Datasets for education and for fun
On the data pages you will find some sets of image files taken of astronomical objects.
Each dataset contains:
- FITS files of the astronomical object taken through different wavelength filters. The name of the file gives an indication of the filter used.
- Composite 16 bit and 8 bit colour image in Photoshop (.psd) format that contains the original exposures in different coloured layers. The 8 bit formats are mainly for users of Photoshop 7.0 and Elements 2.0. The separate layers allow separate manipulation of the individual exposures. The images were imported into Photoshop with the help of the ESA/ESO/NASA FITS Liberator.
Note: these psd-files should not in any way be considered the end-product of what can be done with image processing. We simply supply them for your convenience in the unlikely event that you should experience problems using the ESA/ESO/NASA FITS Liberator :-)
- A link to any original news releases where more astronomical information about the object can be found.
- The Eagle Nebula
- The Star Forming Nebula - Messier 17
- The Proto Planetary Nebula - Roberts 22
- The Planetary Nebula NGC 5307
- The Planetary Nebula NGC 6309 - Box Nebula
- The Planetary Nebula NGC 6881
- Ultraviolet Venus
- The Galaxy NGC 1068
- The star-forming region N11B
- The Planetary Nebula NGC 6302 - Bug Nebula
- The Dwarf Galaxy NGC 1569
- The Globular Cluster Messier 12
- The Globular Cluster NGC 6652
- The Galaxy Messier 31
- The Open Cluster Messier 35
- The Orion Nebula Messier 42
- The colliding Antennae Galaxies
Archives with astronomical data
- The ESO/ST-ECF Science Data Archive
- Go to "On-line User Registration"
- Fill in the form (do not worry too much about the "Storage medium issues"
- When you receive your login and password, go to the archive you want data from). Let's take the case of the Hubble Archive.
- Type the name of the object you would like data from in the "Target" field, or type the coordinates (re, dec) if you have them. For instance M 42.
- Choose the instrument you would like data from, for instance WFPC2.
- Check the exposures you want.
- Click "Request marked Datasets"
- Type login/password.
- Select "HST associated products: NICMOS CalnicB, WFPC2 imshift + imcombine: if possible
- Select "FTP"
- Press submit
- You will now receive an email stating you have submitted a request.
- After a few hours the data will have been retrieved from the archive and calibrated with the most recent algoritms and ready for you to download via the Internet (ftp in a web browser).
- Choose only files with the following endings (see the documentation here if necessary):
- Images from the WFPC2 camera are made out of four seperate exposures from the four CCD chips. They are layered in so-called "planes". In the FITS Liberator you have to import each plane at a time and stitch them together manually.
- If you plan to use WFPC2 images for very high-level products such as press release images, it is recommended to use an automated task to combine the 4 individual WFPC2 images. We use IRAF's Wmosaic task. It corrects for geometric distortion (the camera is not exactly aligned with Hubble's optical axis) and rotates, offsets and scales the individual images to produce one large mosaic image. Furthermore the task dues a pretty good job of 'stitching' together the edges (not perfect, but better than by hand).
- Type the name of an object in "Object Name:", e.g. M 42
- Choose image size, measure in arc-minutes or 1/60 degree. E.g. 5 x 5.
- Choose Survey, e.g. "DSS-2-blue"
- Choose output format, e.g. "Display as GIF", or "Download as FITS file".
- Repeat for other filters to collect three different colours
- Read the FITS files into Photoshop with the help of FITS Liberator.
- Combine them to a colour image
- Align the images. "DSS-2-Red" images normally need scaling. Try 101.15%.
- STScI's Data Archive
- Vizier archive of astronomical catalogues