A new exoplanet the size of Neptune is making the delight of astronomers as its gas cloud is unusually big and leaves and tails the planet in a comet-like fashion.
The exoplanet was discovered thanks to the Hubble Space Telescope as well as Chandra X-ray Observatory. Of course, the astronomers’ enthusiasm to look deeper and deeper into space helped.
The planet the size of Neptune, or GJ 436b as it was named is 33 light years away from Earth and has a mass 22 times that of our planet. Located in the Leo constellation, GJ 436b was found to orbit an intensely red dwarf star and to be blanketed in a massive gaseous cloud.
The similarity to a comet stems from the fact that the gas cloud prolongs way behind the exoplanet in a comet-like tail.
It is a delight indeed for astronomers and an exciting one as GJ436b is the first exoplanet of its kind ever revealed.
David Ehrenreich of the University of Geneva, Switzerland expressed his surprise:
“I was astonished by the mere size of the cloud of gas escaping from the planet”.
From this perspective, GJ 436b could be compared to a warm Neptune. More than ten times the mass of Earth, the comet-like exoplanet is closer to the star it orbits than Mercury for instance is to the Sun.
GJ 436b orbits 33 times closer to the dwarf red star than Earth orbits the Sun. Compared to Mercury, the exoplanet is 13 times closer to its star.
Based on the data retrieved from NASA’s Hubble Space Telescope, GJ 436b’s gas cloud is mainly composed of hydrogen, with a circular head measuring 1.8 million miles in diameter surrounding the planet and a long trail lagging behind.
The diameter of the circular head is five times that of the host star. It is still unclear what the exact length of the tail is, as the retrieved data did not cover it wholly. Nonetheless, computer models designed to increase the accuracy of calculations indicate that the gas tail’s length is approximately 9.3 million miles.
This massive comet-like exoplanet is estimated to release 1,000 tons of gas per second at current rates. Every billion years, GJ 436b will be losing 0.1 percent of the gaseous atmosphere. The depletion rate currently is sufficiently slow so that the exoplanet’s atmosphere would last longer than its red star’s lifetime.
Based on these findings, another team of researchers suggested that in fact GJ 436b’s atmosphere is not hydrogen-rich, but helium. This assumption is not consistent with the rate of depletion that Ehrenreich’s team calculated.
Had this been the case, the exoplanet’s atmosphere would have been fully depleted by now.
Nonetheless, further insight is expected with regards to both the comet-like exoplanet and others alike with the upcoming space missions from NASA and ESA.
NASA’s TESS mission and ESA’s CHEOPS and PLATO are expected to return an abundance of such data and one of a kind findings.
Image Source: nasa.gov