Exoplanet Discovery: NASA's Hubble Space Telescope Witnesses Growing, Feeding Giant Planet

The Hubble Space Telescope at NASA has captured something extraordinary: a still-forming giant planet feeding off debris and material around a young star. Imagine a Jupiter-sized object, yet still in its infancy, absorbing material surrounding it and a young star.

The exoplanet, designated PDS 70b, is orbiting the orange dwarf known as PDS 70. This dwarf star has been previously known to have two "actively forming planets" inside an extremely huge disk made of dust and gas around this orange dwarf star. Both PDS 70 and its still-forming PDS 70b are found within the constellation Centaurus, some 370 light-years from Earth.

Finding Exoplanets, Including Infant Ones

"We just don't know very much about how giant planets grow," says Brendan Bowler, an associate professor in the Department of Astronomy at The University of Texas at Austin, in the latest NASA news release.

He adds that the PDS 70 system gives the researchers the first chance to "witness material falling onto a planet," with the results from this Hubble Space Telescope opening a new area into this particular field of study.

NASA reports that more than 4,000 exoplanets have been reported so far. However, only 15 of these objects have been directly imaged by telescopes like the Hubble Space Telescope. Additionally, these planets are mostly so far away from Earth that these objects only appear as dots, even in the highest resolution images available.

However, researchers behind this new discovery employed a novel method, directly imaging PDS 70b and opening a new possibility for advancing studies on exoplanets.

"This system is so exciting because we can witness the formation of a planet," comments Yifan Zhou, a postdoctoral fellow at the McDonald Observatory and also from the University of Texas at Austin. He also notes that this discovery is the "youngest bona fide planet" that has been imaged by the Hubble Space Telescope - at a "youthful" five million years old. Young by astronomical standards, PDS 70b continues to build mass and absorb material surrounding its host star.

Utilizing Hubble's UV Light Observations

Zhou also pointed out a feature of the Hubble Space Telescope - its ultraviolet (UV) light - that captures a unique visualization of radiation from the hot gasses falling into the planet. This offered insight into the rate at which PDS 70b is growing in mass.

These UV-based observations add to the body of research on the exoplanet. It also allowed the researchers to directly measure the rate of change in the planet's mass for the first time. The exoplanet on the Centaurus constellation is already five times as massive compared to Jupiter, at only a period of five million years. Researchers assume, based on its measured growth rate should it remain stable for another million years, PDS 70b would have an additional mass equivalent to 1/100th of Jupiter's.

Based on the recent observation, the entire PDS 70 system is filled with a disk of primordial gas and dust, fueling the needs of its growing and potentially forming exoplanets in the future. PDS 70b is particularly surrounded by its own gas-and-dust material that drains from the larger circumstellar disk outside it.

Researchers report their findings in the article "Hubble Space Telescope UV and Hα Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b," appearing in the latest The Astronomical Journal.

Check out more news and information on the Hubble Space Telescope in Science Times.