Galaxies
Galaxies are large groupings of stars held together by gravity. Galaxies are classified in three main groups. Spiral galaxies have a pinwheel shape. Our galaxy, the milky way, is a spiral. Another galaxy is called an elliptical galaxy, which has an elliptical shape, consists of little dust or gas, may be an older galaxy, and could have been formed from the merging of two galaxies. Lastly, an irregular galaxy has no defined shape. The cause of this may have been that a neighboring galaxy created the distortion by pulling on it.
Open star clusters are loose groupings of stars that formed together. These consist of newer hotter stars at about 100-1,000 stars. Globular star clusters form a halo around a galaxy and collect in very tight groups. There are usually 20,000-1,000,000 stars in t that are older.
Open star clusters are loose groupings of stars that formed together. These consist of newer hotter stars at about 100-1,000 stars. Globular star clusters form a halo around a galaxy and collect in very tight groups. There are usually 20,000-1,000,000 stars in t that are older.
Stars
Stars are created with a hydrogen fusion, which is the combining of atomic nuclei. Stars fuse 4 hydrogen atoms into 1 helium atom. The excess mass from this process is released as light & heat energy. Every element in a star gives off a signature color and produces an emmision spectrum. Stars also give off an absoribsion, or dark line spectrum that corrsponds to the emmison spectrum. by mathcing the lines, a stars composition can be determined.
Stars are classified by temperature. It goes from hottest to coolest. An easy way to remember this classification is this acronym: Oh be a fine girl kiss me (OBAFGKM) The color of a star is related to surface temperature. The rank from coolest to hottest, Red(coolest), yellow(warm), blue(hottest). Our sun is a yellow G-type star. The magnitude scale means the smaller the number, the brighter the object. A magnitude 1 is 100x brighter than a magnitude 6. Apparent magnitude is how bright a star appears from earth. Absolute magnitude is how bright a star actually is.
Stars are classified by temperature. It goes from hottest to coolest. An easy way to remember this classification is this acronym: Oh be a fine girl kiss me (OBAFGKM) The color of a star is related to surface temperature. The rank from coolest to hottest, Red(coolest), yellow(warm), blue(hottest). Our sun is a yellow G-type star. The magnitude scale means the smaller the number, the brighter the object. A magnitude 1 is 100x brighter than a magnitude 6. Apparent magnitude is how bright a star appears from earth. Absolute magnitude is how bright a star actually is.
The H-R diagram was developed by Hertzsprung and Russel. It shows the relationship between temperture and magnitude. Most stars fall along a diagonal line, called the main sequence. Our sun falls here to. The location on this diagram indicates the age of the star.
Different sizes of stars have different fates:
Small/Medium
1. Nebula 2. Protostar 3. Main Sequence 4. Red Giant 5. White Dwarf 6. Black Dwarf |
Large/Massive
1. Nebula 2. Protostar 3. Main Sequence 4. Red Giant 5. Supernova 6. Neutron Star/Pulsar |
Super-Massive
1. Nebula 2. Protostar 3. Main Sequence 4. Red Giant 5. Supernova 6. Black Hole |