In light of NRAO's new cooperative agreement, this page is being hosted here temporarily until it migrates to

More information...

Using the 40-Foot Telescope

This is the primary telescope used by educational groups visiting through our Radio Astronomer for a Day program. Student groups ranging from 5th graders to graduate students learn to use the telescope and work on inquiry-based projects to investigate the radio universe just like professional radio astronomers.

The 40' is also used annually by participants of:
Chautauqua Short Course
Green Bank Star Quest
Society of Amateur Radio Astronomers
Pulsar Search Collaboratory
Space Public Outreach Team
In addition, amateur astronomers routinely make use of this telescope.

Useful Links:

History of the Forty-Foot
The Forty-foot Observer's Manual (
Example Forty-Foot Data (ascii) (
Program to Convert Standard Time to LST

In the Example Data in ascii format, you will see four columns of numbers: Right ascension (celestial longitude), declination (celestial latitude), data points for each of our two receiver channels: Channel A and B. Forty-foot calibration numbers are given for the time when the data was collected. These may not be current values. The best way to view this data is to import it into a spreadsheet and create a graph. Microsoft Excel works well. Graphed, the data will then resemble a strip-chart recording. Those of you who have used the Forty-foot, will immediately know what to do at that point!

40ft1The 40Foot Educational Telescope. Credit: NRAO/AUI/NSF

40ftstudentsinsideStudents collect their own radio data on a chart recorder. Credit: NRAO/AUI/NSF