Phantom galaxy by Andrey Klimkovsky

Galaxy M74 or NGC 628 is located in the constellation Pisces. Now astronomers know hundreds and thousands of galaxies within any constellation, but this galaxy is special.

First, not many galaxies can be seen with your own eyes. Of course, we have long been accustomed to the fact that the most powerful orbiting telescopes pierce the Universe for us — they send amazingly beautiful pictures to Earth, and is it necessary to try to see something on our own? This is a matter of personal preference, but it should be borne in mind that if you entrust all your world-attitude to third-party services, then in fact they will live your lives for you. After all, life is what we do personally. And in order to be Robinson Crusoe, or an astronaut, it is not enough to read books written on their behalf — you need to feel everything that they felt — they saw, heard, touched, smelled and ate. Observational astronomy is the experience of living the life of a being in contact with the Universe personally. And the galaxy M74 (NGC 628) can be seen with your own eyes — it is visible in amateur telescopes. But it is visible at the limit — it is guessed when looking at it with peripheral vision, and it is for this feature that it received the name "Ghost Galaxy". That is the name of this music album too.

Secondly, the "Ghost Galaxy" M74 is a classic example of a spiral galaxy, which is visible from the Milky Way Galaxy in flatwise. Others — even closer and brighter "star cities" — the Andromeda Nebula, the Triangulum Galaxy, the Bode Galaxy in Ursa Major — all of them are visible in half a turn. And for astronomers, it is important to see the galaxy without unnecessary distortion in order to better understand the structure of the spiral arms. And this galaxy provides scientists with such an opportunity. There are other spiral galaxies visible in flatwise. But they are far away from us. "Ghost Galaxy" is one of the closest.

The galactic world has its own concepts of "far" and "close". At the dawn of extragalactic astronomy, no one could have imagined how far these strange smoky specks in the sky, which differ from other nebulae in their special spiral structure, were so far away. It turned out that light travels distances between galaxies in millions of years, tens and even hundreds of millions ... however, there is not even any range limit here (at least for now).

But, thanks to Albert Einstein, everything is relative. And galaxies that are several tens of millions of light years away from the Milky Way are considered our close neighbors.

Determining the distances to galaxies is not an easy task. For the first time this was done 100 years ago, when variable stars, Cepheids, were discovered among the stars of the Andromeda galaxy. For such stars, there is a solid relationship between the period of change in brightness and luminosity. By measuring the period and apparent brightness of a star, astronomers were able to find out how far away this star is, and with it the entire Andromeda Nebula. But the Andromeda Nebula is only two and a half million light-years away. What about galaxies located much further away, which cannot be separated by telescopes into individual stars?

This is where supernova explosions come in. In every galaxy, massive stars die from time to time, and their death is accompanied by an explosion of enormous power — for a couple of weeks, a supernova star burns as brightly as an entire galaxy. At distances of tens of millions of light years, the star cannot be seen separately from other stars in the galaxy, but the brightness of the flash can be measured and the distance calculated.

In our galaxy, a supernova explosion was last observed in 1572 — even before the invention of the telescope. But in other galaxies, astronomers notice supernovae regularly.

In recent years, the "Ghost Galaxy" has delighted scientists with supernova explosions three times — in 2002, in 2003 and in 2013. For astrophysicists, this is "just some kind of holiday." Thanks to a series of these events, the distance to the M74 galaxy was measured quite accurately — 35 million light years.

What precision is implied in intergalactic distance scales?

Everything is relative here too. When it comes to the closest galaxies (Andromeda Nebula or Triangulum Nebula), a spread of a hundred thousand light years can be considered a good accuracy. And for the Galaxy M74, distance measurement accuracy is achievable within plus-minutes of 5 million light years. Therefore, in different sources, information about the remoteness of the "Ghost Galaxy" from us may differ.

But, we don’t need to know this distance to the nearest kilometer yet. And when we learn how to teleport from galaxy to galaxy, distances will no longer be important at all.

It is assumed that all galaxies are interconnected by hyperspace tunnels, the entrances to which are black holes — the same "star cinders" that remain at the site of the outbreak of some supernovae. In addition, supermassive black holes (having a mass of millions of solar masses) exist at the centers of most spiral galaxies. But at the center of the Phantom Galaxy, astronomers have discovered an intermediate-mass black hole — much more massive than the classic black hole that a dying giant-star turns into, but still not as gigantic as the black hole at the center of the Milky Way — not millions of solar masses, but only about ten thousand (although this is a lot).

It is worth noting that the "Ghost Galaxy" itself is somewhat more modest than the Milky Way and the Andromeda Nebula. It contains about 100 billion stars (our Galaxy has about 200 billion stars), although it is only slightly smaller than the Milky Way in size.

But, what certainly cannot be denied to her is the galactic charm — "Ghost Galaxy" is very beautiful. Due to the good location, its spiral branches are visible in all details. Its fractal structures are fascinating — it seems that this "space snail" whirl inside itself endlessly (which is not far from the truth).

The M74 galaxy has recently been photographed by all the major telescopes of the Earth, and even orbiting robotic telescopes. In the photo from the James Webb Space Telescope, the galaxy looks a little strange, but this is due to the fact that the JWST — an infrared telescope — it registers thermal radiation, and most bright stars are outside its sensitivity range. But the strings of gas and dust clouds are clearly visible, in which young stars are born. The Hubble Telescope captured the lace of spiral arms in detail, but the entire galaxy did not fit into the field of view. Therefore, for the cover of the album, I chose a picture taken on Earth — at the observatory of the Arizona University by astronomer Adam Block.

Tracklist

1.	Phantom galaxy	62:00

Credits

released November 21, 2022

Andrey Klimkovsky - music
Adam Block (Arizona University) - cover photo

License