Abstract:We present data characterising the performance of the Mopra Radio Telescope during the period 2000-2004, including measurements of the beam size and shape, as well as the overall beam efficiency of the telescope. In 2004 the full width half maximum of the beam was measured to be 36 ± 3 at 86 GHz, falling to 33 ± 2 at 115 GHz. Based on our observations of Jupiter we measured the beam efficiency of the Gaussian main beam to be 0.49 ± 0.03 at 86 GHz and 0.42 ± 0.02 at 115 GHz. Sources with angular sizes of ∼80 couple well to the main beam, while sources with angular sizes between ∼80 and ∼160 couple to the both the main beam and inner error beam. Measurements indicate that the inner error beam contains approximately one-third the power of the main beam. We also compare efficiency corrected spectra to measurements made at similar facilities and present standard spectra taken towards the molecular clouds Orion-KL and M17-SW.

As computer-based visualization techniques are becoming more important across the landscape of astronomy education, this pre-test/post-test study using the Size, Scale, and Structure Concept Inventory (S3CI) looked at the impact of using a hybrid combination of hands-on and computer-based activities on the learning of five semesters of non-science majoring undergraduates learning about the concept of astronomical parallax. The hybrid laboratory activity comprises an outdoor component where students use the parallax method to determine the distances to nearby objects, and a computer visualization component using the American Astronomical Society’s WorldWide Telescope astronomical visualization software. This activity was implemented as part of an undergraduate astronomy course for non-science majors. Based on an analysis of student responses, we conclude that this activity can help students understand the parallax method as applied in the astronomical realm. However, even after instruction, students had difficulty recognizing this method as the primary means for determining distances in astronomy.

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