Peter Oshkai photography

W5 is a large emission nebula located in the Cassiopeia constellation, close to the Heart Nebula (IC 1805). There are several open star clusters inside the Soul Nebula, including IC 1848, which is often used to identify it.

The Soul Nebula is a star nursery, where new stars are created practically before our eyes. In fact, most stars have been born in regions like W5, where hundreds or thousands stars form at the same time.

The Soul spans 300 light-years, which is about 100 times the distance from the Sun to the nearest star.

About a dozen of giant O-type stars are primarily responsible for creating this emission nebula. These giant stars are approximately 30 times heavier and 10,000 times more luminous than our Sun. This intense luminocity is mostly in the form of ultraviolet radiation. It forms a powerful stellar wind that ionizes gas molecules and drives them away from the giant stars, creating the bubble structure in the middle of the nebula. 

This structure contains gas pillars that point towards the stars that created them. The pillars form because the denser gas areas take longer to clear, while the material around them is swept away by the stellar wind. The compression of the gas molecules in the pillars accelerates their gravitational collapse and leads to formation of new stars.

In the Soul Nebula, there are at least three generations of star formation. Their light travelled for 6,500 years before reaching my camera in Victoria, BC in June of 2024.

IC 1805 is a faint, but huge emission nebula in the Cassiopeia constellation. It is about 330 light-years in diameter and has an angular size of 2 degrees – 4 diameters of the full Moon! The open star cluster in the centre of the heart (Collinder 26) creates intense stellar wind that drives the shape of the gas cloud and causes it to emit the intense red colour. Some of these stars are 50 times more massive than the Sun.

This light travelled for 7,500 years before reaching my camera in Victoria, BC in the early October.

M31 is the deep-sky object that made me want to do astrophography. This light travelled for 2.5 million years before reaching my yard in Victoria, BC in the early September.

The Andromeda is closest galaxy to our Milky Way Galaxy. It is 152,000 light-years in diameter, contains approximately 1 trillion stars and is moving towards us at 110 kilometres per second. Our galaxies will collide in about 4.5 billion years, eventually forming a single giant elliptical galaxy.

The chance of any stars colliding is actually negligibly small, because despite their great numbers, the distances between the stars are tremendous. The two galaxies will simply pass through each other, as they commonly do. In fact, the M31 itself merged with another galaxy 3 billion years ago.

However, both the Milky Way and the Andromeda galaxies have supermassive black holes in their centres, and when they eventually merge, they would form a quasar and release as much energy as about 100 million supernova explosions. According to the current models, there is a 12% chance that our Sun would get ejected from the new galaxy during the collision, in which case the star itself, as well as its planets would be undisturbed. However, if the Sun comes close to the new black hole, it would be torn apart by its gravity.

This will be of little consequence to the life on our planet, though, because much earlier than that, about 1 billion years from now, the Sun’s luminosity will increase by approximately 40%, and there will be no way for liquid water and terrestrial life to exist on Earth.

Time to introduce planetary engineering into our curriculum? 

NGC 7635 is a unique-looking emission nebula in the Cassiopeia constellation. It looks like a glowing bubble, and in some sense it is. It’s a shell of ionized H II gas blown out by a massive, hot young star SAO 20575. This central star has a visual magnitude of 8.7 and has a mass of 44 Suns. Its light travelled for 11,000 years before it hit my yard in Victoria, BC on June 7, 2024.