Image (Credit): JWST’s view of the Milky Way. (NASA)
With the Thanksgiving holiday almost over, you may be thinking of Christmas lights after seeing the image above. Think larger, such as the size of a galaxy. You are looking at approximately 500,000 stars at the center of the Milky Way galaxy as seen by the James Webb Space Telescope (JWST), and it is pretty amazing.
The Webb telescope site has this to say about the image (and even more to say at the linked site):
A bright field of gas sweeps around the edge of a dark, dense cloud where young stars are bursting out to take their place in the universe. They join an estimated 500,000 other stars in the scene, of various ages, sizes, and colors. It’s the hub of our Milky Way galaxy, a city center at rush hour, making our solar system’s calm corner a frontier outpost by comparison. Discover the new features – and mysteries – NASA’s James Webb Space Telescope has revealed with its unprecedented infrared-light view of the chaotic region, and what it means for astronomy.
Image (Credit): Galaxy cluster MACS0416. (NASA, ESA, CSA, STScI, J. Diego (Instituto de Física de Cantabria, Spain), J. D’Silva (U. Western Australia), A. Koekemoer (STScI), J. Summers & R. Windhorst (ASU), and H. Yan (U. Missouri))
This week’s image combines the talents of the Hubble Space Telescope and the James Webb Space Telescope to create a dazzling show of light. The galaxy cluster, known as MACS0416, is about 4.3 billion light-years from Earth.
The image reveals a wealth of details that are only possible by combining the power of both space telescopes. It includes a bounty of galaxies outside the cluster and a sprinkling of sources that vary over time, likely due to gravitational lensing — the distortion and amplification of light from distant background sources.
This cluster was the first of a set of unprecedented, super-deep views of the Universe from an ambitious, collaborative Hubble programme called the Frontier Fields, inaugurated in 2014. Hubble pioneered the search for some of the intrinsically faintest and youngest galaxies ever detected. Webb’s infrared view significantly bolsters this deep look by going even farther into the early Universe with its infrared vision.
To make the image, in general the shortest wavelengths of light were colour-coded blue, the longest wavelengths red, and intermediate wavelengths green. The broad range of wavelengths, from 0.4 to 5 microns, yields a particularly vivid landscape of galaxies.
Those colours give clues to galaxy distances: the bluest galaxies are relatively nearby and often show intense star formation, as best detected by Hubble, while the redder galaxies tend to be more distant and are best detected by Webb. Some galaxies also appear very red because they contain copious amounts of cosmic dust that tends to absorb bluer colours of starlight.
While the new Webb observations contribute to this aesthetic view, they were taken for a specific scientific purpose. The research team combined their three epochs of observations, each taken weeks apart, with a fourth epoch from the CANUCS (CAnadian NIRISS Unbiased Cluster Survey) research team. The goal was to search for objects varying in observed brightness over time, known as transients.
They identified 14 such transients across the field of view. Twelve of them were located in three galaxies that are highly magnified by gravitational lensing, and they are likely to be individual stars or multiple-star systems that are briefly very highly magnified. The remaining two transients are within more moderately magnified background galaxies and are likely to be supernovae.
The finding of so many transients with observations spanning a relatively short timeframe suggests that astronomers could find many more transients in this cluster and others like it through regular monitoring with Webb.
Among the transients the team identified, one stood out in particular. Located in a galaxy that existed about 3 billion years after the Big Bang, it is magnified by a factor of at least 4000. The team nicknamed the star system Mothra in a nod to its ‘monster nature’, being both extremely bright and extremely magnified. It joins another lensed star that the researchers previously identified and that they nicknamed Godzilla. Both Godzilla and Mothra are giant monsters known as kaiju in Japanese cinema.
Interestingly, Mothra is also visible in the Hubble observations that were taken nine years earlier. This is unusual, because a very specific alignment between the foreground galaxy cluster and the background star is needed to magnify a star so greatly. The mutual motions of the star and the cluster should have eventually eliminated that alignment.
The most likely explanation is that there is an additional object within the foreground cluster that is adding more magnification. The team was able to constrain its mass to be between 10 000 and 1 million times the mass of our Sun. The exact nature of this ‘milli-lens’, however, remains unknown. It is possible that the object is a globular star cluster that’s too faint for Webb to observe directly.
If you are trying to learn more about the space programs at NASA, you can download the recently updated NASA+ app, which has a variety of videos and astronomy series to please anyone’s curiosity. For instance, check out the videos under “Scientific Wonders” to learn more about the James Webb Space Telescope, the New Horizons mission to Pluto, the Hubble Space Telescope, the Kepler Space Telescope, the OSIRIS-REx asteroid sample return, and much more.
This free app can bring you up to speed on the earlier space programs as well as provide updates on the latest missions. For example, you can watch the video showing yesterday’s docking of the SpaceX CRS-29 Cargo Dragon Resupply Craft with the International Space Program.
You cannot go wrong with this free app. You can read more about the updated NASA+ app here.
Image (Credit): The Ring Nebula as captured by the JWST. (ESA/Webb, NASA, CSA, M. Barlow (University College London), N. Cox (ACRI-ST), R. Wesson (Cardiff University))
This week’s image comes from the Jame Webb Space Telescope’s (JWST) Near-Infrared Camera (NIRCam). It shows the Ring Nebula, which is approximately 2,500 light-years away. It looks like a heavenly eyeball. with an Earth-colored iris.
Here is more on the image from NASA:
The NASA/ESA/CSA James Webb Space Telescope has observed the well-known Ring Nebula with unprecedented detail. Formed by a star throwing off its outer layers as it runs out of fuel, the Ring Nebula is an archetypal planetary nebula. Also known as M57 and NGC 6720, it is both relatively close to Earth at roughly 2,500 light-years away. This new image provides unprecedented spatial resolution and spectral sensitivity. For example, the intricate details of the filament structure of the inner ring are particularly visible in this dataset. There are some 20,000 dense globules in the nebula, which are rich in molecular hydrogen. In contrast, the inner region shows very hot gas. The main shell contains a thin ring of enhanced emission fromcarbon-based molecules known as polycyclic aromatic hydrocarbons (PAHs). Roughly ten concentric arcs are located just beyond the outer edge of the main ring. The arcs are thought to originate from the interaction of the central star with a low-mass companion orbiting at a distance comparable to that between the Earth and the dwarf planet Pluto. In this way, nebulae like the Ring Nebula reveal a kind of astronomical archaeology, as astronomers study the nebula to learn about the star that created it.
Image (Credit): Image of Jupiter taken by the Hubble Space Telescope. (Amy A. Simon/NASA/European Space Agency)
“We find them down as small as one Jupiter mass, even half a Jupiter mass, floating freely, not attached to a star…Physics says you can’t even make objects that small. We wanted to see, can we break physics? And I think we have, which is good.”
–Statement by Mark McCaughrean, a senior adviser for science and exploration at the European Space Agency, regarding Jupiter Mass Binary Objects (JuMBO). These objects were spotted by the James Webb Space Telescope in the Orion Nebula. They may be a new astronomical body as they do not fit into the normal star or planet category.
Our Awesome Universe 