The Hubble Tuning Fork Diagram organizes the classifications based on a galaxy's <1>. There are three classifications of galaxies known as spiral, elliptical, and <2>. The most discriminating feature of spiral galaxies is the presence of <3>. A normal spiral galaxy with a large nucleus and tightly wound spiral arms would be classified as <4>. Spirals typically have large amounts of gas and dust which allow star formation to occur while elliptical galaxies typically consist only of old stars. An elliptical galaxy that appears perfectly round would be classified as <5>. Most of the galaxies that we see are <6>.
Hubble's Law mathematically describes the fact that the universe is expanding. It specifies that the velocity of recession of a galaxy is proportional to its distance. Today the Hubble Contant is thought to be about <7> km/s*Mpc. Thus, a galaxy at a distance of 10 Mpc would have a recessional velocity of approximately <8> km/s. @ qu.1.1.blank.1=shape,luminosity,age,color@ qu.1.1.blank.2=irregular,amorphous,oval,diametric@ qu.1.1.blank.3=a disk,a spiral,old stars,young stars@ qu.1.1.blank.4=Sa,Sb,Sc,SBa,SBb,SBc@ qu.1.1.blank.5=E0,E3,E5,E7@ qu.1.1.blank.6=spiral,elliptical,irregular@ qu.1.1.blank.7=70,35,135,170@ qu.1.1.blank.8=700,350,1350,1700@ qu.1.1.grader.1=menu@ qu.1.1.grader.2=menu@ qu.1.1.grader.3=menu@ qu.1.1.grader.4=menu@ qu.1.1.grader.5=menu@ qu.1.1.grader.6=menu@ qu.1.1.grader.7=menu@ qu.1.1.grader.8=menu@ qu.1.2.mode=Blanks@ qu.1.2.editing=useHTML@ qu.1.2.name=Galaxies@ qu.1.2.question=
The Hubble Tuning Fork Diagram organizes the classifications based on a galaxy's <1>. There are three classifications of galaxies known as spiral, elliptical, and <2>. The most discriminating feature of spiral galaxies is the presence of <3>. A barred spiral galaxy with a small nucleus and loosely wound spiral arms would be classified as <4>. Spirals typically have large amounts of gas and dust which allow star formation to occur while elliptical galaxies typically consist only of old stars. An elliptical galaxy that is very elongated would likely be classified as <5>. The most common type of galaxy in the universe is a(n) <6>.
Hubble's Law mathematically describes the fact that the universe is expanding. It specifies that the velocity of recession of a galaxy is proportional to its distance. Today the Hubble Contant is thought to be about <7> km/s*Mpc. Thus, a galaxy with a velocity of recession of 350 km/s, would be at a distance of approximately <8> Mpc. @ qu.1.2.blank.1=shape,luminosity,age,color@ qu.1.2.blank.2=irregular,amorphous,oval,diametric@ qu.1.2.blank.3=a disk,a spiral,old stars,young stars@ qu.1.2.blank.4=SBc,Sa,Sb,Sc,SBa,SBb@ qu.1.2.blank.5=E7,E0,E3,E4@ qu.1.2.blank.6=elliptical,spiral,irregular@ qu.1.2.blank.7=70,35,135,170@ qu.1.2.blank.8=5,10,7,22@ qu.1.2.grader.1=menu@ qu.1.2.grader.2=menu@ qu.1.2.grader.3=menu@ qu.1.2.grader.4=menu@ qu.1.2.grader.5=menu@ qu.1.2.grader.6=menu@ qu.1.2.grader.7=menu@ qu.1.2.grader.8=menu@