what is a galaxy and, how many different kinds are there joson anjo c. casillan vii- amorsolo
TRANSCRIPT
What is a Galaxy and, how many different kinds are there
Joson Anjo C. CasillanVII- Amorsolo
What is a galaxy
• Massive• Gravitationally bound• Stars• Stellar remnants• Dust and dark matter
Stellar Remnants
• White dwarfs• Neutron stars• Other exotic dense stars• Black holes
Stellar evolution
• The cycle of stars• Stellar evolution is the process by which a star
undergoes a sequence of radical changes during its lifetime.
How many different kinds of galaxy are there
• Elliptical• Spiral• Barred spiral• Irregular• Peculiar
Elliptical
• An elliptical galaxy is a type of galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile.
Spiral• Spiral galaxies consist of a flat,
rotating disc containing stars, gas and dust, and a central concentration of stars known as the bulge. These are surrounded by a much fainter halo of stars, many of which reside in globular clusters.
Barred spiral
• A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in approximately two-thirds of all spiral galaxies.
Irregular
• An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy.
Peculiar
• A peculiar galaxy is a galaxy which is unusual in its size, shape, or composition.
References
• http://www.apodnasa.gov• http://www.newscientist.com• http://ibp.fieldofscience.com• http://en.wikipedia.com