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Remote Telescope Results

From AstroEd

Revision as of 07:46, 3 December 2013 by WikiSysop (talk | contribs) (What to Do)

Retrieving Your Data

The data we have available in response to your requests are on the server website at

http://www.astro.louisville.edu/shared_skies/archive/astrolab/108/

You may be asked for a username and password, and if so enter

  • User: astrolab
  • Password: asteroid

all in lower case.

This semester we have selected some of the best recent requested images and made them available to everyone for this lab activity:

NGC 7662 A planetary nebula in Andromeda

Messier 1 (M1) A supernova remnant in Taurus

Messier 33 (M33) A nearby spiral galaxy companion to our Milky WEay

Moon Seen this fall




Image files ending in "fits" must be downloaded to view in ImageJ, ds9, or Aladin. Other files may be viewed on the web.

Find an image file and right click on the name. Save the data to your own computer for use later. The "fits" files are astronomical image data types and usually very large so download will be slow. ImageJ is generally useful for all types of images, but you may find that ds9, which shows only astronomical FITS images, is a tool you like as well. Use what works best for you.

Using ImageJ

ImageJ allows you to view files of all types. It is particularly good for looking at tif images and also useful for some fits files. You can experiment with it -- the difficulties of software are part of the lab experience!

ImageJ is installed on the computers in the astronomy lab. If you prefer, to run a version of ImageJ on your notebook you may click below to go to the link:

http://www.astro.louisville.edu/software/astroimagej/imagej

You have a choice of downloading and installing the software, or running from our server. Either way, once imagej has started select "File" from its menu, "Open", and find the images you have downloaded. You might review your work on the Saturn unit to see what the different controls will do.

While ImageJ offers many image processing options, and allows you to build color images from individual images in each color, this easily installed version is not well suited to take full advantage of astronomical "fits" images, particularly those with a celestial coordinate system embedded in the file. Images of that type on our server have "wcs" in the file name and the extension ".fits". If you want to explore them, use Aladin or SAOImage ds9.


Using SAOImage ds9

SAOImage DS9 is an astronomical imaging and data visualization program that is widely used for research. It is installed on the lab computers and you may find it the best way to view and measure astronomical FITS files. It is free software, and can be installed on Mac, Linux and Windows computers if you prefer to run it on your own. It is not a web application, and the files you use it with must downloaded to your computer first. For more information if you are working outside the lab, go to this link

http://hea-www.harvard.edu/RD/ds9/


Using Aladin

Aladin is ideal for viewing most fits files because it handles astronomical coordinates, and also allows you to overlay images from different sources. However, it does not do image processing particularly well, and if you want to modify an image a lot you may need ImageJ. The link to Aladin is

http://www.astro.louisville.edu/software/aladin/

Use "File" and "Open local file" in the Aladin menu to view an image you have already downloaded. You may install Aladin on your computer. It is safe, free, and reliable.


In the Lab

Although the software will run on your notebook or home computer, and the data are available over the network, we ask that you do the work in the lab so that the assistant can help, and you can discuss your ideas with other students. You must submit your results in the lab that day.


What to Do

Now that you have the software and the data, you are probably wondering what to do with it.

You might begin by comparing the data with what you can find on the Internet too, perhaps in Wikipedia or an image search, but remember that the focus should be on the data you from our telescopes. It will be quite different from the pretty pictures you may get from the Hubble Telescope or press releases from ESO.

To give you some ideas, here are questions you might seek answers to:

In Messier 1, there are two central stars. Which one is a Pulsar? Does it have a different color from the other one. Why are the filaments red? Why is the fuzzy nebula "gray"? If this is the remnant of a supernova that occurred in 1054 AD, what is its 3-dimensional shape (you are only seeing it projected onto the sky)?

In NGC 7662, what 3-dimensional shape could make the object look like this? There are images taken in filters isolating light from hydrogen, sulfur, and oxygen. Is there a difference in where these features appear in the nebula? Measure how large NGC 7662 is in diameter on the sky (an angle), and look up its distance with help from Google. See if you can figure out how large in diameter it must be compared to our solar system. (Your assistant may help if you get stuck.)

For Messier 33, the Triangulum Galaxy, can you find "nebulae" in its spiral arms? Is M33 bigger or smaller than the Milky Way? How long ago did the light that made this image (in November 2013) leave the galaxy?

For the Moon, look for famous named craters. Find Copernicus, Tycho, Plato, Mare Imbrium, the lunar Appenines, and Sinus Iridum. How big are the? That is, how many kilometers across are they? Why are shadows longer for craters and mountains close to the "terminator", the line that divides the light and dark sides. Are the craters that are near the top or bottom (north or south) really oval, and if not, why do they appear to be oval? How did the floor of Mare Imbrium or of Plato become so free of craters?




This unit is an open ended inquiry. Start with the data we have provided and see where it takes you. Describe what you did and your conclusions in your response. Remember that typically discovery-based science generates new questions, and you may suggest other inquiries as part of your conclusion. Even if you work in small groups in the lab, each student must submit their own work at the end of the lab period.