![]() – in other words it does not need to know anything in advance about the location, orientation or image scale to calibrate an image. Plate Solving with Īis plate solving software but unlike Maxim-DL and Astroart it performs ‘blind astrometry’ on a FITS or jpeg image. Also, both Maxim DL and Astroart are not cheap – and are likely to be of interest only to imaging astronomers.Īn alternative is to use. Some commonly used image acquisition tools such as Maxim DL and Astroart include a plate solving function – these are effective but require more than a few hints about image scale and the approximate location in the sky of the area imaged. ![]() Plate solving consists of using star pattern matching against a given stellar catalogue to calculate the coordinates of the centre of an image. There are a number of ways to perform astrometric calibration – or plate solving as it is usually called (a hangover from the days of photographic plates). A calibrated FITS image header holds information on location in the sky and image orientation this information is held in WCS (world co-ordinate system) format. A major feature of the FITS format is that data about the image is stored in a human readable ASCII header. To use Aladin with your own images (or an image acquired from the Internet) you need to first perform an astrometric calibration to create a calibrated image in FITS format. This is where Aladin really comes into its own. However, for astronomers who spend their nights acquiring beautiful deep-sky images Aladin enables these to be combined with scientific data acquired by the large ground based and space observatories. SIMBAD data for the Crab Nebula progenitor pulsar (click to enlarge)Īladin gives unprecedented access to contextualised multi-wavelength data and is a valuable tool for any amateur astronomer looking to understand more about the universe. With Aladin you can select individual data points and drill down into the data itself to view data such as distances, spectra, proper motions, etc. Crab Nebula visualised using Aladin and showing reference points and proper motions (click to enlarge) In just a few clicks you can access and download related datasets and information from many sources including the SIMBAD database, the VizieR service and many other astronomy data archives. Visualising multi-wavelength data by superimposing entries from astronomical catalogues or databases.Visualising digitized astronomical images. ![]() With Aladin you can perform tasks such as: It is available to download as Java program which can be run as stand-alone software on the PC, or as a java applet which will run in your Internet browser. Aladin was developed and maintained by the Centre de Données Astronomiques de Strasbourg (CDS) and is one of several tools that comprise the European Virtual Observatory (VO) toolset. The Aladin Sky Atlasis perhaps the most exciting and useful tool for the amateur astronomer. ![]() In the mean time, there are a number of references and links at the end of this article should you want to find out more. If there is sufficient interest amongst members then perhaps a presentation on this subject can be arranged for a future meeting. The following article presents a brief overview of three of the more interesting tools. I was able to use these with very good effect to complete my assignment. Whilst gathering the information I needed, I came across some powerful yet easy to use Virtual Observatory software tools for the retrieval and analysis astronomy images and data. One of the course assignments required students to research the characteristics of a given peculiar galaxy using astronomical databases and other information sources available on the Internet. I have recently completed an Advanced University Certificate in ‘Astrophysics of Galaxies’, a challenging two-year distance learning course run by the University of Central Lancaster. Print This Post Astrometry Tools and the Aladin Sky Atlas by Peter Campbell-Burns Featured Articles - By Peter Campbell-Burns on Januat 5:39 pm
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