By Vishal Goel, | January 08, 2017
The star HD 172555 is part of the Beta Pictoris Moving Group. (YouTube)
NASA's Hubble Space Telescope has discovered exocomets (comets outside the solar system) plunging onto a 23 million years old star named "HD 172555," at around 95 light-years away from Earth.
According to the scientists, the presence of these comets provides circumstantial evidence of "gravitational stirring" by an unseen Jupiter-sized planet that deflects these comets and hurls them into the star.
Like Us on Facebook
The exocomets, not seen around the star, were found after gas was detected, which is likely the vaporized remnants of their icy nuclei.
HD 172555 is one of the extrasolar systems where astronomers have detected wayward comets. All the systems are young, under 40 million years old. Such events also provide new insights into the past and present activity of comets in our solar system. For instance, infalling comets could have transported water to Earth and other inner planets of our solar system.
The star HD 172555 is part of the Beta Pictoris Moving Group, a collection of stars born from the same stellar nursery. It is the second group member found to harbor such comets. The stellar group is the closest collection of young stars to Earth. The grouping is at about the age that it should be building terrestrial planets, said study leader Carol Grady of Eureka Scientific Inc. in Oakland, California.
A team of French astronomers first discovered exocomets transiting HD 172555 in data gathered between the years 2004 and 2011 by the European Southern Observatory's HARPS (High Accuracy Radial velocity Planet Searcher) planet-finding spectrograph. The HARPS spectrograph detected calcium footprints imprinted in the starlight, suggesting that comet-like objects were falling into the star. After that, Grady's team used Hubble's Space Telescope Imaging Spectrograph (STIS) and the Cosmic Origins Spectrograph (COS) in 2015 to conduct a spectrographic analysis in ultraviolet light, which allows Hubble to identify the signature of certain elements.
Hubble detected silicon and carbon gas in the starlight moving at about 360,000 miles per hour across the face of the star. The most likely explanation for this is that Hubble saw material from comet-like objects that broke apart after streaking across the face of the star, said Grady.
'Diablo 3' Expansion: Blizzard Confirms Returning, New Add-ons in Rise of the Necromancer DLC; Release Date This Spring?
Deep Sea Secrets: The Mystery of the Tully Monster Unveiled; What We Know so far
AMD Ryzen Release Date, Specs: Leaks Show new AMD Ryzen Architecture Details, Motherboards From Biostar, Gigabyte and Asus
‘Overwatch’ Season 4 Looms Amid the Pending Conclusion of Season 3 Competitive Play
Study: Having a cat Does not Cause Mental Health Problems
How Alien Cosmic Rays Impact Phones, Planes, and even Election Results
NASA: Carbon Levels on Mars not Enough to Make Water Flow
Why do we Need to Sleep? To Forget and Preserve Memories
Drug Syndicates Use WhatsApp, WeChat to Sell, Recruit Children in Malaysia
Mathematician Proposes to Use Sound Waves to Stop Tsunamis