Welcome to http://www.handsonuniverse.org/activities/Explorations/ToolBox
Menu & Toolbars
|Open||Click Or, click on , and then Open.
Double click on the image icon. Or, click the image icon, then Open.
(You may have to go to and to .)
|Color||Click the arrow. Select a color.|
|Status Bar|| Put your curser over the central star of the Ring Nebula. Find an x,y
position and the brightness counts at that pixel in the status bar at the lower right hand
corner of the HOU window. For this image, you might find the central star of the
Ring Nebula is at the image pixel position: x: 618, y: 390; the brightness
counts in this pixel are 2217. Counts represent the amount of light
collected by the CCD camera at this pixel.
Look in the lower right corner of the HOU screen for a status bar with x: y: and Counts.
|Min / Max||Change the contrast in one of three ways. Click, drag, and release the red or blue tabs. Click the arrows. Or, click inside the boxes with numbers, backspace and type in new numbers. Write down the settings you like best. (Now go to and choose Reset Default Min/Max.)|
|Log||Click in the box in front of log. Log scales the colors in a way that allows you to see the dim parts of the image. Click again and the 'log scaling' display turns off.|
|Zoom||Click inside the box. Hold down the mouse and sweep over the number, or press Backspace or Delete. Replace with a new number like 2 or 3, up to 20. or press Enter or Return.|
Click on Data Tools, select Zoom Box. You will draw a box on your image. Use
zoom box to study a small area of an image.
|Clean Up||Click to erase marks from an image. Or, , .|
|Auto Aperture||Click on , move your cursor over a star. Click again. The number represents the star's total brightness counts. Use auto aperture to find the (x,y) position and brightness of any star.|
|Results Box||keeps a record of your data. When a window pops up, it may be in your way. Either click and drag the title bar of the window to move it out of the way. Or, click on File and choose Hide window. Or go to View and toggle Results to appear or hide.|
|Aperture||Go to the menu and choose . 7 and 14 are a good settings for most images. Click OK. Move your cursor over a star; click. Use aperture to control the size of the star area and sky area that is used to collect all the brightness counts for a star.|
Choose Slice to see a profile of the brightness counts along a line and to measure
distance in pixels.
Go to the menu and choose . Move your cursor to the image. Click the mouse and drag across an area to make a line.
(When the slice plot pops up, you may need to click on the title bar and drag the window to the side.) Click on the graph itself and drag your mouse along the plot. Watch the little box on the slice in the image move as your cursor moves across the graph.
|Flip||Go to and select . Select vertical or horizontal and then click OK. Often, the optics of a telescope create an image which is upside down or reversed. You may wish to flip an image to make it match a drawing or photo in a book.|
|Find||Go to and select . In the pop up window, replace the 4 with a number like 20. Click OK. If too many stars are found, choose a higher number. Use Find to collect position and brightness data about many stars all at once.|
Download images to practice tools.
*Tool Notes* *Crab Nebula*
* HOU Explorations *