For the first time, astronomers have directly photographed various planets orbiting a sun-like star.
The European Southern Observatory Very large telescope (VLT) in Chile photographed two giant planets circling TYC 8998-760-1, a very young analogue of our own sun that is about 300 light-years from Earth, a new study reports.
“This discovery is a snapshot of an environment that is very similar to our solar systembut at a much earlier stage of its evolution, “the study’s lead author Alexander Bohn, a doctoral student at Leiden University in the Netherlands, said in a statement.
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Prior to this historic cosmic portrait, only two multi-planet systems had been directly photographed, and none of them feature a sun-like star, study team members said. And take a photo of even a single one exoplanet it is still a rare achievement.
“Although astronomers have indirectly detected thousands of planets in our galaxy, only a small fraction of these exoplanets have been directly photographed,” study co-author Matthew Kenworthy, an associate professor at Leiden University, said in the same statement.
Bohn, Kenworthy and their colleagues studied the 17-million-year-old star TYC 8998-760-1 with the VLT Spectro-Polarimetric high-contrast exoplanet research instrument, or SPHERE for short. SPHERE uses a device called a coronagraph to block blinding light from a star, allowing astronomers to see and study planets in orbit that would otherwise be lost in the glow.
The recently reported SPHERE images revealed two planets in the system, TYC 8998-760-1b and TYC 8998-760-1c. Astronomers already knew about TYC 8998-760-1b, a team led by Bohn announced its discovery late last year – but TYC 8998-760-1c is a new world.
The two planets are huge and distant. TYC 8998-760-1b is approximately 14 times more massive than Jupiter and orbits at an average distance of 160 astronomical units (AU), and TYC 8998-760-1c is six times heavier than Jupiter and is about 320 AU from the host star. (An AU is the average distance from Earth to the Sun – approximately 93 million miles, or 150 million kilometers. To compare: Jupiter and Saturn’s orbit our sun only 5 UA and 10 UA, respectively.)
It is unclear if the two worlds at TYC 8998-760-1 were formed in their current locations or if they were expelled in any way. Additional observations, including those made by huge future observatories such as the European Extremely Large Telescope (ELT), could help solve that mystery, study team members said.
There are also other questions about the TYC 8998-760-1 system. For example, do the two gas giants have company? Could several rocky planets circulate relatively close to the star, as they do in our solar system?
“The possibility that future instruments, such as those available in the ELT, can detect even lower-mass planets around this star mark an important milestone in the understanding of multi-planet systems, with possible implications for the history of our own solar system” . Bohn said.
the new study It was published online today (July 22) in The Astrophysical Journal Letters.
Mike Wall is the author of “Out There” (Grand Central Publishing, 2018; illustrated by Karl Tate), a book on the search for extraterrestrial life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.
