Variable, as an ellipse is not a perfect circle.
That's a bit tricky. Each type of galaxy has a wide range of sizes, so you can't say, for example, that any elliptical galaxy is larger than any spiral galaxy - because they aren't - though I believe that elliptical galaxies do have a general tendency to be larger than the other types.
Yes. Although if you are measuring the diameter of an atom, or a galaxy, you might consider other units to be far more suitable.
Elliptical galaxies have an oval shape. An example is the Messier 87.
The cart is before the horse. Before an example can be cited, we need a definition of elliptical energy. Come back when you have that.
Circumference of a circle is pi * diameter. Diameter is 2 * radius. So if you know the radius, circumference is 2 * pi * radius. Now choose an appropriate approximation for pi (3.14, or 3.1416, or even the fraction 22/7), depending on your application. This will work for ANY circle, no matter how big or small it is, as long as it's a true circle and not a different elliptical shape, e.g. an oval.
No, an EO galaxy is not a type of elliptical galaxy. They are a lenticular galaxy.
We live in a spiral galaxy, not in an elliptical galaxy.
An elliptical galaxy is a type of galaxy not a particular one.
An elliptical galaxy is an egg shaped galaxy that has an almost featureless image.
The largest known galaxy is elliptical
No. The Milky Way is believed to be a barred spiral galaxy.
An elliptical galaxy is round. A spiral galaxy is shaped like a spiral.
Elliptical Galaxy The Elliptical Galaxy has mostly old stars and blue stars are new stars.
The Andromeda Galaxy is a spiral galaxy.
An elliptical galaxy.
BL Lacertae is the active center of an elliptical galaxy.
There is a wide variation between all the different elliptical galaxies. They can be as small as a tenth of a kiloparsec to over 100 kiloparsecs. Our Galaxy, the Milky Way is approximately 30 kiloparsecs in diameter. A parsec is approximately 3.26 light years. The range is much broader than any other type of galaxy.