There’s a new star you can wish upon called “MACS J1149+2223 Lensed Star 1,” or as astronomers are calling it, “Icarus” for short. Icarus is the latest discovery by the Hubble Space Telescope and it is over 100 times farther away than any star ever seen clearly as an individual rather than as part of a galaxy mass.
Scientists calculate that the observed light from Icarus was emitted when the universe was only 4.4 billion years old and traveled nine billion years to be observed today.
NASA and ESA (European Space Agency) published their findings on Monday, April 2 in the journal Nature Astronomy.
As a blue supergiant, Icarus was much bigger, brighter and hotter than our sun. Since blue supergiants do not have such a large lifespan, Icarus no longer exists, though its light has finally travelled nine billion years away to be viewed today with the Hubble Telescope. (It is possible that Icarus collapsed into a black hole or became a neutron star.)
To see Icarus, an effect called “gravitational lensing” was used, in which the mass of distant galaxies creates a magnifying glass-like effect. Gravitational lensing involves Einstein’s theory of general relativity which says in part, “mass bends light.”
In this case, the gravitational lensing was caused by the galaxy cluster MACS J1149+2223, which is estimated at five billion light-years from Earth.
The more massive an object, the more its gravitational field extends into space, thereby causing light passing near that object to bend and be refocused in another direction. The galaxy cluster and objects in the cluster can act as natural lenses and amplify light coming from distant sources behind them that make the source of light visible. This allows astronomers and cosmologists to learn about the formation and evolution of stars from the earliest times in the universe. In this case, the light of Icarus was magnified 2,000 times.
In the 400-plus years since Galileo first used his telescope to see the heavens in 1610, we have learned information about our galaxy that mankind never knew. The ancients didn’t know about Saturn’s rings or Jupiter’s moons, or even that that cloudiness across the night sky wasn’t clouds but countless distant stars. As big a jump as the first telescope made on our understanding of our galaxy, Hubble has helped make an even greater jump in our understanding of the universe.
The Hubble Space Telescope was named after Dr. Edwin P. Hubble (1889-1953). Dr. Hubble’s work confirmed the idea of the “expanding” universe which the Big Bang theory was built upon.
Hubble was launched with the space shuttle Discovery in 1990. The telescope is 43.5 feet long, 14 feet in diameter and weighs around 24,000 pounds. Hubble data is credited by astronomers in more than 15,000 scientific papers and it has made more than 1.3 million observations since it began its mission.
As the first space-based optical telescope, Hubble is not affected by the haze from Earth’s atmosphere, so it can see into the universe farther and clearer than even the best mountaintop telescope on Earth. It’s estimated that Hubble has vision equal to a human being able to see fireflies in Tokyo from Washington D.C. Since 1990 it’s maintained its 340-mile altitude above the earth, and moving at approximately 17,000 miles an hour, it has traveled more than four billion miles.
In 2020, NASA plans to launch the James Webb Space Telescope (JWST) to orbit 930,000 miles beyond Earth, much farther than the Hubble’s orbit at about 353 miles above Earth. The Webb Telescope will be able to look in all directions for longer periods than Hubble. The two telescopes will get complimentary views of objects for a more complete picture of the universe.