JWST’s First Images

Written and edited by Huei Sears & Macy Huston

Following a preview of the first JWST Deep Field yesterday, NASA released its first JWST images of four other targets today: the Carina Nebula, WASP-96b, the Southern Ring Nebula, and Stephan’s Quintet.

Carina Nebula

The Carina Nebula is a large (the largest!) diffuse nebula in the southern sky and is only ~8.500 light years away. It hosts a number of star-forming regions and bright stars, including the most luminous star in our galaxy, WR 25. Most famously, this nebula is known to host the Eta Carinae star system.  Due to its size and close location to Earth, Eta Car is the most massive star that we are able to study in great detail.  There are a number of other features in this nebula that are interesting, such as the Keyhole Nebula, a variety of open star clusters, and dust-gas pillars.  The Keyhole Nebula is an opaque molecular and dust cloud in the shape of a keyhole.  Nebulae such as this that are opaque to visible light are called “Dark Nebulae.” 

From ESA: Located in the Southern Hemisphere, NGC 3324 is at the northwest corner of the Carina Nebula (NGC 3372), home of the Keyhole Nebula and the active, outbursting star Eta Carinae. The entire Carina Nebula complex is located at a distance of roughly 7,200 light-years, and lies in the constellation Carina. This image is a composite of data taken with two of Hubble's science instruments. Data taken with the Advanced Camera for Surveys (ACS) in 2006 isolated light emitted by hydrogen. More recent data, taken in 2008 with the Wide Field Planetary Camera 2 (WFPC2), isolated light emitted by sulfur and oxygen gas. To create a color composite, the data from the sulfur filter are represented by red, from the oxygen filter by blue, and from the hydrogen filter by green.

Hubble image of the Carina Nebula, composite from ACS and WFPC2. (Image credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA))

top from NASA: This landscape of “mountains” and “valleys” speckled with glittering stars is actually the edge of a nearby, young, star-forming region called NGC 3324 in the Carina Nebula. Captured in infrared light by NASA’s new James Webb Space Telescope, this image reveals for the first time previously invisible areas of star birth. Credits: NASA, ESA, CSA, and STScI. bottom from NASA: A star field is speckled across the image. The stars are of many sizes. They range from small, faint points of light to larger, closer, brighter, and more fully resolved stars with 8-point diffraction spikes. The stars vary in color, the majority of which have a blue or orange hue. The upper-right portion of the image has wispy, translucent, cloud-like streaks rising from the nebula running along the bottom portion of the image. The cloudy formation shown across the bottom varies in density and ranges from translucent to opaque. The cloud-like structure of the nebula contains ridges, peaks, and valleys – an appearance very similar to a mountain range. Many of the larger stars shine brightly along the edges of the nebula’s cloud-like structure.

JWST images of the Carina Nebula, “Cosmic Cliffs.” Top: Near-Infrared Camera (NIRCam) image. Bottom: NIRCam and Mid-Infrared Instrument (MIRI) composite image. (Credit: NASA, ESA, CSA, and STScI)

WASP-96 b 

WASP-96b is a hot Jupiter residing about 1,150 light years from Earth. It is about half the mass of Jupiter, but it is so hot that it has inflated to 1.2 times Jupiter’s radius. The planet orbits its Sun-like host star every ~3.5 days. WASP-96b was first discovered in 2014 by the Wide Angle Search for Planets (WASP) via the transit method. As a highly inflated planet with an extended atmosphere, WASP-96b is a great candidate for atmospheric characterization. Astronomers use transmission spectroscopy to measure the transit depth of an exoplanet passing in front of its star at different wavelengths, in order to study the contents of the planet’s atmosphere.

Prior transmission spectroscopy of this planet with the Very Large Telescope measured a precise sodium abundance, finding an absorption feature consistent with clear, cloud-free skies. Further study may reveal additional abundances in the atmosphere, as well as metallicity. Understanding the composition of gas giant planets is an important step in determining how they form and evolve. JWST’s transmission spectroscopy will allow for deeper study of this and other planets’ atmosphere than ever before.

transmission spectrum of WASP-96b. The y-axis shows planet-to-star radius ratio as well as pressure scale height, and the x-axis shows wavelength from 0..3 to 0.9 microns. Circles with large error bars mark the data points, and a few different lines in the background show different model atmospheres. A clear peak in the spectrum is visible near 0.59 microns, marked as a sodium line. We see no peak at the lithium 0.67 micron line. Models show a peak at the potassium 0.77 micron line, but the data does not show any obvious strong peak here.

Transmission spectrum of WASP-96b from the Very Large Telescope. Circles show observed data, and lines trace model atmospheres. (Extended data figure 5 from Nikolov et al. 2018)

from NASA: Graphic titled “Hot Gas Giant Exoplanet WASP-96 b Atmosphere Composition, NIRISS Single-Object Slitless Spectroscopy.” The graphic shows the transmission spectrum of the hot gas giant exoplanet WASP-96 b captured using Webb's NIRISS Single-Object Slitless Spectroscopy with an illustration of the planet and its star in the background. The data points are plotted on a graph of amount of light blocked in parts per million versus wavelength of light in microns. A curvy blue line represents a best-fit model. Four prominent peaks visible in the data and model are labeled “water, H 2 O.”

JWST transmission spectrum of WASP-96b, showing atmospheric water vapor features as well as evidence for clouds and haze. (Credits: NASA, ESA, CSA, and STScI)

Southern Ring Nebula

The Southern Ring Nebula (also known as NGC 3132, the Eight-Burst Nebula, and Caldwell 74) is a planetary nebula about 2,000 light years from Earth. It was discovered by John Herschel in 1835 and has been studied extensively since. Planetary Nebulae aren’t actually related to planets; they form from the outer layers of stars that get shed at the end of their lives, leaving behind a white dwarf. The name stems from early observations of such objects, where astronomers noted their round, planet-like shape and apparent size on the sky.  At the center of the Southern Ring Nebula lies a binary star system, one member of which is the remnant white dwarf and the other, a less evolved star. JWST will measure atomic and molecular abundances in the ejected gas and the temperature structure of the region.

Hubble image of the Southern Ring Nebula. A bright star with diffraction spikes is seen in the middle of an oval-shaped nebula. An inner region of hot gas is shown in blue, and outer regions with cooler gas and more cloudy substructures is shown in reddish-brown,

Hubble Space Telescope image of the Southern Ring Nebula. Blue represents the hottest gas, in the inner region, and red is the cooler, outer edge gas. (Image credit: Hubble Heritage Team, STScI/AURA/NASA/ESA)

from NASA: Two cameras aboard Webb captured the latest image of this planetary nebula, cataloged as NGC 3132, and known informally as the Southern Ring Nebula. Credits: NASA, ESA, CSA, and STScI

JWST images of the Southern Ring Nebula. Left: NIRCam. Right: MIRI. The MIRI image reveals the second star in the binary system for the first time! This second star is the remnant white dwarf, shrouded in dust, which ejected all the hot gas making up the planetary nebula, and the brighter star is in an earlier stage of stellar evolution. We can also see some galaxies in the background of the nebula! (Image credit: NASA, ESA, CSA, and STScI)

Stephan’s Quintet

Stephan’s Quintet is a group of five (5) galaxies found in the constellation of Pegasus by Edouard M. Stephan in 1877.  This was also the first compact galaxy group ever discovered!  Starting on the top left (in the image below), this white/blue/purple galaxy, NGC 7320, is actually about 7 times closer to Earth than the other 4 galaxies!  Continuing clockwise, NGC 7319 is a barred spiral galaxy with blue and red star clusters.  In this image, blue represents optical light at 438 nm, and red represents a mixture of optical light at 657 nm (commonly called “H alpha”), and infrared light at 814 nm and 1.4 micrometers (I-band and near-IR, respectively).  Continuing around the image, the interacting galaxy pair of NGC 7318A and NGC 7318B is surrounded by blue and pink star clusters.  Finally, the elliptical galaxy on the bottom left is known as NGC 7317.

Hubble image of Stephan's Quintet, a visual grouping of five galaxies. Sparkling clusters of millions of young stars and starburst regions of fresh star birth grace the image. Sweeping tails of gas, dust and stars are being pulled from several of the galaxies due to gravitational interactions.

“Galactic wreckage in Stephan’s Quintet” This image of the quintet was taken with the Wide Field Camera 3 on HST and was released in 2009. It is made up of optical and infrared imaging. (Image credit: NASA, ESA and the Hubble SM4 ERO Team)

left image, from NASA: This image of Stephan’s Quintet, a visual grouping of five galaxies, is contains over 150 million pixels and is constructed from almost 1,000 separate image files. Sparkling clusters of millions of young stars and starburst regions of fresh star birth grace the image. Sweeping tails of gas, dust and stars are being pulled from several of the galaxies due to gravitational interactions. Most dramatically, Webb captures huge shock waves as one of the galaxies, NGC 7318B, smashes through the cluster. Credits: NASA, ESA, CSA, and STScI. right image, from NASA: Image of a group of four galaxies that appear close to each other in the sky: two in the middle, one toward the top, one to the upper left. In addition, there is a large bright patch toward the right. The galaxy at the top has a bright reddish core and is surrounded by swirls of blue and purple filaments that travel inward to its bright core, also highlighted by eight diffraction spikes. The galaxy on the left is a mass of purple gas surrounding a dim red core. The mass is made from small clumps, each slightly illuminated. The two galaxies in the middle have two bright, blue cores, surrounded by purple wisps. The bright patch to the right is made from clouds of blue and purple, strung together in filament-like bands. Surrounding the galaxies is a background peppered with red, blue, and purple dots, which are distant stars and galaxies.

JWST image of Stephan’s Quintet. Left: NIRCam and MIRI composite image. Right: MIRI image. (Image credit: NASA, ESA, CSA, and STScI)

The First JWST Deep Field

In addition to the full Deep Field image released yesterday, today spectra of some of the galaxies in the image were revealed. See our previous bite for more about Deep Fields!

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More images and details are available here, including detailed alt text descriptions! Also, check out John Christensen’s Webb Compare sliders to compare HST and JWST imaging.

Cover Image Credit: NASA, ESA, CSA, and STScI

About Macy Huston

I am a fifth year graduate student at Penn State University studying Astronomy & Astrophysics. My current projects focus on technosignatures, also referred to as the Search for Extraterrestrial Intelligence (SETI), and on microlensing searches for exoplanets.

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