The Hubble Telescope is happily approaching the 32nd anniversary of its launch. On this occasion, the Telescope Institute treated us with an image of an unusual part of the universe, one of the densest galaxy formations in known space.
Time can be measured in several ways. For fans of astronomy, this could be, for example, the consecutive anniversary of the Hubble Space Telescope. This time we will not focus on the history of the telescope itself, because you probably already know it well. If not, check out last year’s text, which details the fate of the most famous cosmic observation tool.
The instruments in this telescope are at least twelve years old, and some, like the ACS camera, are 20 years old. Incredibly, Hubble is older than that StandardThis is one of the oldest Polish computer sites.
Hubble (the telescope, of course) remembers the days when computers were only related to business, and the fan joke of the Intel 80286 processors wasn’t widely known until now. When our service came onto the Internet scene in June 1997, Hubble had already completed two major operations, i.e. service tasks, to improve and/or replace worn out parts and tools. As well as a lot of groundbreaking discoveries.
32 years of Hubble covers a large part of our recent history
If Hubble could document our world from orbit, in his 32 years he would have seen the enormity of the changes that accompanied the rise of digital civilization. He will also see the mistakes made by man and their consequences that affect us in a very specific way.
The purpose of this telescope was completely different and is still different. Look at the stars, galaxies and sometimes planets too, look at the seemingly peaceful abyss in space. These are the most exciting images taken by Hubble. It shows cosmic events frozen in time as they occur farther away, the further you advance in them.
Each year, Hubble records interesting observations and discoveries. Not all of them happen exactly on the day the information is published, because in science you need to be at least a little confident before announcing anything.
One of the most interesting Hubble discoveries that we have learned recently is the discovery of the most distant galaxy, HD1. This galaxy is more of a speck than an object we identify with as a group of stars, so the discovery didn’t have a startling effect on our sense of sight. On the other hand, images of galaxies closest to us that have different shapes leave this impression.
Hickson Compact Group 40, in memory of the Hubble Telescope
And so, on its 32nd birthday, Hubble gave us an image of a group of five galaxies taken in November 2021, known to astronomers as Hickson Compact Group 40, or Hickson 40 for short.
In space, the term compressed object can have different meanings. Neutron stars with a size of kilometers are compressed, but a group of galaxies with a size of tens of thousands of light-years can also be compressed. Imagine that the five galaxies that make up the Hickson Group 40 occupy an area less than twice the diameter of the Milky Way.
It is clear that these galaxies are bound together by a strong gravitational force that will inevitably lead them (on the cosmic time scale) to merge to form a huge elliptical galaxy. This process can accelerate in about a billion years (for an observer on Earth).
One of the main topics that baffles observers of Hickson 40 and other groups of this type is the discussion of the mechanism that leads to such a clustering of galaxies. One of the theories presented on this occasion supposes the presence of a large amount of dark matter in which these galaxies orbiting around the center of mass of the entire system is engulfed.
The merger of galaxies in this system can be a very interesting phenomenon from the perspective of the evolution of cosmic structures. Observations indicate that each of the five galaxies likely has a supermassive black hole at its center. The prospect of merging two of these facilities seems interesting, not to mention the chance of five.
If there is a civilization, you will probably enjoy some amazing night sky views
Meanwhile, in a group of galaxies located 300 million light-years away, cut off from the rest of the universe, lying in the direction of the constellation Hydra, everything seems to be going in the ancient direction. Yes, after the time when the light was emitted towards the Earth, the appearance of the system may have changed dramatically, but the inhabitants of the planets in these galaxies can still enjoy an unusual view of the sky. Anyone who has had the opportunity to observe the southern sky on Earth knows how effective the Magellanic Clouds are in good weather.
However, it all depends on the location of the monitoring site in such a system. In a worst-case scenario, the inhabitants of one of these galaxies might not realize that they are in such an interesting place in space.
In the Southern Hemisphere, not only the galactic disk and the center of the Milky Way are fully visible, but also two satellite galaxies, the Large and Small Magellanic Clouds.
In the case of the Milky Way, the closest similar galaxy (actually larger) is the Andromeda galaxy, 2.5 million light-years away. Our galaxy contains many smaller satellite galaxies, but only the Large and Small Magellanic Clouds attract the human eye. The rest are dwarf galaxies that blend into the background of stars in our galaxy’s halo. Some of them are hard to notice (we probably haven’t discovered many yet) because they are obscured by the material of the galactic disk.
The three types of galaxies in Hickson Compact Group 40
The galaxies that make up Hickson 40 are of three types. We have three spiral galaxies, two of which are slightly tilted toward the direction of observation, and the third is seen roughly along the plane of the galactic disk. The lowest visible galaxy is the lenticular galaxy, an interface between spiral and elliptical galaxies. The elliptical galaxy, in turn, is the fifth galaxy visible in the image.
The image also shows many other galaxies, but they are located very far away and are not gravitationally related to the five galaxies listed above. There are also many stars in the Milky Way visible in the foreground.
Galaxies that are close to each other in the image do not necessarily have to be close to each other in reality
Hickson’s catalog contains 100 compressed groups of galaxies. Group No. 40 is one of the more compact formations, but the most famous, especially for fans of astronomy, is the so-called Stefan Quintet (No. 92 in the catalog). Interestingly, although we also see five closely spaced galaxies in the sky, only four of them are close to each other. The fifth, as the observations showed, is the protagonist of the foreground, which is 2 times closer to us than the other galaxies of Stefan Quintet.
Source: Hubble, inf. king
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