James Webb 2023: the telescope has photographed a star at the end of its life


James Webb 2023: the telescope has photographed a star at the end of its life

JAMES WEBB. A new photo taken by the James Webb Telescope has been released by NASA. This is the rare shot of a Wolf-Rayet type star in its last phase of life before it explodes into a supernova.

[Updated March 17, 2023 10:43 AM] On March 15, 2023, the James Webb Space Telescope unveiled the rare photograph of a star just before it went supernova. Named WR 124, the star is what is called "a Wolf-Rayet star". This is a phase of life experienced by some particularly massive stars before their explosion and death. With a mass 30 times that of our Sun, WR 124 is located in the constellation Sagittarius, 15,000 light-years from Earth. This star has been emitting gas and dust into space for tens of thousands of years.​​​​​​​

Captured in June 2022 when the telescope was just operational, this image again demonstrates the unique performance of James Webb. If the Hubble Space Telescope was able to photograph this star in 2015, its successor brings a new look at the star. Equipped with two instruments sensitive to infrared radiation, NIRCam and MIRI, James Webb is able to detect cosmic dust to which Hubble is insensitive. It thus reveals a breathtaking high-resolution photograph that could allow scientists to study the origins of the Universe and its history.

NASA unveiled Tuesday, March 14, 2023 the last snapshot of the James Webb Space Telescope on which we can see WR 124, a star of the Wolf-Rayet type. This type of star corresponds to a phase in the life of the star which precedes its explosion in the form of a spectacular supernova. For 20,000 years, WR 124 has passed through this stage of its existence and ejected its component layers in the form of plumes of gas and dust, thereby exposing its core. This phenomenon should last several hundred thousand years before ending with the death of the star.

Few stars pass through this stage, reserved for some of the most massive in the Universe, which is why this is a rare shot. We can admire the star in the center of the photo taken on June 22, 2022 as well as the halos formed by the gases and dust expelled by the star. The study of this dust makes it possible to better understand the origins of the Universe since these are the basis of the formation of the planets and stars that surround us.

In January 2023, the James Webb Space Telescope discovered its first exoplanet. In reality, it only confirmed a discovery made by the TESS satellite which has been scanning the celestial vault since 2018. Named LHS 475b, this world is only 41 light years away from us. It is a telluric planet like the Earth, of a size similar to that of the latter, but the comparison stops there. Indeed, this planet probably looks a lot more like Venus than Earth in many ways.

According to the results published by scientists from Johns Hopkins University, it is a planet that evolves very close to its star, a red dwarf. There is an average temperature of 460°C. Just like Venus, it could have an atmosphere extremely rich in carbon dioxide. But the data obtained do not yet allow us to conclude on the presence or total absence of an atmosphere around LHS 475b. The James Webb Telescope still has work to do and should make further measurements and observations to study this extraterrestrial world.

Using the James Webb Space Telescope, an international team of scientists studied a molecular cloud located in the constellation Chameleon. This molecular cloud is a nebula in which stars form. The team of scientists measured a temperature of -263°C in the center of this cloud. This temperature is only 10 degrees above absolute zero. According to the study published in the journal Nature Astronomy, this is the lowest ice temperature measurement that has been detected in a molecular cloud. In addition, thanks to its NIRCam camera, the space telescope was able to photograph the central zone of the cloud.

Molecular clouds are regions where there are hot and cold gases as well as dust and frozen particles. It is an active region that contains stars and protostars, ie stars in formation. Thanks to its instruments, the James Webb telescope was able to detect the presence of simple molecules such as ammonia or methane, but also complex molecules such as methanol. This type of cloud is interesting for astronomers because the dust it contains could eventually give rise to stars and potentially stellar systems. Researchers can therefore collect data that will allow them to better understand the role of chemical elements and ice present during the formation of planets and their atmospheres.

The James Webb Space Telescope is equipped with extremely powerful instruments that make it the most powerful space telescope ever designed. On November 16, 2022, a new image from the James Webb telescope reached us: it is a young star located in the constellation of Taurus. 100,000 years old and named L1527, the light it emits forms the shape of a blazing hourglass. The star is located in the center of the latter and we can see the presence of a rotating disk of gas which forms a horizontal bar partially masking the star.

The telescope was able to capture this image using its infrared camera, NIRCam, which perceives wavelengths invisible to the human eye. According to NASA and ESA, the European Space Agency, "this view of L1527 provides a window into what our early Sun and solar system looked like," reports France Info.

The Pillars of Creation, made famous by the iconic image taken by the Hubble Space Telescope, were also photographed by James Webb. The NIRCam camera that took the photo works in the infrared and allows you to see partially through the clouds of gas and dust. It is for this reason that many stars appear on this shot whereas they were not present on the famous Hubble photo.

It's been 30 years since the Voyager 2 spacecraft passed that we've had such a beautiful view of Neptune's rings. In September 2022, NASA transmitted an unpublished image of the planet Neptune on which the rings can be clearly distinguished as well as seven of the fourteen known moons of the planet.

Near Neptune we can thus see Galatea, Naiad, Thalassa, Despina, Proteus and Larisse. Farther away, but far brighter than the planet itself, is Triton, a moon covered in nitrogen ice that reflects sunlight extremely well.

On September 11, 2022, an exceptional image of the Orion Nebula taken by the most powerful telescope ever developed, James Webb, was unveiled to the world. According to a CNES press release, this "richest and closest stellar nursery in the Solar System" could "reveal information about the beginnings of our Solar System".

The Orion Nebula is located in the constellation of the same name, 1,350 light years from Earth. Its environment is similar to that in which our solar system was born more than 4.5 billion years ago. Admire the most detailed and sharpest image ever taken of the inner region of the Orion Nebula below:

On September 6, 2022, the telescope published a snapshot this time showing the Tarantula Nebula. This image is by far the most accurate of this nebula, revealing "details of its structure and composition, as well as dozens of galaxies in the background", comments NASA.

In July 2022, the James Webb Telescope transmitted among its first shots an image of the Carina Nebula. The image made it possible in particular to appreciate the unprecedented performance of the telescope since this nebula had already been photographed in the past by the Hubble telescope, whose pictures were less precise than those of James Webb.

In December 2022, NASA said it had discovered "buried treasure" in this shot. These are extremely young stars that scientists have spotted by carefully analyzing the photo. This discovery could help astronomers understand the processes that lead to the formation of a star like the Sun.

Early shots from the James Webb Telescope also included a photograph of the Southern Ring Nebula, located in the constellation Veils. It contains in its center two stars including a white dwarf which caused the formation of the nebula.

After several months of testing and calibrating the instruments of the James Webb Telescope, the long-awaited first snapshot of James Webb was revealed to the world on Monday, July 11, 2022 at 11 p.m. by US President Joe Biden. The image is spectacular and shows galaxies formed shortly after the Big Bang, more than 13 billion years ago... Since then, the James Webb Telescope continues to amaze us:

Hubble is an extremely powerful space telescope which has made it possible to discover a very large number of galaxies and to obtain completely new shots of many nebulae and other celestial objects. While it was only supposed to last ten years, Hubble continues, 30 years later, to send us spectacular images and improve our knowledge of the Universe. "One of Hubble's most enduring achievements is bringing the wonders of the universe to the general public," Kenneth Sembach, director of the Space Telescope Science Institute, told National Geographic magazine.

Since the 90s, technologies have greatly evolved and the modern design of James Webb makes it an instrument with even greater ambitions than those of its predecessor. While Hubble is in orbit around the Earth, James Webb was positioned 1.5 million kilometers from our planet. Thanks to this positioning and its state-of-the-art instruments, it gains in precision and can observe even older objects. It can also provide details on structures discovered by Hubble, such as the Carina Nebula photographed by Hubble and then by the James Webb Telescope.

From a technical point of view, the two space telescopes are without common measure. The James Webb Telescope is equipped with the largest mirror ever sent into space. With 6.5 meters in diameter, the latter is 3 times larger than that of Hubble. Its sun visor is also of unparalleled size, measuring 22 meters by 12, or 4 times the area of ​​Hubble's.

The name of the telescope was chosen to pay tribute to a NASA administrator, James Edwin Webb. He held office between 1961 and 1968 during the Apollo program of the American agency, which aimed to land a man on the Moon. His responsibility for the success of the program is widely accepted within NASA.