TESS has Resumed Normal Operations

An artist’s rendition of the Transiting Exoplanet Survey Satellite (TESS). Credit: NASA's Goddard Space Flight Center

In April 2018, NASA launched the Transiting Exoplanet Survey Satellite (TESS), the successor to the Kepler Space Telescope that revolutionized the exoplanet studies field. Like its predecessor, TESS has been scanning almost the entire sky for five years for extrasolar planets using the Transit Method. This consists of monitoring thousands of stars for periodic dips in brightness, which may indicate a planet passing in front of the star relative to the observer. To date, TESS has made 243 confirmed discoveries, with another 4562 candidates – or TESS Objects of Interest (TOI) – awaiting confirmation.

On Monday, October 10th, fans of the TESS mission and the research it conducts got a bit of a scare as the observatory experienced a malfunction and had to be put into safe mode. Three days later, at around 06:30 PM EDT (03:30 PM PDT) on October 13th, NASA announced that their engineers had successfully powered up the instrument and brought it back online. While technicians at NASA are still investigating the cause of the malfunction, the spacecraft is now back in its fine-pointing mode and has resumed its second extended mission (EM2).

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TESS Finds a Super-Earth and two Mini-Neptunes in a Single System

An artist’s rendition of the Transiting Exoplanet Survey Satellite (TESS). Credit: NASA's Goddard Space Flight Center

The field of extrasolar planet studies continues to grow by leaps and bounds. Currently, 5,090 exoplanets have been confirmed in 3,816 systems, and another 8,933 candidates are awaiting confirmation. The majority of these have been Neptune-like gas giants (1,779), gas giants comparable to Jupiter or Saturn (1,536), and rocky planets many times the size of Earth (1,582). The most effective means for finding exoplanets has been the Transit Method (aka. Transit Photometry), where periodic dips in a star’s brightness are seen as an indication of a planet passing in front of its star (transiting) relative to the observer.

Using data from NASA’s Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers has discovered a three-planet system orbiting a Sun-like star (HD 22946, or TOI 11) located about 205.5 light-years. Based on size estimates yielded from their transits, the team theorizes that these exoplanets consist of a rocky planet several times the size of Earth (a Super-Earth) and two gas giants smaller than Neptune. Given its proximity, this system could be ideal for follow-up studies and characterization with the James Webb Space Telescope (JWST).

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Not Just a Planet Hunter. TESS Found Over 25,000 Flaring Stars

One of the beauties of modern-day space telescopes is that the data they produce, which is eventually wholly released to the public, contains useful information about much more than their primary mission objective. Other astronomers can then sift through the data using their own ideas, and in many cases, their own algorithms. Recently, a team from Poland turned a flare-searching algorithm on TESS’s planet-hunting data, and found an astonishing 25,229 stars with solar flares in the data set.

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Two New Rocky Planets Discovered Close to the Solar System

An artist's illustration of two newly-discovered super-Earths. They're only 33 light years away and they orbit a red dwarf named HD 260655. Image Credit: NASA/JPL-Caltech

TESS has struck paydirt again. NASA’s planet-hunting spacecraft has found two new super-Earths orbiting a star only 33 light-years away. These are two of the closest rocky planets ever found.

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TESS Finds Almost 100 Quadruple Star Systems

This is an artist's illustration of the quadruple star system 30 Arietis. Astronomers are discovering more quadruple star systems as observational power increases. Image Credit: Karen Teramura, UH IfA

NASA’s Transiting Exoplanet Survey Satellite (TESS) has found over 5000 candidate exoplanet candidates, and 197 confirmed exoplanets since its mission began in late 2018. TESS is good at finding exoplanets, but the spacecraft is a powerful scientific platform, and it’s made other discoveries, too. Scientists working with TESS recently announced 97 quadruple star candidates, nearly doubling the number of known quadruple systems.

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It Turns out, We Have a Very Well-Behaved Star

Our Sun is a Population II star about 5 billion years old. It contains elements heavier than hydrogen and helium, including oxygen, carbon, neon, and iron, though only in tiny percentags. Image: NASA/Solar Dynamics Observatory.
Our Sun is a Population II star about 5 billion years old. It contains elements heavier than hydrogen and helium, including oxygen, carbon, neon, and iron, though only in tiny percentags. Image: NASA/Solar Dynamics Observatory.

Should we thank our well-behaved Sun for our comfy home on Earth?

Some stars behave poorly. They’re unruly and emit powerful stellar flares that can devastate life on any planets within range of those flares. New research into stellar flares on other stars makes our Sun seem downright quiescent.

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5,000 Exoplanets!

An artist's illustration of NASA's TESS with Earth and the Moon. Image Credit: NASA

Before NASA’s TESS (Transiting Exoplanet Survey Satellite) mission launched in 2018, astronomers tried to understand what it would find in advance. One study calculated that TESS would find between 4430 and 4660 new exoplanets during its primary two-year-long mission.

The primary mission (PM) is over, and TESS is in its extended mission (EM) now. The extended mission is 1.5 years old, and TESS has discovered 176 confirmed exoplanets and 5164 candidates. Scientists are still going through data from the primary mission, so the data might be hiding many more exoplanets. And TESS isn’t finished yet.

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These Newly-Discovered Planets are Doomed

An artist’s rendition of what a planetary system similar to TOI-2337b, TOI-4329b, and TOI-2669b might look like, where a hot Jupiter-like exoplanet orbits an evolved, dying star. Image Credit: Karen Teramura/University of Hawai?i Institute for Astronomy

Astronomers have spied three more exoplanets. But the discovery might not last long. Each planet is in a separate solar system, and each orbits perilously close to its star. Even worse, all of the stars are dying.

The results?

Three doomed planets.

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Exoplanet Found With a Highly Eccentric Orbit

An artist's rendering of TOI-1231 b, a Neptune-like planet about 90 light years away from Earth. Credit: NASA/JPL-Caltech

The study of extrasolar planets has revealed some interesting things in recent decades. Not only have astronomers discovered entirely new types of planets – Super Jupiters, Hot Jupiters, Super-Earths, Mini-Neptunes, etc. – it has also revealed new things about solar system architecture and planetary dynamics. For example, astronomers have seen multiple systems of planets where the orbits of the planets did not conform to our Solar System.

According to a new study led by the University of Bern, an international team of researchers recently observed a Mini-Neptune (TOI-2257 b) orbiting a red dwarf star located about 188.5 light-years from Earth. What was interesting about this find was how the small ice giant had such an eccentric orbit, which is almost twice as long as it is wide! This is almost two and a half times as eccentric as Mercury, making TOI-2257 b the most eccentric planet ever discovered!

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TESS Finds a New Mars-Sized Planet (With the Density of Mercury)

An artist's illustration of a hypothetical exoplanet orbiting a red dwarf. Image Credit: NASA/ESA/G. Bacon (STScI)
An artist's illustration of a hypothetical exoplanet orbiting a red dwarf. Image Credit: NASA/ESA/G. Bacon (STScI)

Some planets orbit their stars so closely that they have extremely high surface temperatures and extremely rapid orbits. Most of the ones astronomers have found are Hot Jupiters— planets in the size range of Jupiter and with similar compositions as Jupiter. Their size and proximity to their star make them easier to spot using the transit method.

But there’s another type of planet that also orbits very close to their stars and has extremely high surface temperatures. They’re small, rocky, and they orbit their star in less than 24 hours. They’re called ultra-short-period (USP) planets and TESS found one that orbits its star in only eight hours.

And the planet’s density is almost equivalent to pure iron.

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