Baker Observatory Lab Report

AST 311: Observational Techniques

Using the 8-inch telescopes at Baker Observatory

Missouri State University

Joshua W. Kern

Abstract

On September 30, 2015, we used an 8-inch telescope at Baker Observatory to take images of Saturn using the ST-I monochromatic CCD cameras without filters. Darks, flats, and sky darks were taken to reduce the science images in the future. The reduction of our science images should be completed by December.

Experiment

The purpose of this experiment is to become familiar with operating the 8-inch telescopes at Baker Observatory and obtaining reduced observational data of astronomical objects. After mounting the telescopes and plugging in the power supply, we checked the alignment of the finder scope with the telescope and focused the telescope. We then aligned the telescope to the sky using the two star align mode with Polaris and Altair. Using the preset objects programmed into the computer, we moved the telescope to view Saturn. We assured that Saturn was in the center of the field of view of the telescope and replaced the viewing lens with the ST-I monochromatic CCD camera. We took multiple test exposures to assure the telescope was in focus and then began taking science images. After obtaining 10 science images, we took 10 darks, 10 flats, and 10 sky images to use in the data reduction.

Results & Discussion

The science images we obtained of Saturn were taken with an integration time of 0.05 seconds and no filters were used. Maximum values for the counts in each image of Saturn are ~15,000 corresponding to the object itself. Two (possibly three) of Saturn's moons are visible in the images as well. An example of one science image is given below. 

 

However, this image is composed from the raw science data without corrections from the darks, flats, and sky images. Further data reduction will be needed in order to obtain data that is satisfactory for analyzing.

The 10 sky images were obtained for the purpose of correcting the noise caused by the light pollution from the sky. These were taken with the same integration time (0.05 seconds) and focus of the telescope as when the science images were being taken accepting that the images were taken of a nearly empty field of view near Saturn and not of Saturn itself. The other darks and flats were taken to correct for the instrumental errors in our data. They were taken with an integration time of 2 seconds due which was chosen due to the ability of the camera, while taking flats, to obtain reasonably high counts (>10,000). An example is given below of a dark, sky dark, and flat image respectively. 

 

This data should be sufficient to correct for instrumental and observational errors in our science images.