Kepler-173 b: A Super Earth Exoplanet in the Kepler Space Telescope’s Discoveries
Introduction
Kepler-173 b is an exoplanet located in the constellation Lyra, situated approximately 2,718 light-years from Earth. It was discovered in 2014 by NASA’s Kepler Space Telescope using the transit method of detection. This discovery adds to the growing catalog of exoplanets, particularly those that fall under the classification of “Super Earths.” These planets, often larger than Earth but smaller than Uranus or Neptune, provide intriguing possibilities for the study of planetary systems and the potential for habitability.
Kepler-173 b’s characteristics reveal it as an interesting object in the context of exoplanet research, particularly its size, orbital characteristics, and its placement within the broader parameters of planets discovered by the Kepler mission. The following article examines its key features, how it was discovered, and what makes it an important subject for scientific exploration.
Discovery and Detection
Kepler-173 b was discovered as part of NASA’s Kepler mission, which was designed to identify Earth-like planets in the habitable zones of distant stars. Kepler used a method known as the “transit method” to detect this exoplanet. This involves monitoring the brightness of a star and noting any periodic dimming caused by a planet passing in front of it (a transit).
Kepler-173 b’s discovery in 2014 was part of the mission’s ongoing effort to catalog planets outside of our solar system. The planet’s discovery provided valuable data on the nature of Super Earths and helped to refine our understanding of planet formation and the diversity of planetary types in the universe. With its relatively small size compared to other gas giants and large icy planets, Kepler-173 b is representative of the many planets that the Kepler mission found during its years of operation.
Characteristics of Kepler-173 b
Mass and Radius
Kepler-173 b is classified as a Super Earth, meaning it is a rocky exoplanet with a mass and radius greater than Earth’s. With a mass approximately 2.21 times that of Earth, it is not the largest Super Earth found by Kepler, but its size is significant enough to be considered a valuable subject for comparative planetology. Its radius is about 1.29 times that of Earth, indicating that while it is larger than Earth, it likely still has a solid surface, unlike gas giants like Jupiter or Neptune.
Orbital Characteristics
Kepler-173 b orbits its host star very closely, at an orbital radius of just 0.048 astronomical units (AU). To put this into perspective, one AU is the average distance between Earth and the Sun, so Kepler-173 b is much closer to its star than Earth is to the Sun. The planet completes one full orbit in just 0.0118 Earth years, or approximately 4.3 Earth days. Such a short orbital period places Kepler-173 b in the category of “ultra-short-period” planets.
This proximity to its star makes Kepler-173 b a likely candidate for high surface temperatures, as it would be subject to significant stellar radiation. As a result, the planet’s surface conditions would likely be inhospitable for life as we know it, unless it possesses an atmosphere that can help moderate the heat.
Orbital Eccentricity
Kepler-173 b has an orbital eccentricity of 0.0, which means its orbit is circular. This is an important detail because it suggests that the planet’s distance from its star remains constant throughout its orbit, leading to stable conditions over time. Planets with highly elliptical orbits can experience drastic changes in temperature and radiation as they move closer to and farther from their stars, which can affect their potential for habitability.
Stellar Magnitude and Host Star
The host star of Kepler-173 b is not one of the brightest stars in the sky, with a stellar magnitude of 14.357. This places it among the faint stars detectable by Kepler’s instruments but not visible to the naked eye. The host star is likely a red dwarf, a common type of star that is cooler and smaller than our Sun. Red dwarfs are known for having longer lifespans and can be stable for billions of years, which provides an extended window for the study of planets that orbit them.
Super Earths: A Class of Exoplanets
The term “Super Earth” refers to a class of exoplanets that are more massive than Earth but lighter than Uranus or Neptune. These planets typically have masses ranging from 1 to 10 Earth masses. Super Earths are intriguing to scientists because they represent a middle ground between smaller, rocky planets like Earth and larger, gas-dominated planets like Neptune.
Kepler-173 b, with its mass of 2.21 Earth masses, fits comfortably within this category. Super Earths are significant because they offer a better understanding of how planets of various sizes form and how their atmospheres and climates behave. Some Super Earths may even be located in the habitable zone of their stars, where liquid water could potentially exist. While Kepler-173 b is not in a habitable zone, the study of similar Super Earths could provide insights into what types of conditions might support life elsewhere in the universe.
The Importance of Kepler-173 b in the Study of Exoplanets
Kepler-173 b, like other exoplanets discovered by the Kepler mission, provides vital data for astronomers and planetary scientists. By studying planets like Kepler-173 b, scientists can learn more about the variety of planetary systems in the universe and how different factors such as mass, size, and proximity to their stars influence a planet’s characteristics.
Super Earths like Kepler-173 b are particularly important because they offer insights into planetary atmospheres and the potential for future exploration. While Kepler-173 b is likely too hot and hostile to support life, it can serve as a model for studying more temperate Super Earths in the future.
The close proximity of planets like Kepler-173 b to their stars also makes them ideal candidates for more detailed observation with next-generation telescopes such as the James Webb Space Telescope (JWST). The JWST’s advanced capabilities in infrared observation will allow scientists to study the atmospheres of exoplanets like Kepler-173 b, potentially detecting signs of atmospheric composition, weather patterns, and even biomarkers that might suggest conditions conducive to life.
Future Exploration and Research
The study of exoplanets, particularly Super Earths like Kepler-173 b, is far from over. With the advancement of astronomical technology and the continued operation of space telescopes like Kepler and the JWST, researchers are poised to learn much more about the nature of these distant worlds. Understanding planets like Kepler-173 b is essential for building a more complete picture of planetary formation, composition, and evolution.
In addition to direct observation, future missions may attempt to study the star-planet interactions and gather more data on the physical conditions on planets similar to Kepler-173 b. This information could help scientists refine models of planetary climates and assess the broader implications for the potential habitability of planets in the future.
Conclusion
Kepler-173 b offers a fascinating glimpse into the diversity of exoplanets beyond our solar system. Its classification as a Super Earth, its close orbit around its star, and its relatively small size make it an excellent subject for study. While it is not a candidate for habitability, its discovery provides critical insights into the many types of planets that exist in the galaxy. The continued study of such planets will help us refine our understanding of planetary systems and expand the search for life beyond Earth.
As space telescopes continue to evolve, discoveries like Kepler-173 b will fuel further research and inspire new questions about the nature of planets and the possibility of life on worlds far beyond our own.