Astronomers make thrilling discovery of three super-Earth exoplanets in orbit around nearby starThree rocky exoplanets larger than the Earth have been discovered in orbit around the nearby orange dwarf star designated as HD 48498.
The planets orbit the host star in seven, 38 and 151 days.
The outermost of the three worlds resides in the habitable zone of its host star, which means that liquid water can exist on the surface.
The discovery makes HD 48498 the closest known star system to host a super-Earth in the habitable zone around a Sun-like star.
Radial velocity measurements track the subtle movements of the star, caused by the planets in orbit around it.
Astronomers make thrilling discovery of three super-Earth exoplanets in orbit around nearby star
Three rocky exoplanets larger than the Earth have been discovered in orbit around the nearby orange dwarf star designated as HD 48498.
Artistic impression of the HD 48948 system. (Image Credit: Soumita Samanta).
New Delhi: Astronomers have discovered three exoplanet candidates in orbit around an orange dwarf star nearby, designated as HD 48498, at a distance of around 55 lightyears from the Earth. These three worlds can potentially be Super-Earth, or terrestrial worlds that are larger than the Earth. The planets orbit the host star in seven, 38 and 151 days. The outermost of the three worlds resides in the habitable zone of its host star, which means that liquid water can exist on the surface.
The discovery makes HD 48498 the closest known star system to host a super-Earth in the habitable zone around a Sun-like star. The discovery of the system is an exciting step towards finding habitable exoplanets in orbits around Sun-like stars. These Super-Earth have a mass greater than that of Earth, but much less than the ice giants in the Solar System, Uranus and Neptune.
Radial Velocity measurements
The exoplanets were identified through the HARPS-N Rocky Planet Search Programme. The researchers collected 190 high-precision radial velocity measurements over a period of ten years. Radial velocity measurements track the subtle movements of the star, caused by the planets in orbit around it. The wobbles induced by the gravitational influence of the planets cause the host star to move slight farther away or closer to the Earth, movements that can be detected by precisely examining the light from the host star.
The research reveals three candidate exoplanets with masses ranging from 5 to 11 times that of the Earth. The proximity of the target makes the system a great target for future high-contrast direct imaging of the system, and conducting high-resolution spectroscopic studies. The discovery paves the way for better understanding other planetary systems, and the potential for life beyond the Solar System.
A paper describing the findings has been published in the Monthly Notices of the Royal Astronomical Society. Lead author of the research, Shweta Dalal says, “This discovery highlights the importance of long-term monitoring and advanced techniques in uncovering the secrets of distant star systems. We are eager to continue our observations and look for additional planets in the system.”
