JWST | Cartwheel Galaxy

The James Webb Space Telescope provided the most detailed look to date of the Cartwheel Galaxy with the image release on 2 Aug 2022. The galaxy was first observed by the U.K. Schmidt telescope and then by the Anglo-Australian Telescope. It lies about 500 mega lt-yrs from us in the constellation of Sculptor. A much larger and high resolution image is available for you at this link. When there, scroll down and look for Download Options. I will use the detailed image to point out some highlights farther down in this post.

JWST | August 2022
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Astro-Image | NGC 4845

I enjoy making color composites from three grayscale images using the technique in this post. The colors assigned are not necessarily what the human eye would see, but are used to bring out details in structure and composition. Gallery of previous Astro-Images.

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NGC 4845

This spiral galaxy is located in the constellation Virgo about 65 million light years away. Seen nearly edge-on, the bright core and the surrounding dust clouds are visible. The blue areas are artifacts of the original Hubble images used to make this composite.

Astronomers can observe the wavelengths of light from the galaxy to the left and right of the core. Rotation of the galaxy causes Doppler Shift of the wavelengths. The part of the galaxy moving away causes the wavelengths to be longer than normal. The part moving toward us causes the wavelengths to be shorter. The amount of shift in wavelengths indicates speed of rotation. A very massive central core of a galaxy results in fast rotation speeds.

Measurements of this galaxy allow astronomers to conclude a Black Hole resides in the core with a mass about 300,000 times the mass of our Sun. The galaxy was originally discovered by William Herschel in 1786.

Astro-Images | Centaurus-A

Centaurus-A is located in the southern hemisphere skies.  I have never seen it from my location 42˚ north latitude. It rises only 5˚ above my southern horizon in early December. I’m certain it is very familiar to my blogger friend Roger in Australia.  It is the 5th brightest galaxy and easily viewed by amateurs. It contains a black hole of 55 million solar masses ejecting jets of x-ray and radio wavelengths. Models suggest the galaxy collided with another smaller galaxy in the past leading to areas of star formation in the resulting complex structure. I enjoyed combining 3 greyscale Hubble images into this composite. In the center are several newly formed bluish stars. The dark areas are dust blocking the passage of light.

Centaurus-A | Hubble Legacy Archive | My Version

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M-87 Black Hole Details Revealed

Credit: Event Horizon Telescope Collaboration

Wednesday 10 April 2019 was a big day for the astronomy community. Information was presented from the Event Horizon Telescope (EHT) project revealing new details about the super-massive black hole in galaxy M-87. The intent of this post is to offer some perspective helpful to those who are not experts in this field.

Prior to the news release, I read a very comprehensive and helpful blog post by physicist Matt Strassler. His post addressed questions that were likely to be asked by the non-expert about the significance and details of the announcement. Some points he made were useful in the writing of this post.

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Astro-Images | Pillars of Creation

I’ve created color composites from three grayscale images using the technique in this post. The colors assigned are not necessarily what the human eye would see, but are used to bring out details. Unless otherwise noted, all images used three original grayscales from the Hubble Legacy Archive. Visit the gallery of previous Astro-Images.

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NGC 6611 From ESO

The Eagle Nebula is about 7000 lt yrs distant in the constellation Serpens of the southern skies. The cluster of bright stars at the core was discovered by Jean-Philippe de Chéseaux in 1745-46. Images today show much more detail than Chéseaux was able to see. This image made from 3 greyscale components by the European Southern Observatory in 2009 shows those details. The very bright open cluster of stars barely right of center causes gases to glow and silhouettes of the dust regions. Those bright young stars formed 1-2 million yrs ago.

ESO | European Southern Observatory

 

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