Radio astronomy uses radio telescopes and receivers to capture radio waves emitted by astronomical objects like stars, galaxies, and nebulae. Radio telescopes work similarly to optical telescopes but detect radio waves rather than visible light. They capture radio emissions that can reveal information about phenomena like cold molecular clouds, strong magnetic fields, and relativistic electrons. Radio astronomy allows observation of regions that are obscured at optical wavelengths. Interferometry combines signals from multiple telescopes to achieve higher resolution. Common radio sources observed include galaxies, nebulae, stars, and active regions in our own and other galaxies.

1. Radio Astronomy
Image courtesy of
NRAO/AUI
Image courtesy of
NRAO/AUI

2. Image courtesy of NASA

3. Image courtesy of Snapped by:
NRAO/AUI Vallian
M51
Whirlpool
Galaxy
Image courtesy of
NRAO/AUI

4. Optical Radio
Telescope Telescope
CCD Array Radio Receiver
Noise Noise
Correction Correction &
Assembly

5. Telescopes and Resolutions
Image courtesy of
Images courtesy of
NRAO/AUI
Paul Lowell
Image courtesy of Images courtesy of
NRAO/AUI Paul Lowell
Image courtesy of
NRAO/AUI
Images courtesy of
Paul Lowell
Image courtesy of
NRAO/AUI Image courtesy of
NRAO/AUI
Image courtesy of U.
Manchester
Cygnus A
Radio
Source
Images courtesy of Image courtesy of
Paul Lowell NRAO/AUI

6. Very Large Array Australia Telescope Compact
Array
Image courtesy
Image courtesy of of ATCA
NRAO/AUI
Interferometry Very Long Baseline
Interferometry
Signal from one
telescope.
Signals from a pair of
telescopes combined.

7. Noise
Suspected USAF Flyovers
Distant thunderstorm
Image courtesy of Paul
Sunset Lowell
Images courtesy of
Paul Lowell
Star Same star w/ nearby satellite
Image courtesy of
Christian Wolff
Image courtesy of
NRAO/AUI

8. Radio Sources
 Cold Molecular
Clouds
• Neutral Hydrogen
• Complex
molecules
 Strong Magnetic
Fields
• Decelerating
relativistic
electrons
• Quasars, Pulsars,
Supernova
Remnants, Active
Galaxies
Image courtesy of
NRAO/AUI

9. Snapped by:
BigDipper
Image courtesy of
NRAO/AUI
M17
Swan Nebula
Image courtesy of
NRAO/AUI

10. Image courtesy of
NRAO/AUI
Snapped by:
Astroman
Antenna
Galaxies
Image courtesy of
NRAO/AUI

11. M42
Orion Nebula
Snapped by:
KathyC
Image courtesy of
NRAO/AUI
Image courtesy of Image courtesy of
NRAO/AUI NRAO/AUI

12. Betelgeuse
Inset courtesy of Snapped by:
Snapped by: NRAO/AUI orion1958
orion1958
Jupiter and Saturn
Inset courtesy of Snapped by:
Image courtesy of NRAO/AUI JoshuaH
NRAO/AUI

13. M33
Snapped by: Image courtesy of Image courtesy of
ralphd050702 NRAO/AUI NRAO/AUI
M81
Image courtesy of Image courtesy of
Snapped by: selby
NRAO/AUI NRAO/AUI

14. M84
Snapped by: astroman
Image courtesy of
NRAO/AUI
M87
Snapped by: marleen
Inset courtesy of
NRAO/AUI

15. Karl Jansky
Image courtesy of
NRAO/AUI
Jansky = Jy =10-26 Watts / m2 / Hertz

16. For More Info
 Society of Amateur Radio Astronomers
www.radio-astronomy.org
 National Radio Astronomy Observatory
www.nrao.edu
 Pisgah Astronomical Research Institute
www.pari.edu

17. NGC 5128 (Centaurus A)
Image courtesy of
NRAO/AUI
Snapped by:
Plowell

18. Image courtesy of
NASA