The image below shows Polaris and surrounding stars within a 5 degree field of view. The image was taken within the past 10 minutes and is updated every 10 minutes. Image Copyright 2004.

Click on the image for more...

When the telescope and camera are active, the image above will appear with a greyscale color as the examples below show. When the camera and telescope are not taking data, then you see a greyscale archived image of the Polaris region.

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EXAMPLES OF WHAT YOU'LL SEE

If the Real Time image you see is like the one above, it is a deep image taken with a long exposure time. This type of image is taken for the study of transients and fainter variables.

If the Real Time image you see looks like the image above, it is a short exposure image. This type of image is taken to measure the light curve of Polaris.

If the Real Time image you see looks like the image above, the sky is covered with clouds. The bright specks you see are the camera pixel.

Polaris is reknown throughout the world as the guiding light, a reliable messenger allowing travelers to find their way. Unbeknownst to our ancestors, the dependable light of Polaris actually fluctuates in time; in fact, the ampitude of it's fluctuations vary in time. Thus, Polaris, a Cepheid variable, presents an intriguing and compelling astronomical study.

Polaris, the brighest star of the constellation Ursa Minoris is located at the tip of the handle of the Little Dipper. As the brightest of all Cepheid Variables, Polaris has been closely monitored in the past by many astronomers. Beginning after 1945, such astronomers noticed a rate of increase in Polaris' period as well as a rate of decrease in it's amplitude. It was then suggested in 1993 that Polaris would cease all pulsations within the next few years. Much to everyone's surprise, in 1998 astronomers noticed that Polaris did not cease pulsating - furthermore, it's amplitude decrease also stopped. With such unpredictable behavior, much is still left to be discoverd about Polaris. The amplitude of Polaris' variations is about 0.03 mag, and it's period is 3.97 days. Some astronomers suspect that we have been witnessing the evolution of Polaris as a Cepheid Variable: that this may be the process by which a Cepheid Variable evolves out of pulsating in it's first overtone to pulsating with its fundamental period - resulting in a more stable and stereotypical Cepheid Variable. This Project seeks to monitor Polaris continuously, providing live images of Polaris and a data base for continuous light curves of Polaris.

The telescope is a 10 cm refractor and the camera is an SBIG STV CCD. The field of view is about 5 degrees and the telescope is kept stationary. A specialized computer program was written to control the ccd. The program allows the user to set the exposure time and the interval of time between exposures. The program runs autonomously. The Polaris telescope is located in the the North Star building of the optical ridge at PARI. The building is equipped with a 24 inch X 26 inch window and is of course oriented due North. Imaging begins when the window shutter is opened and ends when the shutter is closed. Another program monitors weather conditions and opens/closes the shutter at sunset and sunrise, respectively. The images are analyzed using IRAF, resulting in a continuous light curve of Polaris.

• Alpha Ursa Minoris
• Polaris
• North Star
• Pole Star
• Load Star
• SAO 308
• HD 8890
• HIP 11767

Amplitude Variation: 0.03 mag

Period: 3.97 days

Variable Type: Cepheid

Spectral Type: F7:Ib-IIvar to 8:Ib-IIvar

Angular Distance from North Celestial Pole: 0.8 degrees

Mythology of Polaris

Current Status

Sunday, June 12, 2005

14 October, 2004: the Polaris telescope began observations.

15 February 2005: more than 4,000 images have been taken.

Usage Guidelines

This is a webbased telescope and data is automatically sent to the Internet for education/public outreach.