Massive stars are sprinters. It might seem counterintuitive that stars 100 or 200 times more massive than our Sun could only survive for as few as 10 million years. Especially since smaller stars like our Sun can last 10 billion years. Massive stars have huge reservoirs of hydrogen to burn through, but their massive size means fusion eats through their hydrogen much more quickly.
These massive stars are destined to reach the finish line quickly and explode as supernovae. There’s no other conclusion for them. But before they explode, some of them become Wolf-Rayet stars. That stage doesn’t last long, and the James Webb Space Telescope caught one in the act.
Hubble Space Telescope’s Deep Field revealed thousands of galaxies in a seemingly empty spot in the sky. Now, the James Webb Space Telescope has taken deep field observations to the next level with its COSMOS-Web survey, revealing 25,000 galaxies in just six pictures, the first from this new survey.
“It’s incredibly exciting to get the first data from the telescope for COSMOS-Web,” said principal investigator Jeyhan Kartaltepe, from the Rochester Institute of Technology’s School of Physics and Astronomy, in press release. “Everything worked beautifully and the data are even better than we expected. We’ve been working really hard to produce science quality images to use for our analysis and this is just a drop in the bucket of what’s to come.”
The NASA/European Space Agency (ESA)/Canadian Space Agency (CSA) James Webb Space Telescope (JWST) mission continues to dazzle and amaze with every image it beams back to Earth, and a recent observation depicting not one, not two, but three images of the same galaxy has been no different, as they proudly tweeted on February 28, 2023.
In the first data taken last summer with the Near Infrared Camera (NIRCam) on the new James Webb Space Telescope, astronomers found six galaxies from a time when the Universe was only 3% of its current age, just 500-700 million years after the Big Bang. While its incredible JWST saw these galaxies from so long ago, the data also pose a mystery.
These galaxies should be mere infants, but instead they resemble galaxies of today, containing 100 times more stellar mass than astronomers were expecting to see so soon after the beginning of the Universe. If confirmed, this finding calls into question the current thinking of galaxy formation and challenges most models of cosmology.
The Milky Way Galaxy contains an estimated one hundred billion stars. Between these lies the Interstellar Medium (ISM), a region permeated by gas and dust grains. This dust is largely composed of heavier elements, including silicate minerals, ice, carbon, and iron compounds. This dust plays a key role in the evolution of galaxies, facilitating the gravitational collapse of gas clouds to form new stars. This galactic dust is measurable by how it attenuates starlight from distant galaxies, causing it to shift from ultraviolet to far-infrared radiation.
However, the origin of various dust grains is still a mystery, especially during the early Universe when heavier elements are thought to have been scarce. Previously, scientists believed that elements like carbon took hundreds of millions of years to form and could not have existed before about 2.5 billion years after the Big Bang. Using data obtained by the JWST Advanced Deep Extragalactic Survey (JADES), an international team of astronomers and astrophysicists report the detection of carbonaceous grains around a galaxy that existed roughly 1 billion years after the Big Bang.
Astronomers have studied the star formation process for decades. As we get more and more capable telescopes, the intricate details of one of nature’s most fascinating processes become clearer. The earliest stages of star formation happen inside a dense veil of gas and dust that stymies our observations.
But the James Webb Space Telescope sees right through the veil in its images of nearby galaxies.
As the successor to the venerable Hubble Space Telescope, one of the main duties of the James Webb Space Telescope has been to take deep-field images of iconic cosmic objects and structures. The JWST’s next-generation instruments and improved resolution provide breathtakingly detailed images, allowing astronomers to learn more about the cosmos and the laws that govern it. The latest JWST deep-field is of a region of space known as Abell 7244 – aka. Pandora’s Cluster – where three galaxy clusters are in the process of coming together to form a megacluster.
While astronomers and engineers were trying to calibrate one of the James Webb Space Telescope’s instruments last summer, they serendipitously found a previously unknown small 100–200-meter (300-600 ft) asteroid in the main asteroid belt. Originally, the astronomers deemed the calibrations as a failed attempt because of technical glitches. But they noticed the asteroid while going through their data from the Mid-InfraRed Instrument (MIRI), and ended up finding what is likely the smallest object observed to date by JWST. It is also one of the smallest objects ever detected in our Solar System’s main belt of asteroids.
“We — completely unexpectedly — detected a small asteroid in publicly available MIRI calibration observations,” explained Thomas Müller, an astronomer at the Max Planck Institute for Extraterrestrial Physics in Germany, in a press release. “The measurements are some of the first MIRI measurements targeting the ecliptic plane and our work suggests that many, new objects will be detected with this instrument.”
It is an exciting time for astronomers and cosmologists. Since the James Webb Space Telescope (JWST), astronomers have been treated to the most vivid and detailed images of the Universe ever taken. Webb‘s powerful infrared imagers, spectrometers, and coronographs will allow for even more in the near future, including everything from surveys of the early Universe to direct imaging studies of exoplanets. Moreover, several next-generation telescopes will become operational in the coming years with 30-meter (~98.5 feet) primary mirrors, adaptive optics, spectrometers, and coronographs.
Even with these impressive instruments, astronomers and cosmologists look forward to an era when even more sophisticated and powerful telescopes are available. For example, Zachary Cordero of the Massachusetts Institute of Technology (MIT) recently proposed a telescope with a 100-meter (328-foot) primary mirror that would be autonomously constructed in space and bent into shape by electrostatic actuators. His proposal was one of several concepts selected this year by the NASA Innovative Advanced Concepts (NIAC) program for Phase I development.
Staring off into the ancient past with a $10 billion space telescope, hoping to find extraordinarily faint signals from the earliest galaxies, might seem like a forlorn task. But it’s only forlorn if we don’t find any. Now that the James Webb Space Telescope has found those signals, the exercise has moved from forlorn to hopeful.