What is the difference between an SA and an Sc galaxy?
In Sa galaxies, the bulge dominates the galaxy, while in Sc galaxies, the bulge is much smaller. In Sa galaxies, the arms are tightly wrapped around the bulge, while in Sc galaxies the arms are much looser, and often appear to be more clumpy than the smooth arms of an Sa galaxy.
What is Hubble’s tuning fork classification system?
The diagram is roughly divided into two parts: elliptical galaxies (ellipticals) and spiral galaxies (spirals). Hubble gave the ellipticals numbers from zero to seven, which characterize the ellipticity of the galaxy – “E0” is almost round, “E7” is very elliptical.
What Hubble classification is the Milky Way?
Our own Milky Way is generally classed as Sc or SBc, making it a barred spiral with well-defined arms. Examples of regular spiral galaxies: (visually) M31 (Andromeda Galaxy), M74, M81, M104 (Sombrero Galaxy), M51a (Whirlpool Galaxy), NGC 300, NGC 772.
What are the four types of galaxy classifications?
Hubble’s Classification Scheme Go back to Lesson. Edwin Hubble developed a galaxy classification scheme consisting of four types: elliptical, spiral, barred spiral, and irregular. Three of these types are represented in the “tuning fork” diagram below.
What is the largest body in the universe?
The largest known ‘object’ in the Universe is the Hercules-Corona Borealis Great Wall. This is a ‘galactic filament’, a vast cluster of galaxies bound together by gravity, and it’s estimated to be about 10 billion light-years across!
Why is Hubble’s tuning fork wrong?
You can see why this diagram is called the Hubble tuning fork. We now know that he was wrong: galaxies do not move down the forks of the diagram as they evolve. We know this because spiral galaxies rotate quickly (on an astronomical scale), while elliptical galaxies do not.
Is the Hubble Tuning Fork accurate?
However, one of the key characteristics of the tuning fork system is a correlation between a spiral galaxy’s bright bulge and how tightly the arms are wound. A study using the citizen science project Galaxy Zoo has found that this correlation might not be as accurate as Hubble predicted.
How much bigger is Andromeda than the Milky Way?
They were surprised to find that the Andromeda galaxy’s halo stretches much, much farther out beyond the visible boundaries of the galaxy than previously known. In fact, it extends as far as half the distance to our Milky Way (1.3 million light-years) and even farther in other directions (up to 2 million light-years).
Who created the tuning fork diagram?
astronomer Edwin Hubble
What are the 3 parts that a spiral galaxy is made of?
Most spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as the bulge. These are often surrounded by a much fainter halo of stars, many of which reside in globular clusters.