The Andromeda galaxy harbors
about 500 000 000 000 stars.

Final Answers
© 2000-2020 Gérard P. Michon, Ph.D.

Galaxies

The Milky Way is the name given to the star system that harbors our Sun.
The local group is dominated by the Milky Way & Andromeda galaxies.
The virgo cluster dominates our corner of the Universe.
Superclusters are the largest objects in the Universe.
Spiral galaxies. Andromeda and the Milky Way are examples..
Ring galaxies a rare type of galaxies, difficult to classify.
Elliptical galaxies Old galaxies. The largest we know is IC 1101.
Supermassive black holes at the core of almost all galaxies...

Stellar Objects.
Star Magnitudes.
The Solar System.
General Relativity.
Newtonian Gravity.
Cosmology 101: Studying the Universe as a whole.
Kant's Island Universes: The Universe is filled with separate galaxies.
Nemesis: A distant companion to the Sun to explain extinction periodicity.
Sand and Stars. The number of grains in a heap of sand as big as Fujiyama.

Videos

Powers of Ten : The classic short film (9 min) rereleased in 1977.
The definitive guide to the Milky Way galaxy National Geographic Channel.
Monster of the Milky Way BBC Nova (Eric Becklin & Andrea Ghez, UCLA).

Galaxies and the
Fabric of the Universe

(2012-07-14) The Milky Way The name of our own galaxy.

The Milky Way (latin: Via Lactea) is the dim stripe of nebulous light which can be seen on a clear night in the direction of Sagittarius. It's a fabulous side view of the disk-shaped system that includes our Sun and billions of other stars like it. In modern times, a huge number of such systems were discovered.

The Milky Way is significantly larger than early estimates had indicated. In December 2012, it was deduced from years of observations by the Hubble Soace Telescope that the neighbohring dwarf galaxy known as Leo 1 is in orbit around the center of the Milky way at a speed comparable to our Sun's own orbital speed.

To create the corresponding gravitational pull, the total mass of the Milky Way ought to be 1.6 trillion solar masses or so (counting everything, dark matter spherical halo and all, at a lesser distant from the galactic center than Leo 1 itself).

The definitive guide to the milky way galaxy NASA, JPL, National Geographic Chanel.
Space Fan News #84 by Tony Darnell (2012-12-04).
Wikipedia : Galaxy rotation curve

(2012-07-14) The Local Group of Galaxies

The Andromeda Galaxy and the Milky Way dominate our local cluster.

The Pinwheel Galaxy in Triangulum
(M33 or NGC 598) may contain
about 40 000 000 000 stars.

M33: The Pinwheel Galaxy in Triangulum
(NGC 598) has about 40 000 000 000 stars

The third largest member of the local group is the Pinwheel Galaxy (located in the Triangulum constellation). It contains about 40 billion stars and is thus only about one tenth the size of either the Andromeda Galaxy or the Milky way...