Red-Green-Blue (RGB) Color Composite
Images of the Tarantula Nebula
Select from these images:

Each image is an exposure of 30 seconds taken by Dr. Rhodes Hart with the CDK20S telescope at Mt. Kent Observatory on the night of October 5, 2010, UT. The filters are Johnson-Cousins B (375 to 390 nm), V (490 to 580 nm), R (570 to 690 nm), and I (725 to 1025 nm). The remnant of SN1987A is out of the field to the lower right.

Click on an image name above to load it into the display. The File menu will show you the images that are loaded. Once loaded, you may select that image by clicking on File. JS9 utilizes a single mouse button for user interaction. Keyboard input also is minimized. Moving the mouse (or a single finger on the iPad) over the image will display the position/value of individual pixels. Pressing and moving the mouse (or two fingers) will change the contrast and bias of the image. A double-click or long-press inside a region will bring up the configuration menu for that region.

Use View and Panner to explore the entire image.

You can display each image separately and assign to them one of the red, green, or blue colormaps. If you then select the menu option Color->rgbMode, they will be displayed as one RGB composite image. The current image (as shown in the File menu) determines which of the three independent colormaps is changed by contrast/bias mouse manipulation. To remove an image from the RGB composite, give it a different colormap. Re-join (or add a new image) by assigning one of the RGB colormaps. Turn off rgbMode to display the images separately.