Planet AB Aurigae b is still in its "birthing" stages. But astronomists say it is already nine times the mass of Jupiter and it's forming in a unusual way.
An illustration of AB Aurigae b, a giant gas planet discovered with the help of the Subaru Telescope and Hubble Space TelescopeImage: NASA/ESA/Joseph Olmsted (STScI)/REUTERS
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AB Aurigae b is still only a baby as far as planets go. It's a giant gas planet that scientists have discovered in the early stages of its formation. And it's already breaking records in astronomy. Astronomers say the planet is nine times the mass of Jupiter — and that it is challenging our understanding of how planets form.
Jupiter is our solar system's largest planet. It has a mass that's almost 320 times that of Earth and more than two-and-a-half times that of all the other planets in our solar system combined. It is, in other words, pretty darn heavy.
But AB Aurigae b makes Jupiter look like a little balloon.
"We think it is still very early on in its 'birthing' process," astrophysicist Thayne Currie of the Subaru Telescope and the NASA Ames Research Center told news agency Reuters.
"Evidence suggests that this is the earliest stage of formation ever observed for a gas giant," said Currie.
Gas giants have a small solid core. But they are mostly made up of gasses — hydrogen and helium — that swirl around that core.
Our solar system has two gas giants: Jupiter and Saturn. The Earth and Mars, for comparison, are known as rocky planets.
A planet with a massive host star
Researchers detected the new gas giant with the help of two telescopes — one on the ground and one orbiting Earth.
The Subaru telescope is located near the summit of an inactive Hawaiian volcano and the Hubble Space Telescope is in a low-Earth orbit.
As the scientists would have expected, AB Aurigae b has a star. When planets form they tend to have a host star. Planets orbit stars. And in this case, the star is called AB Aurigae.
It is itself a very young star. AB Aurigae is only about 2 million years old, whereas our sun (also a star) is roughly 4.5 billion years old.
A disc surrounds a newly discovered planet's host star, AB AurigaeImage: ESO/UPI Photo/Newscom/picture alliance
The planet is embedded in an expansive disk of gas and dust. Planets form from the materials in these disks, with small objects like grain and rocks swirling around, colliding and sticking together.
All that is quite normal. But there is something unusual about the planet and its star.
A planet and star far apart
The planet and its star seem to be far too far apart for any of those swirling bits to stick and form the planet.
AB Aurigae b is three times as far away from its star as Neptune is from our star, the sun. That's three times the distance that astronomers normally observe.
"This process cannot form giant planets at large orbital distance, so this discovery challenges our understanding of planet formation," Olivier Guyon, an astronomer at the Subaru telescope and the University of Arizona, told Reuters.
The researchers believe that the planet may have formed when the disc around its host star cooled and gravity caused it to fragment into one or more clumps ― one of which turned into the planet.
"There's more than one way to cook an egg," Currie said. "And apparently there may be more than one way to form a Jupiter-like planet."
Edited by: Zulfikar Abbany
Earth-like planets and other celestial discoveries
Astronomers have found a new Earth-like planet in our neighboring solar system, Proxima Centauri. We take a look at this and other discoveries from Earth- and space-based telescopes.
Image: L. Calçada/ESO
Another planet Earth?
The European Southern Observatory (ESO) has discovered a third Earth-like planet orbiting the star Proxima Centauri, the closest star to our sun at four light years away. A planet is considered Earth-like if scientists suspect it provides conditions that could make life theoretically conceivable, such as a certain temperature range, gravity, an atmosphere and the possibility of water.
Image: L. Calçada/ESO
Discovery via the Very Large Telescope
Astronomers discovered the planet through the Very Large Telescope (VLT) in Chile's Atacama Desert. Proxima d is the lightest of the three planets discovered around our closest star. ESO researchers also discovered the somewhat larger Proxima b, but with a different telescope supported by the planet-search instrument HARPS.
Image: ESO/G. Lombardi
Spaceship Kepler: On the hunt for planets
Many Earth-like planets haven't been discovered by telescopes situated on Earth but by ones in space. Spaceship Kepler has been searching for Earth-like planets since 2009. Besides meeting the physical conditions, they must also consist of rock or metal compounds and have a solid surface, in contrast to gas giants like Jupiter and Saturn.
Image: NASA Ames/JPL-Caltech/T Pyle
A longer distance away
Exoplanet Kepler-186f is located 500 light years away from us, orbiting red dwarf Kepler-186. That small sun has only about 4% of the energy of our sun. Kepler-186f orbits Kepler-186 at a perfectly calibrated distance: Water would neither freeze nor evaporate on the planet, which is a precondition for life. But the question of whether there is water on Kepler-186f at all remains unanswered.
There are no detailed pictures of exoplanets, just artistic representations like this one of Kepler-186f. But not even a drawing exists of another recently discovered exoplanet, Kepler-438b, which orbits a sun-like star about 470 light years away from Earth and is just slightly larger than our planet. NASA published the discovery on January 6, 2014.
Image: picture-alliance/dpa
Ocean-covered giants?
This artist's drawing of Kepler-62e shows a planet covered by ocean. Scientists agree that Earth-like exoplanets most likely have large oceans. Kepler-62e can be found in the constellation of Lyra, located 1,200 light years away from us. And its mother star, Kepler-62, has yet another Earth-like planet ...
Image: NASA Ames/JPL-Caltech
The Kepler-62 brothers
... Kepler-62f, whose diameter is 1.4 times that of Earth. The Earth-like planet is located a bit further out in its solar system than its larger brother Kepler-62e, which is 1.61 times as big as Earth. Both may be suited for life. Researchers believe that the existence of rocks and water is plausible.
Image: NASA Ames/JPL-Caltech
Orbiting two suns
Even though Kepler-16b is located on the edge of an inhabitable zone, it probably doesn't host any life. This is a pity, because the planet orbits two suns — every morning and evening, its inhabitants would be able to observe two sunrises and sunsets! Too bad Kepler-16b is most likely a gas planet, composed of rock and ice — not good for beings needing to breathe fresh air.
Image: imago/UPI Photo
The Hubble Space Telescope offers many perspectives
The Pillars of Creation are located in the Eagle Nebula about 7,000 light years away. The joint ESA and NASA Hubble Space Telescope took new pictures of the formation through an infrared light spectrum. The pillars are home to numerous bright and young stars, including entire solar systems.
Image: NASA, ESA/Hubble and the Hubble Heritage Team
Lights on!
The same picture through visible light: more fog, but also more color. Dust and gas in the pillars are pierced by radiation originating from young stars. These new Hubble Telescope pictures enable researchers to monitor changes in the formation over a longer period of time.
Image: NASA, ESA/Hubble and the Hubble Heritage Team
A star is born
NGC 4102 is a LINER galaxy: a low-ionization nuclear emission-line region. This means it emits ionized radiation, like roughly one-third of all galaxies. At its center, there is a sun-burst region, where young stars seem to be born. It has a diameter of about 1,000 light years. Scientists don't understand the exact processes in the center yet.
Image: ESA/Hubble, NASA and S. Smartt (Queen's University Belfast)
A messier cluster
This cluster of stars, located in the northern part of the Hercules formation, is called Messier 92. On dark nights with clear skies, we can see it from Earth with bare eyes. The cloud includes roughly 330,000 stars, most of which consist of hydrogen and helium. Heavier elements like metals are rare.
Image: ESA/Hubble & NASA/Gilles Chapdelaine
The best view of Andromeda
The original version of this photo of the Andromeda Galaxy is 1.5 billion pixels in size — the most detailed picture ever taken of that galaxy. It includes 100 million stars and thousands of star clusters. To watch it in its entire beauty, one would need 600 HD-TV screens. The ends of the picture are 40,000 light years apart.
Image: NASA, ESA, J. Dalcanton (University of Washington, USA), B. F. Williams (University of Washington, USA), L. C. Johnson (University of Washington, USA), the PHAT team, and R. Gendler