Thursday, 18 November 2010

Laboratorium Astrofisika

Astrophysics Laboratory

  “Life is either a daring adventure or nothing.”

"Hidup adalah petualangan yang membutuhkan keberanian, bila tidak itu bukanlah hidup."

Harvard-Smithsonian Center for Astrophysics
60 Garden Street, Cambridge, MA 02138

H-R Diagram of M67 using the Clay Telescope
Instructors: Allyson Bieryla and Jonathan Grindlay
The Clay Telescope is located on the roof of the Science Center. It is a 16" telescope equipped with a CCD (charged coupled device) imager. This project is divided into three main parts. First you will learn to use the telescope to observe and image the open cluster M67 in B and V filters. We will probably need no more than three nights of observing to accomplish this, but that is just an estimate. We will then learn how to process the images using IRAF (Image Reduction and Analysis Facility) software. 

This software will enable us the tools to reduce the data, subtracting away the inherent biases of observing. We will also use IRAF to do the actual photometry to determine the magnitudes of the stars in the cluster in both B and V fields. Finally we will create an Hertzsprung-Russell diagram, which plots the V magnitude vs. B-V magnitude. This shows where the stars in the cluster are on the main sequence. From this diagram, we can estimate the cluster's age and determine the approximate distance to the cluster. Also, knowing the angular width of the CCD image and the distance to cluster, we can approximate the number of stars in a single image to get a rough density of stars in the cluster. 

Laboratory Astrophysics
Science is successful because the physical laws we discover on Earth work everywhere and every when. We use laboratory experiments to expand our understanding of physical processes and then apply these results to the processes throughout the Universe. In some cases laboratory experiments can reproduce similar physics. For example, highly charged plasmas can be created in the laboratory to study the collisions between electrons and ions that occur in the hot solar corona. In other cases, such as in the extreme environments of black holes, we cannot reproduce the conditions. However, even in those cases, the pattern of observed spectral signatures allows us to identify the species and determine some of the physical conditions and processes. Spectral features observed in the solar corona are also observed from black hole sources.  

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