astronomy

HIP 11915 b

HIP 11915 b 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 HIP 11915 b rather than just read about it. In short: HIP 11915 b is a candidate exoplanet orbiting the solar twin star HIP 11915 about 175 light-years (54 parsecs) from Earth in the constellation Cetus. It is notable as its orbit and mass are similar to that of Jupiter (essentially, a "Jupiter analog"), suggesting that its system may be similar to that of the Solar System.

Key takeaways

HIP 11915 b belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HIP 11915 b to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HIP 11915 b from memory before moving on to harder problems.

Reference excerpt

HIP 11915 b is a candidate exoplanet orbiting the solar twin star HIP 11915 about 175 light-years (54 parsecs) from Earth in the constellation Cetus. It is notable as its orbit and mass are similar to that of Jupiter (essentially, a "Jupiter analog"), suggesting that its system may be similar to that of the Solar System. It orbits its star at a distance of approximately 4.8 AU.

Discovery The exoplanet was found by using the radial velocity method, where periodic Doppler shifts of spectral lines of the host star suggest an orbiting object. While the radial velocity variations are most likely caused by an orbiting planet, the discovery paper could not completely rule out the possibility that the variations are caused by the star's activity cycle, so HIP 11915 b technically remains a planet candidate.

Physical characteristics

Mass and temperature HIP 11915 b is a jovian planet, an exoplanet with a mass close to that of the planet Jupiter. It has a minimum mass of 0.99 MJ (315 M🜨). Based on models, it is expected to have a temperature of around 118 K (−155 °C; −247 °F). This is nearly the same as the planet Jupiter.

Host star

The host star, HIP 11915, is a G-type star that is just about the same mass of the Sun (a solar twin). It has a temperature of 5760 K, nearly the same as the Sun, which has a temperature of 5778 K. The star's age is estimated to be about 4.16 billion years old, about 440 million years younger than the Sun, which is 4.6 billion years old. The radius of the star has not been directly known, but given the same mass as the Sun, HIP 11915 likely has a radius of around 1.01 R☉, making it the same size as the Sun. The star's apparent magnitude, or how bright it appears from Earth's perspective, is 8.58. Therefore, HIP 11915 is too dim to be seen with the naked eye, but can be seen with good binoculars.

Orbit HIP 11915 b orbits its host star with an orbital period of 10 years and an orbital radius of about 4.8 times that of Earth's (nearly the same as Jupiter, which has an orbital distance of around 5.2 AU). Its eccentricity is 0.1, slightly higher than Jupiter's, meaning it has an orbit slightly more eccentric. This would not have any effect on any residing planets near the star, though.

Significance in astronomy The discovery of HIP 11915 b marked a significant breakthrough in the astronomy news. Because of its orbital distance and mass are just about the same as Jupiter, astronomers began to predict that star systems with Jupiter-like planets at the right orbital distance could have terrestrial planets in the inner portion, like the Solar System does. While several Jovian-sized planets have been discovered, most have been found orbiting close to their stars. It is now hypothesized that Jupiter's movement in the Solar System may have cleared the way for the rocky inner planets, including Earth, to form. The similarity extends to the star that centers the system; like the Sun, HIP 11915 is a G-class star.

Solar System similarities According to Jorge Meléndez, who led the University of São Paulo, Brazil team that discovered HIP 11915 b, "the quest for an Earth 2.0, and for a complete Solar System 2.0, is one of the most exciting endeavors in astronomy". This means that there is the chance that HIP 11915 may have undetected terrestrial planets closer in, at a distance ranging from 0.5–1.6 AU. The possibilities even extend outwards for the chance of a habitable Earth-like planet to form around 1 AU. Megan Bedell, from the University of Chicago and lead author of the paper, concludes: “After two decades of hunting for exoplanets, we are finally beginning to see long-period gas giant planets similar to those in our own Solar System thanks to the long-term stability of planet hunting instruments like HARPS. This discovery is, in every respect, an exciting sign that other solar systems may be out there waiting to be discovered.”

Illustrations

Worked examples

Example 1 — a first encounter with HIP 11915 b

Start with the simplest possible case. Write down what HIP 11915 b 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 HIP 11915 b 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 HIP 11915 b 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 HIP 11915 b

In research: HIP 11915 b 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 HIP 11915 b 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: HIP 11915 b is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cetus (constellation), Exoplanets discovered in 2015, so understanding it makes those chapters shorter.
In everyday life: Look for HIP 11915 b 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 HIP 11915 b in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HIP 11915 b 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 HIP 11915 b out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HIP 11915 b in simple terms?

Why does HIP 11915 b 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 HIP 11915 b?

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 HIP 11915 b.