HAT-P-3b
A transiting exoplanet with a heavy-element core similar to HD 149026 b.
HAT-P-3b, also called Teberda, is a planet about 450 light-years away in Ursa Major, orbiting the star HAT-P-3. It was discovered in 2007 by the HATNet Project using the transit method, and later confirmed with Doppler spectroscopy. The planet's mass and radius are known precisely, and based on these measurements, its core is thought to contain roughly 75 Earth masses of heavy elements, a trait it shares with HD 149026 b.
The name Teberda comes from a mountain river in the Dombay region of Russia, chosen during the NameExoWorlds campaign on the 100th anniversary of the IAU. In 2013, the Spitzer Space Telescope observed the planet photometrically, finding it has a nearly circular orbit and a low albedo.
The discovery was made using the 11 cm aperture HAT-5 telescope at the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona. Follow-up radial velocity observations with the 1.5 m Tillinghast reflector ruled out the possibility that the brightness dips were from an eclipsing binary. Final confirmation came from the W. M. Keck Observatory, where the HIRES spectrograph measured the planet's mass and orbital parameters.
Quick Facts
- Discoverer
- HATNet Project
- Discovered
- 28 July 2007
- Discovery Method
- Transit
- Apsis
- astron
- Inclination
- 87.24
- Time Periastron
- 2454218.7598 ± 0.0029
- Semi-Amplitude
- 89.1 ± 2.0
- Star
- HAT-P-3
- Density
- 1060 ±
Facts from the source article.
Lore & Background
HAT-P-3b was discovered in 2007 by the HATNet Project via the transit method and confirmed with Doppler spectroscopy, so both its mass and radius are known quite precisely. The discovery was made with the 11 cm aperture HAT-5 telescope at the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona. Follow-up radial velocity observations with the 1.5 m Tillinghast reflector ruled out the possibility that the observed decrease in brightness was caused by an eclipsing binary, and final confirmation came from the W. M. Keck Observatory using the HIRES spectrograph to measure the mass and orbital parameters.
The planet is named Teberda, a name selected in the NameExoWorlds campaign by Russia during the 100th anniversary of the IAU. Teberda is a mountain river in the Dombay region, which is also the name of the host star HAT-P-3. In 2013, the Spitzer Space Telescope photometrically observed the planet, characterizing its near-zero eccentricity and low albedo.
Reader's Guide
HAT-P-3b's significance lies in its well-characterized mass and radius, which allowed astronomers to infer a substantial core of heavy elements—about 75 Earth masses. This places it in a category with HD 149026 b, another planet known for a massive core. The precise measurements were made possible by combining transit photometry with Doppler spectroscopy, a standard approach for confirming exoplanets. The planet's near-zero eccentricity and low albedo, as observed by the Spitzer Space Telescope in 2013, further refined its physical model. Its naming through the NameExoWorlds campaign, chosen by Russia during the IAU's centennial, connects the exoplanet to the Teberda river in the Dombay region, reflecting the cultural dimension of astronomical discovery. The discovery itself demonstrated the capability of small-aperture telescopes like the HAT-5 to detect transiting exoplanets, with follow-up from larger observatories providing confirmation.
Did You Know?
- HAT-P-3b has about 75 Earth masses of heavy elements in its core.
- Spitzer Space Telescope observations in 2013 found its eccentricity to be near-zero and its albedo low.
Frequently Asked Questions
Who is HAT-P-3b?
HAT-P-3b, nicknamed Teberda, is a hot Jupiter-class exoplanet roughly 450 light-years away in the constellation Ursa Major. It circles its host star HAT-P-3 in just under three days, making it one of the closest-in transiting worlds we know.
How was HAT-P-3b discovered?
The HATNet Project first detected the planet in 2007 by watching the star dim slightly as the planet passed in front of it. That transit signal was later backed up by Doppler spectroscopy, which measured the star's wobble to confirm a companion.
What is special about HAT-P-3b's composition?
Because its mass and radius are both pinned down very precisely, models suggest the planet's core holds around 75 Earth masses of heavy elements. That makes it a close compositional cousin of HD 149026 b, one of the few transiting worlds with a comparably dense, metal-rich interior.
Where does the name Teberda come from?
During the IAU's NameExoWorlds campaign marking the organization's 100th anniversary, the public chose the name after a mountain river in the Dombay region of Russia. It gives the planet a terrestrial, river-inspired identity that contrasts with its scorching orbit.
Why is HAT-P-3b important to exoplanet science?
Its precisely measured mass and radius let researchers build a detailed interior model, showing that some hot Jupiters carry a surprisingly large heavy-element core. That makes it a key benchmark for testing planet-formation theories and for comparing against other dense transiting worlds like HD 149026 b.
More in Transiting Exoplanets, Part 5 1-24
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced