Fomalhaut: Look up in the pre-dawn in mid-June. Image from the Star Walk 2 App.
By Brooke Edwards
The James Webb Space Telescope (JWST) did it again. It has awed us once more, this time revealing a secret long hidden by a star. Fomalhaut, the 18th brightest star visible from Earth (not counting our Sun) and 25 light-years away, has been targeted in the search for worlds beyond our solar system.
There is a mysterious dust ring around the star that Hubble, Herschel Space Observatory and the ALMA telescope in Chile have focused on in the past, yet it was not until JWST captured the star system in infrared light that the secret was exposed. When the data was studied, the result shocked astronomers. What they discovered is not just the one, not two, but three belts around this star. Still, this left out an important piece of the puzzle ⸺ how and why they exist.
These discs of rock, dust and ice resemble the belts in our own solar system. The circular asteroid belt is just beyond the orbit of Jupiter, and the huge circular Kuiper belt of icy objects (including Pluto) is just beyond the orbit of Neptune. Simply stated, the Sun’s gravity keeps everything orbiting in place around it. All planets, belts and comets flow like traffic on solar highways circling our Sun.
Astronomers have not detected any so far, but there must be planets between Fomalhaut’s dust belts.
The current space telescope imagery is just not there yet, but astronomers can clearly see the patterns of a planetary system. Something is gravitationally directing the movement of Fomalhaut’s belts.
According to George Rieke, U.S. science lead for Webb’s Mid-Infrared Instrument (MIRI), “The belts around Fomalhaut are kind of a mystery novel: Where are the planets?”
These planets must be very tiny or may even be just forming. Who knows what will be discovered in time.
It is not known if NASA plans to use this method, but a sure way to detect planets is through the transiting method. This entails observing a celestial body (in this case, a planet) transiting ⸺ moving in front of⸺– its star. When this happens, the brightness of the observed star dims, signifying that a body has moved in front of it from our point of view.
You can see Fomalhaut, the star of this show, in the night sky. Starting in mid-June, those up before sunrise will be able to see Fomalhaut in the pre-dawn sky. It is the brightest star in the constellation Piscis Austrinus, which is known as the southern fish. Look toward the south-southeast after 5 a.m. to see this secret-harboring star with your own eyes.
Here’s to clear skies for us and amazing discoveries for the JWST team.
Brooke Edwards is a JPL/NASA Solar System Ambassador for the Manistee area. She is passionate about all things related to space exploration. Learn more about her summer star parties on Facebook @Brooke Edwards – Solar System Ambassador.
More stories by Brooke Edwards:
Step aside, Buzz Lightyear
Birth of a Blood Moon
How the dark skies of Manistee changed my life
Spectacular September Night Skies
NASA sets date for Artemis 1 moon launch
See our Astronomy & Space link in our Stories page for more.
