GalaxiesGalaxies

Big Things in the UniverseBig Things in the Universe

““Billions and Billions”Billions and Billions”

- Carl Sagan- Carl Sagan

““Nebula”Nebula”

The early astronomers looked up at the The early astronomers looked up at the sky and kept seeing “faint fuzzy” things. sky and kept seeing “faint fuzzy” things. They named them “Nebula” – which They named them “Nebula” – which means “cloud”means “cloud”

Their telescopes weren’t all that good Their telescopes weren’t all that good

Charles MessierCharles Messier

Messier wanted to discover comets! He’d Messier wanted to discover comets! He’d look up, see a “faint fuzzy” patch – which look up, see a “faint fuzzy” patch – which is also what a new comet looks like – get is also what a new comet looks like – get excited – then notice that it didn’t move.excited – then notice that it didn’t move.

Frustrated, he made a list of 103 “faint Frustrated, he made a list of 103 “faint fuzzies” so he wouldn’t get distracted.fuzzies” so he wouldn’t get distracted.

He is more famous for the He is more famous for the Messier ListMessier List than for the comets he than for the comets he diddid discover. discover.

Faint Fuzzies RevealedFaint Fuzzies Revealed

Telescopes got better – people realized Telescopes got better – people realized that some of the Messier objects were gas that some of the Messier objects were gas clouds (M42), some were exploded stars clouds (M42), some were exploded stars (M1), some were groups of stars (M45), (M1), some were groups of stars (M45), and some were vast groups of billions of and some were vast groups of billions of stars (M31, M51, M101). stars (M31, M51, M101).

Hubble finally saw specific kinds of stars in Hubble finally saw specific kinds of stars in M31 – Andromeda – and discovered how M31 – Andromeda – and discovered how far away it was.far away it was.

Hubble and the GalaxiesHubble and the Galaxies

While he was working on the expansion of While he was working on the expansion of the universe, Hubble saw a LOT of the universe, Hubble saw a LOT of galaxies. He noticed they had several galaxies. He noticed they had several basic shapes.basic shapes.EllipticalElliptical EESpiralSpiral SSBarred SpiralBarred Spiral SBSB IrregularIrregular IrrIrr

Hubble came up with an identification Hubble came up with an identification system called the Hubble Tuning Fork.system called the Hubble Tuning Fork.

EllipticalElliptical

An Elliptical An Elliptical (M60) and a (M60) and a SpiralSpiral

Elliptical IIElliptical II

Two Two Ellipticals – Ellipticals – (M105) +(M105) +

SpiralsSpirals

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

Spirals IISpirals II

M101M101

Spirals IIISpirals III

NGC 891NGC 891

Spirals IVSpirals IVM104M104

Spirals VSpirals V

Stephans Stephans QuintetQuintet

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

HHEERRCCUULLEESS

CCLLUUSSTTEERR

Barred SpiralsBarred Spirals

Jalf Jalf 350350

Barred Spirals IIBarred Spirals II

M109M109

Barred Spirals IIIBarred Spirals III

Barred Spirals IVBarred Spirals IV

NGC 7479NGC 7479

Barred Spirals VBarred Spirals V

NGC 613NGC 613

from ESOfrom ESO

Barred Spirals VIBarred Spirals VI

NGC 4548NGC 4548

Barred Spirals VIIBarred Spirals VII

NGC 7479NGC 7479

IrregularsIrregulars

LL

MM

CC

SMC

Irregular IIIrregular II

LMCLMC

Irregular IIIIrregular III

M82M82

Irregular IVIrregular IV

NGCNGC

44494449

Irregular VIrregular V

NGC 6822NGC 6822

The Mystery of the GalaxiesThe Mystery of the Galaxies

One of the cool debates going on now in One of the cool debates going on now in Cosmology (the study of the origin of the Cosmology (the study of the origin of the Universe), is the question of: Did stars Universe), is the question of: Did stars form and “fall into” galaxies, or did form and “fall into” galaxies, or did galaxies (clumps of gas) form and then the galaxies (clumps of gas) form and then the stars formed and ignited.stars formed and ignited.

Both groups argue that there isn’t enough Both groups argue that there isn’t enough time for the other groups hypothesis to time for the other groups hypothesis to work. work.

Make a Galaxy ActivityMake a Galaxy Activity

You now know the basic shapes of the You now know the basic shapes of the galaxies. Choose one of the basic shapes galaxies. Choose one of the basic shapes and draw it on the top of a paper plate.and draw it on the top of a paper plate.

Put your name / period / date on the bottomPut your name / period / date on the bottomPut the type of galaxy shape it is E-S-SB-I on the Put the type of galaxy shape it is E-S-SB-I on the

bottom.bottom.

We will suspend them from the ceiling, We will suspend them from the ceiling, and hopefully they will not blow down!and hopefully they will not blow down!

DisclaimerDisclaimerAlohaAloha

I put together these power points for use in I put together these power points for use in my science classes.my science classes.You may use them in your classes.You may use them in your classes.

Some images are public domain, some Some images are public domain, some are used under the fair-use provisions of are used under the fair-use provisions of the copyright law, some are mine. the copyright law, some are mine. Copyright is retained by the owners!Copyright is retained by the owners!

Ted BrattstromTed Brattstrom