How Many Additional Exoplanets are in Known Systems?

An illustration of TESS. Credit: NASA

One thing we’ve learned in recent decades is that exoplanets are surprisingly common. So far, we’ve confirmed nearly 6,000 planets, and we have evidence for thousands more. Most of these planets were discovered using the transit method. though we there are other methods as well. Many stars are known to have multiple planets, such as the TRAPPIST-1 system with seven Earth-sized worlds. But even within known planetary systems there could be planets we’ve overlooked. Perhaps their orbit doesn’t pass in front of the star from our vantage point, or the evidence of their presence is buried in data noise. How might we find them? A recent paper on the arXiv has an interesting approach.

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Exoplanet Discovered in a Binary System Could Explain Why Red Dwarfs Form Massive Planets

This artist's concept illustrates a red dwarf star surrounded by exoplanets. Credit: NASA/JPL-Caltech

In recent years, the number of known extrasolar planets (aka. exoplanets) has grown exponentially. To date, 5,799 exoplanets have been confirmed in 4,310 star systems, with thousands more candidates awaiting confirmation. What has been particularly interesting to astronomers is how M-type (red dwarf) stars appear to be very good at forming rocky planets. In particular, astronomers have detected many gas giants and planets that are several times the mass of Earth (Super-Earths) orbiting these low-mass, cooler stars.

Consider TOI-6383A, a cool dwarf star less than half the mass of the Sun that orbits with an even smaller, cooler companion – the red dwarf star TOI-6383B. In a recent study, an international team of astronomers with the Searching for Giant Exoplanets around M-dwarf Stars (GEMS) survey detected a giant planet transiting in front of the primary star, designated TOI-6383Ab. This planet is similar in size and mass to the system’s companion star, which raises questions about the formation of giant planets in red dwarf star systems.

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TESS Finds a Triple Star System that Could Fit within Mercury’s Orbit

This artist’s concept illustrates how tightly the three stars in the system called TIC 290061484 orbit each other. If they were placed at the center of our solar system, all the stars’ orbits would be contained a space smaller than Mercury’s orbit around the Sun. The sizes of the triplet stars and the Sun are also to scale. NASA’s Goddard Space Flight Center

TESS, the Transiting Exoplanet Survey Satellite has been on the lookout for alien worlds since 2018. It has just hit the news again having identified an extreme triple star system where two stars orbit each other every 1.8 days. The third component circles them both in 25 days – this puts the entire system within the orbit of Mercury with a little wriggle room to spare! To visual observers, it looks like a single star but the power of TESS revealed a flicker as the stars line up and pass one another along our line of sight. Eventually, the two inner stars will merge, triggering a supernova event!

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A Mini-Neptune in the Habitable Zone in a Binary Star System

Sometimes, it seems like habitable worlds can pop up almost anywhere in the universe. A recent paper from a team of citizen scientists led by researchers at the Flatiron Institute might have found an excellent candidate to look for one – on a moon orbiting a mini-Neptune orbiting a star that is also orbited by another star.

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A New Venus-Sized World Found in the Habitable Zone of its Star

The parade of interesting new exoplanets continues. Today, NASA issued a press release announcing the discovery of a new exoplanet in the Gliese 12 system, sized somewhere between Earth and Venus and inside the host star’s habitable zone. Two papers detail the discovery, but both teams think that the planet is an excellent candidate for follow-up with the James Webb Space Telescope (JWST) to try to tease out whether it has an atmosphere and, if so, what that atmosphere is made of.

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TESS Finds its First Rogue Planet

This illustration shows a rogue planet traveling through space. Credit: NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

Well over 5,000 planets have been found orbiting other star systems. One of the satellites hunting for them is TESS, the Transiting Exoplanet Survey Satellite. Astronomers using TESS think they are made a rather surprising discovery; their first free-floating – or rogue – planet. The planet was discovered using gravitational microlensing where the planet passed in front of a star, distorting its light and revealing its presence.

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The SETI Ellipse Tells Us Where to Search for Extraterrestrial Civilizations

The SETI Ellipsoid (Image credit: Zayna Sheikh)

Of all the questions that remain unanswered, the question of life in the Universe is surely the one that captures our attention the most. In a Universe whose observable edge is 46 billion light years away, is it even conceivable that we are alone, the sole planet among the millions and perhaps billions that are out there, where life has evolved, an oasis of life in the cosmic ocean. In the search for alien civilisations, researchers have proposed that it may be possible to use bright galactic events like supernovae to act as a focal point for civilisations to announce their presence! 

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Six Planets Found Orbiting an Extremely Young Star

Artist rendering of the TOI-1136 system and its young star flaring. Credit: Rae Holcomb/Paul Robertson/UCI

The field of exoplanet study continues to grow by leaps and bounds. As of the penning of this article, 5,572 extrasolar planets have been confirmed in 4,150 systems (with another 10,065 candidates awaiting confirmation. Well, buckle up because six more exoplanets have been confirmed around TOI-1136, a Sun-like star located roughly 276 light-years from Earth. This star is less than 700 million years old, making it relatively young compared to our own (4.6 billion years). This system will allow astronomers to observe how systems like our own have evolved with time.

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Exoplanets: Why study them? What are the challenges? What can they teach us about finding life beyond Earth?

Credit: NASA/W. Stenzel

Universe Today has explored the importance of studying impact craters and planetary surfaces and what these scientific disciplines can teach us about finding life beyond Earth. We learned that impact craters are caused by massive rocks that can either create or destroy life, and planetary surfaces can help us better understand the geologic processes on other worlds, including the conditions necessary for life. Here, we will venture far beyond the confines of our solar system to the many stars that populate our Milky Way Galaxy and the worlds they orbit them, also known as exoplanets. We will discuss why astronomers study exoplanets, challenges of studying exoplanets, what exoplanets can teach us about finding life beyond Earth, and how upcoming students can pursue studying exoplanets, as well. So, why is it so important to study exoplanets?

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Half of this Exoplanet is Covered in Lava

Like Kepler-10 b, illustrated above, the exoplanet HD 63433 d is a small, rocky planet in a tight orbit of its star. HD 63433 d is the smallest confirmed exoplanet younger than 500 million years old. It's also the closest discovered Earth-sized planet this young, at about 400 million years old. NASA/Ames/JPL-Caltech/T. Pyle

Astronomers working with TESS (Transiting Exoplanet Survey Satellite) have discovered a planet that’s been left out in the Sun too long. Or at least half of it has. The newly discovered planet is tidally locked to its star, and one side is completely molten.

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