Interesting Structures in the Cassiopeia Nebula from Web Notes | Urania

You can see interesting structures with very strange names invented by researchers, for example “Green Monster” and “Baby Cas A” in the latest snapshots of the Cassiopeia A (Cas A) nebula from the Webb telescope.
Cas A is the remnant of a supernova explosion about 340 years ago in our galaxy at a distance of about 11,000 light-years. from Earth.

The illustration in the title shows the remnants of a supernova explosion Kasgubeja A The following interesting structures are highlighted in the near infrared (they can also be seen under magnification in the numbered figures on the right):
(1) According to astronomers, the distinct portion of the Cas A nebula shows how the star appears to “shatter” like glass after a supernova explosion. The exceptional resolution of NIRCam images allows you to see small nodes of gas containing sulfur, oxygen, argon and neon coming from the star – the predecessor of the supernova. Some filaments are so narrow that they cannot be resolved even by the Webb telescope – which means that their size is only 100 AU (~14 light hours – for comparison, the most distant “products” of our civilization from Earth Sundae Voyager 1 and Voyager 2 Currently farther away, at distances of 162 AU / 135 AU, or 22.5 / 19 light hours).
(2) Astronomers believe that in this region the remnants of a supernova explosion collide with material that was ejected before the explosion. The circular holes visible in the MIRI image in the “Green Monster” region, i.e. the green ring in Cas A's inner void, are subtly highlighted by white and purple emissions in the NIRCam image, which represent ionized gas.
(3) One of several Cas A light echoes observed by NIRCam. Optical echoes arise when electromagnetic radiation, for example after a supernova explosion, collides with a distant surface (for example, a dust cloud) in its path and is reflected from it, reaching the observer with a delay resulting from the geometry of the phenomenon.
(4) A particularly large, complex light echo was captured by NIRCam, which the researchers named “Baby Cas A.” In fact, the source of this echo is located at a distance of about 170 litres. Left behind the Cas A supernova explosion.

The hidden “green monster” and synchrotron radiation

Near- and mid-infrared images captured by the James Webb Telescope (NIRCam vs MIRI) show a striking change in the appearance of the main part of Cas A's inner shell. Both images can be imaged Compare carefully by moving the slider left and right on the appropriate ESA page. The NIRCam image shows what appear to be plumes of smoke in the outer region of the envelope, where the supernova shock wave collides with the surrounding interstellar material. The white color in this image corresponds to synchrotron radiation, resulting from charged particles moving at extreme speeds around magnetic field lines.

The elusive mid-infrared “green monster” remains hidden in the NIRCam image – creating an additional aura of mystery around Cas A. Astronomers are very interested in understanding the nature of this intriguing structure.

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In the illustration: A set of images of the Cassiopeia A (Cas A) supernova explosion remnant from the Webb telescope (left – near-infrared shot from NIRCam, right – mid-infrared shot from MIRI instrument).
The Cas A image from NIRCam has a higher resolution (and is sharper) than MIRI, which results from observations in a shorter wavelength range.
The outer regions of the main Cas A inner shell visible in orange and red in the MIRI image correspond to the smoke plumes in the NIRCam image. This transition marks where the supernova's shock wave collides with the surrounding interstellar material. The dust in this material is too cold to be observed in the near infrared (=NIRCam), but becomes bright in the middle infrared (=MIRI).
The green ring in Cas A's central void, which astrophysicists have dubbed the “Green Monster,” is not visible in the near infrared, but is visible in the mid-infrared.
source: NASA, ESA, CSA, STScI, D. Milisavljevic (Purdue University), T. Temim (Princeton University), I. De Looze (Ghent University)

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Pictured: The remnants of the Cassiopeia A (Cas A) supernova explosion, imaged in near-infrared light by the Webb Telescope's NIRCam. The direction in the sky is determined – the directions in the sky are NE (northeast), and the scale of the image is at a distance of 11,000. St. Where this supernova exploded and the colors were translated from infrared radiation invisible to humans to the known colors of the visible spectrum. source: NASA, ESA, CSA, STScI, D. Milisavljevic (Purdue University), T. Temim (Princeton University), I. De Looze (Ghent University)

Prepared by: Ryszard Pernikovich

more information:

Webb stuns NASA with a new, high-definition look at the exploding star
The Webb Telescope reveals the Cassiopeia supernova remnant in fine detail
Cas A (NIRCam and MIRI comparison)
Urania Gateway: Cassiopeia A – new images from JWST

Source: NASA, ESA, Canadian Space Agency, STScI,

Pictured: The remnants of the Cassiopeia A (Cas A) supernova explosion, imaged in near-infrared light by the Webb Telescope's NIRCam.
You can see (in Figure 1) small knots of gas containing sulfur, oxygen, argon and neon coming from the supernova's progenitor star.
Round holes appear in the MIRI image in the so-called “green monster” region. The “green monster” is subtly highlighted by white and purple emissions in the NIRCam image (see inset in Figure 2).
Figures 3 and 4 show examples of light echoes from this supernova explosion. source: NASA, ESA, CSA, STScI, D. Milisavljevic (Purdue University), T. Temim (Princeton University), I. De Looze (Ghent University)