Galaxies Big Things in the Universe Billions and Billions - Carl Sagan - Carl Sagan

Nebula The early astronomers looked up at the sky and kept seeing faint fuzzy things. They named them Nebula – which means cloud The early astronomers looked up at the sky and kept seeing faint fuzzy things. They named them Nebula – which means cloud Their telescopes werent all that good Their telescopes werent all that good

Charles Messier Messier wanted to discover comets! Hed look up, see a faint fuzzy patch – which is also what a new comet looks like – get excited – then notice that it didnt move. Messier wanted to discover comets! Hed look up, see a faint fuzzy patch – which is also what a new comet looks like – get excited – then notice that it didnt move. Frustrated, he made a list of 103 faint fuzzies so he wouldnt get distracted. Frustrated, he made a list of 103 faint fuzzies so he wouldnt get distracted. He is more famous for the Messier List than for the comets he did discover. He is more famous for the Messier List than for the comets he did discover.

Faint Fuzzies Revealed Telescopes got better – people realized that some of the Messier objects were gas clouds (M42), some were exploded stars (M1), some were groups of stars (M45), and some were vast groups of billions of stars (M31, M51, M101). Telescopes got better – people realized that some of the Messier objects were gas clouds (M42), some were exploded stars (M1), some were groups of stars (M45), and some were vast groups of billions of stars (M31, M51, M101). Hubble finally saw specific kinds of stars in M31 – Andromeda – and discovered how far away it was. Hubble finally saw specific kinds of stars in M31 – Andromeda – and discovered how far away it was.

Hubble and the Galaxies While he was working on the expansion of the universe, Hubble saw a LOT of galaxies. He noticed they had several basic shapes. While he was working on the expansion of the universe, Hubble saw a LOT of galaxies. He noticed they had several basic shapes. EllipticalE EllipticalE SpiralS SpiralS Barred SpiralSB Barred SpiralSB IrregularIrr IrregularIrr Hubble came up with an identification system called the Hubble Tuning Fork. Hubble came up with an identification system called the Hubble Tuning Fork.

Elliptical An Elliptical (M60) and a Spiral An Elliptical (M60) and a Spiral

Elliptical II Two Ellipticals – (M105) + Two Ellipticals – (M105) +

Spirals M51 – a spiral seen face on with a companion galaxy M51 – a spiral seen face on with a companion galaxy

Spirals II M101 M101

Spirals III NGC 891 NGC 891

Spirals IV M104 M104

Spirals V Stephans Quintet Stephans Quintet

Spirals VI (and some Ellipticals) Spirals VI (and some Ellipticals) HERCULESCLUSTER

Barred Spirals Jalf 350 Jalf 350

Barred Spirals II M109 M109

Barred Spirals III

Barred Spirals IV NGC 7479 NGC 7479

Barred Spirals V NGC 613 NGC 613 from ESO from ESO

Barred Spirals VI NGC 4548 NGC 4548

Barred Spirals VII NGC 7479 NGC 7479

Irregulars LMC SMCSMC

Irregular II LMC LMC

Irregular III M82 M82

Irregular IV NGC NGC

Irregular V NGC 6822 NGC 6822

The Mystery of the Galaxies One of the cool debates going on now in Cosmology (the study of the origin of the Universe), is the question of: Did stars form and fall into galaxies, or did galaxies (clumps of gas) form and then the stars formed and ignited. One of the cool debates going on now in Cosmology (the study of the origin of the Universe), is the question of: Did stars form and fall into galaxies, or did galaxies (clumps of gas) form and then the stars formed and ignited. Both groups argue that there isnt enough time for the other groups hypothesis to work. Both groups argue that there isnt enough time for the other groups hypothesis to work.

Make a Galaxy Activity You now know the basic shapes of the galaxies. Choose one of the basic shapes and draw it on the top of a paper plate. You now know the basic shapes of the galaxies. Choose one of the basic shapes and draw it on the top of a paper plate. Put your name / period / date on the bottom Put your name / period / date on the bottom Put the type of galaxy shape it is E-S-SB-I on the bottom. Put the type of galaxy shape it is E-S-SB-I on the bottom. We will suspend them from the ceiling, and hopefully they will not blow down! We will suspend them from the ceiling, and hopefully they will not blow down!

Disclaimer Aloha I put together these power points for use in my science classes. You may use them in your classes. Some images are public domain, some are used under the fair-use provisions of the copyright law, some are mine. Copyright is retained by the owners! Ted Brattstrom