Transit Method Archives

July 8, 2021July 8, 2021 by Matt Williams

There are Probably Many More Earth-Sized Worlds Than Previously Believed

This illustration depicts a planet partially hidden in the glare of its host star and a nearby companion star. After examining a number of binary stars, astronomers have concluded that Earth-sized planets in many two-star systems might be going unnoticed by transit searches, which look for changes in the light from a star when a planet passes in front of it. The light from the second star makes it more difficult to detect the changes in the host star’s light when the planet passes in front of it. Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva (Spaceengine)

In the past decade, the discovery of extrasolar planets has accelerated immensely. To date, 4,424 exoplanets have been confirmed in 3,280 star systems, with another 7,453 awaiting confirmation. So far, most of these planets have been gas giants, with about 66% being similar to Jupiter or Neptune, while another 30% have been giant rocky planets (aka. “Super-Earths). Only a small fraction of confirmed exoplanets (less than 4%) have been similar in size to Earth.

However, according to new research by astronomers working at NASA Ames Research Center, it is possible that Earth-sized exoplanets are more common than previously thought. As they indicated in a recent study, there could be twice as many rocky exoplanets in binary systems that are obscured by the glare of their parent stars. These findings could have drastic implications in the search for potentially habitable worlds since roughly half of all stars are binary systems.

June 25, 2021June 25, 2021 by Matt Williams

Aliens in 2,034 Nearby Star Systems Could use the Transit Method to see Earth

For centuries, human beings have speculated about the existence of planetary systems (much like our own) orbiting other stars. However, it has only been in the past few decades that scientists have been able to detect and study these distant worlds. To date, astronomers have used various methods to confirm the existence of 4,422 extrasolar planets in 3,280 star systems, with an additional 7,445 candidates awaiting confirmation.

Naturally, this raises some questions. If there is intelligent life out there that has similar capabilities to our own – and the same burning sense of curiosity – could it be watching us too? Equally important is the question of how many of be able to detect us. According to new research conducted by a team from Cornell and the American Museum of Natural History, there are 2,034 star systems within 326 light-years of Earth that would be watching us right now!

February 20, 2021February 20, 2021 by Matt Williams

Just Some of the Planets That TESS Has Found Nearby

Ever since NASA’s Kepler Space Telescope was launched in 2009, there has an explosion in the study of the extrasolar planets. With the retirement of Kepler in 2018, it has fallen to missions like the Transiting Exoplanet Survey Satellite (TESS) to pick up where its predecessor left off. Using observations from TESS, an international team of astronomers recently discovered three exoplanets orbiting a young Sun-like star named TOI 451.

February 1, 2021February 1, 2021 by Matt Williams

A Sunlike Star Found With Four (No, Five!) Exoplanets Orbiting It

This artist’s impression shows the view from the planet in the TOI-178 system found orbiting furthest from the star. New research by Adrien Leleu and his colleagues with several telescopes, including ESO’s Very Large Telescope, has revealed that the system boasts six exoplanets and that all but the one closest to the star are locked in a rare rhythm as they move in their orbits. Image Credit: ESO/L. Calçada/spaceengine.org

In just nine months (October 31st, 2021), NASA’s long-awaited James Webb Space Telescope (JWST) will finally be launched to space. Once operational, this next-generation observatory will use its powerful infrared imaging capabilities to study all kinds of cosmological phenomena. It will also be essential to the characterization of extrasolar planets and their atmospheres to see if any are habitable.

In anticipation of this, astronomers have been designating exoplanets as viable candidates for follow-up studies. Using data from the Transiting Exoplanet Survey Satellite (TESS), an international team led by MIT researchers discovered four new exoplanets orbiting a Sun-like star about 200 light-years from Earth. This system could be an ideal place for James Webb to spot a habitable planet.

October 21, 2020October 22, 2020 by Brian Koberlein

We use the Transit Method to Find other Planets. Which Extraterrestrial Civilizations Could use the Transit Method to Find Earth?

The three planets discovered in the L98-59 system by NASA’s Transiting Exoplanet Survey Satellite (TESS) are compared to Mars and Earth in order of increasing size in this illustration. Credit: NASA’s Goddard Space Flight Center

We have discovered more than 4,000 planets orbiting distant stars. They are a diverse group, from hot Jupiters that orbit red dwarf stars in a few days to rocky Earth-like worlds that orbit Sun-like stars. With spacecraft such as Gaia and TESS, that number will rise quickly, perhaps someday leading to the discovery of a world where intelligent life might thrive. But if we can discover alien worlds, life on other planets could find us. Not every nearby star would have a good view of our world, but some of them would. New work in the Monthly Notices of the Royal Astronomical Society tries to determine which ones.

September 2, 2020September 2, 2020 by Matt Williams

Machine Learning Algorithm Scoops up 50 New Exoplanets

Advances in technology are having a profound impact on astronomy and astrophysics. At one end, we have advanced hardware like adaptive optics, coronographs, and spectrometers that allow for more light to be gathered from the cosmos. At the other end, we have improved software and machine learning algorithms that are allowing for the data to be analyzed and mined for valuable nuggets of information.

One area of research where this is proving to be invaluable is in the hunt for exoplanets and the search for life. At the University of Warwick, technicians recently developed an algorithm that was able to confirm the existence of 50 new exoplanets. When used to sort through archival data, this algorithm was able to sort through a sample of candidates and determine which were actual planets and which were false positives.

July 16, 2020July 21, 2020 by Matt Williams

Do the TRAPPIST-1 Planets Have Atmospheres?

Most exoplanets orbit red dwarf stars because they're the most plentiful stars. This is an artist's illustration of what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right). Credits: NASA/JPL-Caltech

In February of 2017, the scientific community rejoiced as NASA announced that a nearby star (TRAPPIST-1) had a system of no less than seven rocky planets! Since that time, astronomers have conducted all kinds of follow-up observations and studies in the hopes of learning more about these exoplanets. In particular, they have been attempting to learn if any of the planets located in the stars Habitable Zone (HZ) could actually be habitable.

Many of these studies have been concerned with whether or not the TRAPPIST-1 planets have sufficient water on their surfaces. But just as important is the question of whether or not any have viable atmospheres. In a recent study that provides an overview of all observations to date on TRAPPIST-1 planets, a team found that depending on the planet in question, they are likely to have good atmospheres, if any at all.

March 4, 2020March 4, 2020 by Evan Gough

Are Low Density “Cotton Candy” Exoplanets Actually Just Regular Planets With Rings?

An artist’s conception of Piro and Vissapragada’s model of a ringed planet transiting in front of its host star. They used these models to constrain which of the known super-puffs could be explained by rings. Illustration is by Robin Dienel and courtesy of the Carnegie Institution for Science.

There’s a type of exoplanet that astronomers sometimes refer to as cotton candy planets, or super-puffs. They’re mysterious, because their masses don’t match up with their extremely large radii. The two characteristics imply a planet with an extremely low density.

In our Solar System, there’s nothing like them, and finding them in distant solar systems has been puzzling. Now a pair of astronomers might have figured it out.

January 30, 2020January 30, 2020 by Evan Gough

CHEOPS Just Opened Its Eyes to Start Studying Known Exoplanets, We Should See the First Picture in a Few Weeks

Artist's impression of CHEOPS © ESA / ATG medialab

The CHEOPS (CHaracterising ExOPlanets Satellite) spacecraft just opened the cover on its telescope. The spacecraft was launched on December 18th 2019 and has so far performed flawlessly. In one or two weeks we could get our first images from the instrument.

November 12, 2019November 12, 2019 by Evan Gough

Satellites Watched Mercury’s Transit From Space, Confirming That Yes, the Sun Has At Least One Planet

Do you wonder how astronomers find all those exoplanets orbiting stars in distant solar systems?

Mostly they use the transit method. When a planet travels in between its star and an observer, the light from the star dims. That’s called a transit. If astronomers watch a planet transit its star a few times, they can confirm its orbital period. They can also start to understand other things about the planet, like its mass and density.

The planet Mercury just transited the Sun, giving us all an up close look at transits.