Astro4GirlsSunnyvale Library

Mar 20, 2012

What is Infrared light?

Light itself is made up of lots of different “colors”. Raindrops and prisms pull those colors “apart”.

But … there is more light that we can’t see, both here ……………….. and here

EVERYTHING THAT OUR EYES SEE IS WITHIN THIS SMALL WAVELENGTH RANGE!

ELECTROMAGNETIC RADIATION SPECTRUM

DIFFERENT WAVELENGTHS CAUSE DIFFERENT “COLORS” OR TYPES OF “LIGHT”!

Why Infrared Astronomy?

Infrared observations probe temperature differences within Infrared observations probe temperature differences within otherwise fairly cool things otherwise fairly cool things

WHY INFRARED ASTRONOMY?

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Texas Christian University March 5, 2010Visible Near Infrared Mid-Infrared

At visible ’s, the star forming region appears as a dark nebula, heavily obscured by interstellar dust.

At near-infrared ’s, the dust is nearly transparent, revealing the dust-enshrouded stars in their formation phase

Mid and far-IR observations trace dust emission

Different wavelengths give unique information:

Spectroscopy: another kind of picture-taking

Spectroscopy is like taking a picture of the light from something, spreading into a rainbow and recording that rainbow. Infrared spectroscopy is just imaging the infrared rainbow of an object

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Infrared spectrum is filled with lines created by molecules measurement of the strengths of these lines provides information regarding the temperature and composition.

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http://www.geologywales.co.uk/storms/index.htm

The stratosphere’s “temperature inversion” minimizes air turbulence, giving SOFIA: (1) a smooth ride, … and … (2) a nearly water-free environment

SOFIA

The Earth’s atmosphere is full of water

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Water in the atmosphere is BAD for infrared observations

SOFIA FLIES HIGH, WHERE THE INFRARED LIGHT IS!

Occultation Astronomy with SOFIA

Earth

Motion of Occulting Object

Shadow of Occulting Object

MOBILITY!

Pluto occultation light curve observed on SOFIA on June 23, 2011

Time

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Example of a Flight Path

http://www.astropix.com

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AN INSIDE LOOK …

Primary Mirror

Pressure Bulkhead

Light Tube

Spherical Hydraulic Bearing

Secondary Mirror

Infrared Light Mirror

Visible Light Mirror

HOW SOFIA WORKS

PRIMARY MIRROR

PRESSURE BULKHEAD

SCIENCE INSTRUMENT

(But first, let’s get oriented!)

Primary MirrorVisible Light Camera

Pressure Bulkhead

Light Tube

Spherical Hydraulic Bearing

Secondary Mirror

Infrared Light Mirror

Visible Light Mirror

Infrared Instrument

HOW SOFIA WORKSIncoming Infrared Light

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