Skip to main content

This instrument weighs exoplanets by observing their gravitational effects

Photograph of the NEID instrument
The NEID instrument mounted on the 3.5-meter WIYN telescope at the Kitt Peak National Observatory. The NASA-NSF Exoplanet Observational Research (NN-EXPLORE) partnership funds NEID (short for NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy). NSF's National Optical-Infrared Astronomy Research Laboratory/KPNO/NSF/AURA

Researchers have shown the first results from a new instrument for calculating the weight of distant exoplanets. The NN-EXPLORE Exoplanet Investigations with Doppler spectroscopy, or NEID, is an instrument mounted on the WIYN telescope at the Kitt Peak National Observatory and is funded by NASA and the National Science Foundation.

Tools like the planet-hunting TESS telescope work by looking at the light coming from stars and seeing if there are periodic dips in light levels. If there are, this indicates a planet may be passing between the star and the Earth. If this dip happens on a fixed schedule, that suggests a planet in orbit.

Recommended Videos

The way NEID investigates distant planets is different: It looks for a tell-tale “wobble” of the stars around which the planets orbit. The same thing happens in our solar system — when a massive planet like Jupiter moves around the sun, its strong gravity causes the sun to move back and forth at roughly 43 feet per second (13 meters per second). The Earth produces this effect too, although as it is smaller and less massive, it only causes a wobble of 0.3 feet per second (0.1 meters per second). The larger the planet is in relation to the star, as well as the closer it is, the more wobble it causes.

NASA’s New Planet Tracker, NEID

Other instruments can detect wobbles of 3 feet (1 meter) per second, but NEID is more sensitive and can detect with three times the precision of these previous instruments. This means it can find rocky planets orbiting around smaller stars than our sun, as well as having a greater chance of locating smaller Earth-sized planets.

By observing stars’ wobbles, researchers can work out all sorts of information about orbiting planets, including their diameter, mass, and density. The density shows whether the planet is rocky or gaseous, and the distance from the star gives an indication of the surface temperature. Eventually, researchers may be able to locate Earth-like planets in orbit around sun-like stars at a distance which would allow liquid water to exist on their surfaces.

The “first light” image of NEID was shown off this week at the 235th meeting of the American Astronomical Society in Honolulu, illustrating the light detected from the sun-like star 51 Pegasi in the constellation of Pegasus.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Wild exoplanet has metal clouds and rain of liquid gems
Artist's impression of the exoplanet WASP-121 b. It belongs to the class of hot Jupiters. Due to its proximity to the central star, the planet's rotation is tidally locked to its orbit around it. As a result, one of WASP-121 b's hemispheres always faces the star, heating it to temperatures of up to 3000 degrees Celsius.The night side is always oriented towards cold space, which is why it is 1500 degrees Celsius cooler there.

In the pantheon of weird exoplanets, one of the strangest has to be WASP-121 b. It's so close to its star that not only is its surface temperature estimated to be up to an unimaginable 4,600 degrees Fahrenheit, but gravitational forces are pulling the planet apart and shaping it like a football. Now, new research reveals what the weather might be like on this hellish planet, and it's just as weird as you might think.

Located 855 light-years away, the planet is a type called a hot Jupiter because it's comparable in mass to Jupiter, at 1.2 times its mass, but its diameter is nearly twice as large. One reason that the planet has such extreme conditions is that it's close to its star that it is tidally locked, meaning one side of the planet called the dayside always faces the star and has the hottest temperature, while the cooler side called the nightside always faces away from the star into space.

Read more
NASA’s Swift Observatory is back to observing gamma-ray bursts
An artist's rendering of the Swift spacecraft with a gamma-ray burst going off in the background.

NASA's Swift Observatory, which investigates high-energy phenomena like gamma-ray bursts, has returned to operations following an issue which forced it into safe mode last month.

"NASA's Neil Gehrels Swift Observatory successfully returned to science operations Thursday, Feb. 17," NASA wrote in a brief statement. "The spacecraft and its three instruments are healthy and operating as expected."

Read more
Peering into the atmosphere of an ultra-hot exoplanet
Artist’s impression of WASP-189b, an exoplanet orbiting the star HD 133112 which is one of the hottest stars known to have a planetary system.

Of the over 4,000 exoplanets discovered so far, one of the strangest has to be WASP-189b. This ultra-hot Jupiter orbits so close to its star that its surface temperature could be up to 3,200 degrees Celsius, which is hot enough for iron to evaporate. Now, astronomers using the CHEOPS space telescope have investigated WASP-189b's atmosphere and found that it's just as odd as the planet beneath.

It's not easy to investigate the atmosphere of an exoplanet, but in this case, the researchers were able to look at the light coming from the extremely hot nearby star. “We measured the light coming from the planet’s host star and passing through the planet’s atmosphere," lead author of the study, Bibiana Prinoth, explained in a statement. "The gases in its atmosphere absorb some of the starlight, similar to Ozone absorbing some of the sunlight in Earth’s atmosphere, and thereby leave their characteristic ‘fingerprint’. With the help of [the HARPS spectrograph], we were able to identify the corresponding substances.”

Read more