015-1

Start with the simplest possible case. Write down what M101 OT2015-1 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 M101 OT2015-1 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 M101 OT2015-1 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 M101 OT2015-1

In research
M101 OT2015-1 appears in science 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 M101 OT2015-1 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
M101 OT2015-1 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Luminous red novae, Ursa Major, so understanding it makes those chapters shorter.
In everyday life
Look for M101 OT2015-1 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 M101 OT2015-1 in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what M101 OT2015-1 means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain M101 OT2015-1 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is M101 OT2015-1 in simple terms?

M101 OT2015-1 (also known as PSN J14021678+5426205, iPTF13afz and AT 2015dl) is a contact binary that merged into a single star, in a process known as a luminous red nova (LRN). M101 OT2015-1 is an optical transient located in the Pinwheel Galaxy (M101).

Why does M101 OT2015-1 matter?

Because it connects several science 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 M101 OT2015-1?

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 M101 OT2015-1.

Tags

  • Luminous red novae
  • Ursa Major

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