Tomorrow is the big day. After six months of waiting for the arrival of the James Webb Space Telescope at its destination, 1.5 million km away, the European (ESA), North American (NASA) and Canadian (CSA) space agencies will show the world the first scientific images of the most powerful space telescope built by man.
With only a few hours to go before the historic presentation, those responsible for the James Webb have made public the objectives chosen to show tomorrow in images that are expected to have unprecedented quality and detail.
This is the first batch of full-color scientific photographs and spectra collected by the observatory, and the official start of Webb’s science operations. The different targets were carefully selected by an international committee of representatives from the three agencies that manage the telescope, together with the Space Telescope Science Institute.
Among the objects, several have been selected that had already been photographed by the Hubble Space Telescope, so that we can appreciate the differences. Below we list the five objects whose images and spectra will be revealed tomorrow.
Carina Nebula
Also called Eta Carinae and cataloged as NGC 3372, it is one of the most colorful, complex and best studied areas by astronomers. Visible from the southern hemisphere and located in the Carina-Sagittarius Arm, the nebula is approximately 8,500 light-years from Earth. Four times larger than the Orion Nebula, in it the dark areas alternate with other very bright ones, due to the presence of numerous O-type stars, among the most massive, bright and hot in the galaxy, which are very difficult to study because of its turbulent environment, which blinds telescopes.
In Eta Carinae there are also several stars of the WR (Wolf-Rayet) type, among the hottest that exist. Among them, the spectacular WR 25, which is the most luminous and hottest star known in the Milky Way. The star Eta Carinae also stands out, between 100 and 150 times more massive than the Sun and four million times brighter.
A portion of the Carina Nebula is known as the Keyhole Nebula. It is much smaller and darker, with only seven light years in diameter, but it highlights the famous “defiant finger of Carina”, which seems to be doing a comb to the rest of the Universe.
Exoplanet WASP 96b
In this case, the James Webb will not show a photograph, but the spectrum of this planet, which is 1,150 light years from our Solar System. It is a gaseous world and its orbital period is 3.4 days. We know that it is about half the mass of Jupiter and was discovered in 2014. Spectrographic data from Webb will reveal the composition and characteristics of this distant planet in unprecedented detail.
Southern Rings Nebula
At 2,000 light-years away, it is one of the closest planetary nebulae to Earth. Planetary nebulae form when the star at their center is violently stripped of its outer layers, creating a bright ring that completely surrounds it. However, in this case the central stars (there are two) are surrounded by eight different rings, which is why it is also known as the Eight Bursts Nebula.
The images obtained by the Hubble Space Telescope clearly show that at the center of this object there is not one, but two stars, one brighter than the other, although the fainter one is responsible for the ejection of the material that shapes the nebula. . The new Webb images will make it possible to study this system in much more detail than ever before and to gain a better understanding of these peculiar cosmic objects.
Stephan’s Quintet
About 290 million light-years away in the constellation Pegasus, Stephan’s Quintet is the first compact group of galaxies ever discovered. In one of the most beautiful images taken by Hubble, its five members form the most well-studied compact group by astronomers. Four of the five galaxies that make it up have been executing a dance for millions of years in which they pass close to each other and exchange abundant material.
In the future, those four galaxies will eventually collide with each other and perhaps merge into a single, much larger galaxy. The powerful instruments of the James Webb Space Telescope will be able to observe this group with much more precision, and perhaps improve the already spectacular image obtained by its predecessor, the Hubble Space Telescope.
SMACS 0723 gravitational lens
Tomorrow’s fifth and final image will serve to better understand how exactly the phenomenon known as ‘gravitational lensing’ works, which allows astronomers to observe, as if they were much closer, objects that are actually at enormous distances.
We know that matter curves space, and that the more matter, the greater the curvature. Very massive galaxy clusters, then, have the ability to bend the paths of light reaching them from very distant objects that, from Earth’s perspective, are ‘behind’ them. That strong distortion acts, in effect, like a gigantic ‘cosmic magnifying glass’ that has the effect of enlarging these distant objects, often beyond the reach of ground-based telescopes.
All the images will be made public tomorrow, after a world presentation that will take place at 4:30 p.m. (Spanish time).