Tag Archives: TESS

TESS finds exoplanet smaller than Earth

Worlds without end: TESS has now found an exoplanet somewhere between Mars and the Earth in size, and is part of a solar system with two other Earth-sized planets.

L 98-59b is around 80% Earth’s size and about 10% smaller than the previous record holder discovered by TESS. Its host star, L 98-59, is an M dwarf about one-third the mass of the Sun and lies about 35 light-years away in the southern constellation Volans. While L 98-59b is a record for TESS, even smaller planets have been discovered in data collected by NASA’s Kepler satellite, including Kepler-37b, which is only 20% larger than the Moon.

The two other worlds in the system, L 98-59c and L 98-59d, are respectively around 1.4 and 1.6 times Earth’s size. All three were discovered by TESS using transits, periodic dips in the star’s brightness caused when each planet passes in front of it.

None of these planets is considered in the habitable zone however. Instead, they experience solar energies comparable to Venus.

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Tess finds Earth-sized planet?

Scientists using the space telescope TESS think they may have found its first Earth-sized planet.

Its host star has about 80 percent of the mass of our Sun and is found about 53 light-years distant from Earth. HD 21749b has about 23 times Earth’s mass and a radius of about 2.7 times Earth’s. Its density indicates the planet has substantial atmosphere but is not rocky, so it could potentially help astronomers understand the composition and evolution of cooler sub-Neptune planet atmospheres.

Excitingly, the longer period sub-Neptune planet in this system is not alone. It has a sibling planet, HD 21749c, which takes about eight days to orbit the host star and is much smaller—similar in size to Earth. “Measuring the exact mass and composition of such a small planet will be challenging, but important for comparing HD 21749c to Earth,” said Wang. “Carnegie’s PFS team is continuing to collect data on this object with this goal in mind.”

In other words, they know almost nothing yet about the smaller exoplanet. They think it is similar in size to the Earth, but they don’t know its mass or composition.

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TESS spots first exoplanets plus supernovae and more

The Transiting Exoplanet Surveying Satellite (TESS) has successful spotted its first exoplanets.

NASA’s Transiting Exoplanet Survey Satellite (TESS) has found three confirmed exoplanets, or worlds beyond our solar system, in its first three months of observations.

The mission’s sensitive cameras also captured 100 short-lived changes — most of them likely stellar outbursts — in the same region of the sky. They include six supernova explosions whose brightening light was recorded by TESS even before the outbursts were discovered by ground-based telescopes.

These discoveries confirm that the spacecraft is operating exactly as designed. Now comes the herculean task of analyzing the gigantic amount of data it is pouring down to see what is hidden there.

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NASA officially retires Kepler

NASA today officially retired Kepler after nine years of operations.

After nine years in deep space collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth. Kepler leaves a legacy of more than 2,600 planet discoveries from outside our solar system, many of which could be promising places for life.

Exoplanet hunting however does not end here. Unlike Hubble, astronomers and NASA planned ahead for Kepler’s demise, and this year launched TESS to continue its work, in an even more sophisticated manner.

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TESS releases its first batch of exoplanet candidates

The science team for the U.S.’s exoplanet space telescope TESS this week released its first batch of exoplanet candidates.

TESS scientists released the list so that other astronomers could make an initial determination as to whether these candidates are planets. There are 73 objects in this first batch, including some planets previously known from ground-based searches, says George Ricker, the mission’s principal investigator at the Massachusetts Institute of Technology in Cambridge. Perhaps 5 to 20% of the objects on the list will turn out to be false alarms, he says. Others, if confirmed, will join the ranks of newly discovered exoplanets.

Researchers expect TESS to find as many as 10,000 large planets. But its main goal is to discover and measure the masses of at least 50 small worlds no more than four times the size of Earth.

Meanwhile, Kepler has resumed operations despite being almost out of fuel. The science team there is attempting to squeeze every last ounce of data it can before the spacecraft’s fuel runs out.

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Tess captures comet, variable stars, asteroids, and Martian light

During its testing period prior to beginning science operations this month, the exoplanet space telescope TESS spotted in one series of images a comet, a host of variable stars, some asteroids, and even the faint hint of some reflected light from Mars.

Over the course of these tests, TESS took images of C/2018 N1, a comet discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) satellite on June 29. The comet, located about 29 million miles (48 million kilometers) from Earth in the southern constellation Piscis Austrinus, is seen to move across the frame from right to left as it orbits the Sun. The comet’s tail, which consists of gases carried away from the comet by an outflow from the Sun called the solar wind, extends to the top of the frame and gradually pivots as the comet glides across the field of view.

In addition to the comet, the images reveal a treasure trove of other astronomical activity. The stars appear to shift between white and black as a result of image processing. The shift also highlights variable stars — which change brightness either as a result of pulsation, rapid rotation, or by eclipsing binary neighbors. Asteroids in our solar system appear as small white dots moving across the field of view. Towards the end of the video, one can see a faint broad arc of light moving across the middle section of the frame from left to right. This is stray light from Mars, which is located outside the frame. The images were taken when Mars was at its brightest near opposition, or its closest distance, to Earth.

The video that was compiled from these images is embedded below the fold.
» Read more

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Kepler on verge of death

The Kepler space telescope is now almost out of fuel, and scientists have ceased science observations to devote the telescope’s last days downloading its last 51 days of data.

The telescope lasted far longer than planned, and discovered thousands of exoplanets. Its archives will be producing new discoveries for decades. And a new exoplanet space telescope, TESS, is already in orbit to take over.

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TESS completes lunar flyby, takes first test image

The Transiting Exoplanet Survey Satellite (TESS) yesterday successfully completed its slingshot flyby of the Moon to place it in its final operational orbit.

The spacecraft also used one of its four cameras to successfully take a 2-second test exposure, proving that the camera and pointing system both work. The first science image is expected in June.

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SpaceX successfully launches NASA new exoplanet telescope

Capitalism in space: SpaceX today successfully placed NASA’s new explanet space telescope, TESS, into orbit.

The first stage, which was making its first flight, successfully landed on the drone ship in the Atlantic. They hope to reuse this booster on a future Dragon launch.

Update: TESS’s solar arrays have successfully deployed.

The leaders in the 2018 launch standings:

11 China
8 SpaceX
4 ULA
3 Japan
3 Russia
3 Europe
3 India

The U.S. is now ahead of China, 12 to 11, in the national list.

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Cameras on next Kepler-like exoplanet space telescope out of focus

NASA has revealed that the cameras on the Transiting Exoplanet Survey Satellite (TESS) become slightly out of focus when they are cooled to -75 Celsius, the temperature they will experience in space.

NASA has also decided that the fuzziness is not enough to require a fix, and is proceeding with the mission as is, despite concerns expressed by scientists.

Alan Boss, an astronomer with the Carnegie Institution, brought up the issue in a summary of a meeting last week of the Astrophysics Advisory Committee, of which he is a member. “That could have some big effects on the photometry,” he said of the focus problem. “This is certainly a concern for the folks who know a lot about photometry.”

TESS will use those cameras to monitor the brightness of the nearest and brightest stars in the sky, an approach similar to that used by Kepler, a spacecraft developed originally to monitor one specific region of the sky. Both spacecraft are designed to look for minute, periodic dips in brightness of those stars as planets pass in front of, or transit, them. Chou said that since TESS is designed to conduct photometry, measuring the brightness of the stars in its field of view, “resolution is less important compared to imaging missions like Hubble.” However, astronomers are concerned that there will be some loss of sensitivity because light from the stars will be spread out onto a slightly larger area of the detector.

“The question is how much science degradation will there be in the results,” Boss said. “The TESS team thinks there will be a 10 percent cut in terms of the number of planets that they expect to be able to detect.”

It could be that NASA has decided that the cost and delay required to fix this is not worth that 10% loss of data.

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