Hello!

These are some members of my family, including Dr. John Glaspey, my husband.

I am Dr. Katy Garmany. I’m an astronomer at Kitt Peak National Observatory.

A short history of telescopes

…almost 400 years ago lenses were combined to make a telescope, and a telescope was pointed to the sky by the Italian scientist Galileo

The vast nighttime sky, points of light, until…

With the first telescope, points of light in the sky took on shape

Saturn

Venus: phases like …

Jupiter and its moons

The Moon

The stars inOrion’s sword

But lenses have problems in telescopes

Images are surrounded by colored rings

Issac Newton: built a telescope from mirrors, not lenses

This solved the problem of colored rings, and other problems as well

Telescopes: light buckets!

The greater the diameter of the lens or mirror, the more light it collects - and the fainter the object we can see

Stars seen with larger and larger telescopes

Recording what we see

Photographic film: in 1850, the first permanent images recorded, but wet emulsions were very slow, and long exposures were needed

“dry” emulsions made astrophotography much easier!

First image of the moon, 1852Which brings us to the modern

era…

The Modern Era

From Refractors to Reflectors

These provide gains in “efficiency”:•Collecting more light for the instrument•Covering more sky per image•And we can actually make large mirrors, whereas really large lenses are impossible.

An older Refracting Telescope

The 0.9 meter Lick Refractor on Mt. Hamilton, CA

Versus a 35 year old reflecting telescope

The 4 meter Mayall telescope at Kitt peak

Versus a very modern and very large Reflecting Telescope

The 8 meter Gemini North telescope at Mauna Kea

• But astronomers are at the mountain to use the instrument, not (really) the telescope!

• We have given up the magic of the darkroom (photography) for the mystery of electronics and computers

GMOS GNIRS

on Gemini North

The Future

On to 20 meter and 30 meter telescopes made by putting multiple 8 meter mirrors on one large mount

The Giant Magellan Telescope Project