Qatar-3b
A dense hot Jupiter on a 2.5-day orbit.
Qatar-3b is a hot Jupiter exoplanet orbiting the G-type star Qatar-3, located in the northern constellation Andromeda. It is notable for being one of the densest planets discovered, with a mass 4.31 times that of Jupiter but a similar radius, resulting in a density of 4.0 g/cm³. The planet was discovered in 2016 by the Qatar Exoplanet Survey (QES), which also announced Qatar-4b and Qatar-5b at the same time.
Quick Facts
- Extrasolarplanet
- yes
- Apsis
- astron
- Discoverer
- Alsubai et al. 2019
- Discovered
- 2016
- Discovery Method
- Transit
- Eccentricity
- 0
- Period
- 2.5079204 d
Facts from the source article.
Lore & Background
Qatar-3b was discovered in 2016 by the Qatar Exoplanet Survey (QES), an international team based in Qatar. The survey simultaneously detected planets around Qatar-3, Qatar-4, and Qatar-5, using light curves of the host stars to confirm the transits and derive stellar properties. The planet orbits its star every 2.5 days, with a precisely measured period of 2 days, 12 hours, 11 minutes, and 24 seconds. Its orbit is perfectly circular, with an eccentricity of 0, and it lies at a distance of about 0.04 AU from its star—ten times closer than Mercury is to the Sun. The host star, Qatar-3, is a G-type star with 14.5% more mass and 27.2% larger radius than the Sun, a luminosity nearly double the Sun's, and an effective temperature of 5,991 K, giving it a yellow hue. The star rotates rapidly, completing a full rotation in 6.31 days, and has a metallicity similar to the Sun despite being described as metal poor.
Reader's Guide
Qatar-3b stands out among hot Jupiters for its exceptionally high density of 4.0 g/cm³, making it one of the densest exoplanets known. With a mass 4.31 times that of Jupiter but a comparable radius, its composition likely includes a substantial core of heavy elements. The planet's effective temperature of 1,681 K confirms it is a scorched world, heated intensely by its close proximity to the star. Its discovery as part of a trio of planets announced by the Qatar Exoplanet Survey in 2016 highlights the survey's role in finding transiting planets around bright stars. The circular orbit and short period of 2.5 days place Qatar-3b firmly in the category of typical hot Jupiters, yet its density challenges models of planetary structure, suggesting a compact interior. The host star's rapid rotation and metal-poor nature add context to the system's evolution. Qatar-3b remains a key object for studying the diversity of close-in giant planets and the processes that shape their physical properties.
More in Transiting Exoplanets, Part 4 1-24
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