astronomy

WASP-39b

WASP-39b 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 WASP-39b rather than just read about it. In short: WASP-39b, officially named Bocaprins, is a hot Jupiter extrasolar planet discovered in February 2011 by the WASP project, notable for containing a substantial amount of water in its atmosphere. In addition Bocaprins was the first exoplanet found to contain carbon dioxide in its atmosphere, and likewise for sulfur dioxide.

Key takeaways

WASP-39b belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect WASP-39b to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of WASP-39b from memory before moving on to harder problems.

Reference excerpt

WASP-39b, officially named Bocaprins, is a hot Jupiter extrasolar planet discovered in February 2011 by the WASP project, notable for containing a substantial amount of water in its atmosphere. In addition Bocaprins was the first exoplanet found to contain carbon dioxide in its atmosphere, and likewise for sulfur dioxide. Bocaprins orbits the star WASP-39 in the constellation Virgo, about 700 light-years from Earth. As part of the NameExoWorlds campaigns at the 100th anniversary of the IAU, the planet was named Bocaprins, after the beach Boca Prins in the Arikok National Park of Aruba.

Characteristics

Bocaprins has a mass of about 0.28 times that of Jupiter and a radius about 1.27 times that of Jupiter (91,000 km). It is a hot gas giant planet with a high temperature of 900 °C. The exoplanet orbits very close (7 million km) to WASP-39, its host star, every 4 days. Bocaprins is also notable for having an extremely low density, near that of WASP-17b. While WASP-17b has a density of 0.13±0.06 g/cm3, WASP-39b has a slightly higher density of 0.18±0.04 g/cm3.

Atmospheric composition

Hot water molecules were found in the atmosphere of Bocaprins in a 2018 study. The atmospheric transmission spectra, taken by different instruments, were inconsistent as in 2021, possibly indicating a disequilibrium atmospheric chemistry. High-fidelity spectra obtained by the James Webb Space Telescope in 2022 did not confirm a disequilibrium chemistry. Bocaprins is one of the James Webb Space Telescope's early release science targets. Sulfur dioxide was observed in this planet's atmosphere for the first time, or indeed of any planet outside of the Solar System, indicating the existence of photochemical processes in the atmosphere. Bocaprins is the first exoplanet in which carbon dioxide has been detected. Planetary transmission spectra taken in 2022 has indicated the atmosphere of Bocaprins is partially cloudy, and planet C/O ratio appears to be subsolar. The spectral signature of water, carbon dioxide, sodium and sulfur dioxide were also detected.

See also WASP-6b WASP-17b WASP-19b WASP-31b WASP-121b List of proper names of exoplanets (see section Sources in References) List of transiting exoplanets List of exoplanets discovered in 2011

References

Further reading Fischer, Patrick D.; Knutson, Heather A.; et al. (August 2016). "HST Hot-Jupiter Transmission Spectral Survey: Clear Skies for Cool Saturn WASP-39b". The Astrophysical Journal. 827 (1): 19. arXiv:1601.04761. Bibcode:2016ApJ...827...19F. doi:10.3847/0004-637X/827/1/19. Mancini, L.; Esposito, M.; et al. (May 2018). "The GAPS programme with HARPS-N at TNG. XVI. Measurement of the Rossiter-McLaughlin effect of transiting planetary systems HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60". Astronomy & Astrophysics. 613: A41. arXiv:1802.03859. Bibcode:2018A&A...613A..41M. doi:10.1051/0004-6361/201732234. Tsai, Shang-Min; Lee, Elspeth K. H.; et al. (May 2023). "Photochemically produced SO2 in the atmosphere of WASP-39b". Nature. 617 (7961): 483–487. arXiv:2211.10490. Bibcode:2023Natur.617..483T. doi:10.1038/s41586-023-05902-2. PMID 37100917. Carter, A. L.; May, E. M.; et al. (August 2024). "A benchmark JWST near-infrared spectrum for the exoplanet WASP-39 b". Nature Astronomy. 8 (8): 1008–1019. arXiv:2407.13893. Bibcode:2024NatAs...8.1008C. doi:10.1038/s41550-024-02292-x.

External links Media related to WASP-39b at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with WASP-39b

Start with the simplest possible case. Write down what WASP-39b 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 WASP-39b 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 WASP-39b 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 WASP-39b

In research: WASP-39b 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 WASP-39b 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: WASP-39b is common in secondary-school and first-year university syllabi. It links to neighbouring topics Exoplanets discovered by WASP, Exoplanets discovered in 2011, Exoplanets with proper names, so understanding it makes those chapters shorter.
In everyday life: Look for WASP-39b 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 WASP-39b in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what WASP-39b 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 WASP-39b out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is WASP-39b in simple terms?

Why does WASP-39b 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 WASP-39b?

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 WASP-39b.