After a very long wait of decades and a very successful deployment the James Webb Space
Telescope has delivered it’s first science in its mission that will last at least a decade.
The first images were beyond spectacular, and while they were in some ways intended
to kick the tires and show the telescope off, discoveries and mysteries were nonetheless
revealed in these initial images.
The first major discovery involves the Southern Ring Nebula, or NGC 3132.
This is known as a planetary Nebula.
When you look at this image, you are seeing the future of the sun and our solar system.
This somewhat mis-named type of nebula has nothing to do with planets per se, rather
in the early days of astronomy it was noted that these kinds of nebulae resembled planets
in early telescopes, but did not move like planets, and the name stuck.
What actually happens here is that at the end of a one to eight solar mass red giant
star’s life, it sheds its atmosphere and becomes ionized and essentially lit up.
This phase is short lived for a star, only a few tens of thousands of years, but we see
examples just because of the sheer amount of stars in the milky way, over 100 billion.
NGC 3132 lies at a distance of about 2500 light-years, and has been found by Webb to
actually have a double star system at its core.
It’s interesting because both stars are capable of producing planetary nebula, the
dimmer star is the one producing the currently seen nebula, and itself is at the white dwarf
stage of stellar evolution.
The other star in the system isn’t to that stage yet, it’s in an earlier stage, so
in the future long after the current nebula has dissipated a second shell of dust and
gas will form in this system and persist for a few thousand years, sort of like a delayed
second burst in a fireworks display.
Using JWST’s Mid-Infrared instrument and its Near Infrared Camera, characterization
of this nebula shows intricate patterns in the dust and gas that show the interplay of
the two closely orbiting stars.
If you could see this system from another angle, it would look something like this image,
but since we see it at a sort of sideways perspective for lack of a better term, we
see it as a planetary nebula.
You can actually reconstruct the recent history of this star system by the patterns in the
nebula, and how close they are from the pair of stars.
Other features are where light from the binary system forms strong rays flowing through gaps
in the gas and dust shell.
This overall allows astronomers to study stellar evolution in a late stage, and how planetary
nebulae like this enrich the interstellar medium with materials that could someday be
incorporated into new planets, perhaps even ones similar to earth, but also give insight
into what our solar system might be like during the late stages of the sun’s future red
giant phase.
Perhaps earth, if it survives, may one day lie within a planetary nebula like NGC 3132.
The next image is intended to be an eye popper.
This is the Carina Nebula, which can be called a stellar nursery.
This is where stars are typically born, gigantic nebulae like this spawn stars across the universe.
With the much higher resolution of James Webb over that of previous space telescopes, scientists
will be able to gain insight on star formation, especially studying the fine details of these
many light-years wide clouds of gas and dust.
Within the Carina Nebula there are very young hot stars forming gaseous cavities within
the nebula that ultimately determine the outer features that we see, known as cosmic cliffs,
allowing astronomers a kind of probe of the interior of the nebula, and the effect of
the hot ultraviolet light streaming off the stars helping to sculpt and even dissipate
the nebula itself.
Interestingly, this is something we really couldn’t do with Hubble.
But before we get to that, it’s interesting to compare the resolution of Hubble with the
much larger JWST.
The gain in resolution and light collection is quite clear.
But given that Webb is a predominantly infrared telescope, it can reveal things and probe
differently than visible light telescopes, gaining insight on objects that in visible
light are obscured by dust.
You can even see protostellar jets in this image, which stream out from young stars in
this situation.
This is also an evolutionary process.
Once you have a star inside a nebula like this, the motion of the dust and gas as a
result of the presence and radiation of the star can trigger further collapses in the
nebula to form even more stars.
Eventually though, so much material is blown out that star formation ceases.
Webb will provide significant insight into this process of evolution in great detail,
including potentially answering questions about how many stars form in a certain region
under these conditions, and what governs their masses.
As an aside, the carina nebula is home of one of the strangest stars we’ve seen in
the Milky Way.
It’s eta carinae, and it’s a ridiculously unstable and active supergiant star.
It’s at least a binary star system, there are at least two stars involved by maybe more,
that together are five million times more luminous than the sun.
This system has dramatically brightened in the past, flaring up in 1837 and 1843, only
to fade out of naked eye visibility a little over a decade later.
It flared again at the end of the 19th century, dimmed, and then began a sustained brightening
around 1940 that continues to this day.
This star is set to go supernova in the relatively near geologic future, and oddly enough emits
one of the few known natural laser beams in nature in ultraviolet from its position nestled
in the homunculus nebula, a shell of gas it emitted in the past, that forms a kind of
nebula within a nebula.
To show a wide range of observations, the next is of particular interest.
Webb has been able to make long term observations of an exoplanet, WASP-96b.
This was actually a surprise, this exoplanet, actually termed a hot saturn though it differs
very much from our gas giants, orbits a G type star just over a thousand light-years
away.
This planet was chosen because it presents easy observation, frequently passing in front
of its host star allowing for relatively rapid fire observations from which to get good spectra
on the order of one pass every 3.5 days, resulting webb being able to collect 280 individual
spectra in a relatively short time.
It also has a significantly more extended atmosphere, helping for easy observation.
Previously, this planet was shown to have a strong signature of sodium, which at the
time led to a model of a gas giant with no upper cloud deck.
Webb has shown this not to be the case, with a very strong clear detection of water vapor
in this exoplanet’s atmosphere, and a corresponding likelihood of both clouds and haze.
How these two observations reconcile remains to be seen.
It’s worth noting here that WASP 96b is a gas giant, and not a candidate for terrestrial
life we know it, but the detection of water vapor by Webb shows that it’s capable of
detecting atmospheric water profiles of exoplanets, and will help in characterizing future exoplanets
that may host biospheres.
How this process works is surprisingly simple.
Known as a transmission spectrum, you measure the host star’s light as it passes through
the atmosphere of the exoplanet during a transit.
The gases present in the exoplanet’s atmosphere then absorb wavelengths of light, giving telltale
chemical signatures, such as water vapor, in the spectrum.
The next image is of an interesting group of galaxies known as Stephan’s quintet.
This is a visual cluster of five galaxies, though only four of the visible galaxies are
actually close to each other and interacting.
These galaxies are currently performing a dance that will ultimate result in their merger
into an enormous resulting irregular galaxy.
Interestingly, in the space between the galaxies, where interactions are occurring, there is
a radio source.
Long unexplained, this radio source has turned out to be a shockwave moving through intergalactic
gas that’s bigger than a galaxy, caused ultimately by one of the members moving into
the center of the cluster at very high speed.
One final image, the first released, is a deep field image, repeating the now famous
Hubble Space telescope’s deep field image.
This one really shows off the work of Albert Einstein clearly with it’s very obvious
display of gravitational lensing, where the gravity of foreground objects bending the
light of the galaxies behind them distorting the image as we see it.
This particular image however is turning out to be rather mysterious in that there are
two features that are not yet readily explained.
The first comes in the form of odd dots that do not appear to be stars in the image.
These could be any number of things, even artifacts in the imaging, or extremely distant
or dim stars or galaxies.
The other is this rather odd gravitational lensing event that seems to present multiple
images, and can also be seen in the same image taken by Hubble years ago.
It’ll be interesting to find out what these objects are.
But it does go to show that Webb’s work is just beginning, but with such stunning
images and capability, we can expect not only many more discoveries to add to the ones it
accumulated at the first few weeks it could, but will also reveal new mysteries in abundance
about the universe, of which we still know very little.
It’s going to be an interesting run for JWST indeed but there is one other notable
incident regarding this telescope.
While its launch, deployment, calibration and mission commencement went effectively
flawlessly, JWST did have one hiccup so far that simply cannot be prevented.
While its designed to withstand micrometeroid impacts, it is in space after all, it managed
to get hit by a larger than normal one which caused minor damage to one of the mirrors.
But the damage was non-zero, NASA reported that they could measure a very tiny effect
from the mirror damage in the data, but also noted that even after the impact the telescope
was still exceeding its design parameters and the mission is in no danger.
Hopefully that doesn’t happen too often from here on out.
And there you have it, an update on the first science released by the JWST team, and stunning
it is.
I look forward to many future updates about the discoveries the telescope makes, and new
mysteries of the universe, here we come.
Thanks for listening!
I am futurist and science fiction author John Michael Godier currently concerned about the
well-being of JWST.
Back in the day, I had a small rock put a non-zero chip in the LeBaron’s windshield
and while it didn’t affect anything, it does go to show that the universe just doesn’t
let us have nice things and be sure to check out my books at your favorite online book
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weird and unknown aspects of this amazing universe in which we live.