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Examples
Optical lightcurve of (20000) VarunaThis example demonstrates a data reduction process in which the optical lightcurve of the fastly rotating trans-Neptunian object (TNO), (20000) Varuna has been measured.
A composite image of M74In this example we demonstrate how the tasks in the FITSH package can be exploited to create a color composite astronomical image from individual scientific frames. In principle, a nice colorful image requires low noise, so either we need long exposure frames or multiple images should be combined in order to obtain this sufficiently low noise level. Since both the guiding errors of the telescope mounts and the presence of the athmospheric refraction impede us from longer exposure times, we focus on now methods based on multiple image combination. Additionally, this method also has the advantage that small but explicit dithering in the telescope position allows us to reject bad pixels or flat errors from the final image by taking a median average of the individual frames.
AstrometryHere we demonstrate how the astrometry of a target object can be done using the tasks of the FITSH package. This example relates to the example shown above, regarding to the optical photometry of Varuna.
Analysis of transiting extrasolar planetsIn this example, we demonstrate how the FITSH task can be used to completely reduce a data series acquired for a transit of the extrasolar planet HAT-P-13b. These observations were made on the night of 2010 December 27/28, between 23:21 and 04:28 UT using the 60/90/180 cm Schmidt telescope located on the Piszkés-tető Mountain Station of the Konkoly Observatory, Hungary. The nominal length of the transit of this planet is approximately 3.5 hours, and this series of observations were almost scheduled for the predicted mid-transit time, 01:49 UT (using the available ephemerides at that time). All in all, 460 individual frames were taken with a net exposure time of 20 seconds, thus one cycle was approximately 42 seconds (i.e. adding the 22 seconds of overhead yielded by the camera readout). See the paper Transit timing variations in the HAT-P-13 planetary system for more details about the physics of this planetary system (and where these measurements have been published shortly after this observation).
Implementation of the IMEXAM featuresAlthough one of the primary design concepts of the FITSH package was to provide a robust set of command-line driven utilites and to provide a shell-hosted environment for massive batched image processing; the individual FITSH tasks can be exploited easily to create interactive applications as well. In this example we show how the tasks firandom, fiphot and lfit can be used to implement the well-known IRAF task, imexamine (that is usually referred as simply as imexam).
Isotropic and anisotropic pointing modelsThis example demonstrates how a simple construction can be given in order to create isotropic and anisotropic telescope pointing models. This practical example evaluates and expects a series of four-column data containing instrumental and celestial hour angle - declination coordinates. Note that the full mathematical description is available in the paper TBD, this example above focuses only on the practical implementation of the pointing model evaluation.
Available supporting data and archives
The table below shows the list of available data archives that are supporing materials for some of the examples. Files are available via both FTP and HTTP. Browse the FTP directory for the individual files or directories and use your favourite FTP client to download these. In addition, you can retrieve a list of individual files that can be downloaded via HTTP either by hand or by utilities that support batched downloading from a list file (see e.g. the wget utility and its -i or --input-file command line argument that can directly be used to pass these list files). Alternatively, the full archives can be downloaded as a single tar file (that are not compressed due to the low relative yield of compressing calibrated FITS images). Note that if the example files are downloaded individually, ensure the hierarchy after the downloading in order to be ready for processing by the example scripts (e.g. put the FITS files into the directory ./fits and so on, see also the related example descriptions). The TAR files contains the necessary subdirectory structures, so these have only to be extracted.
Example FTP directory List of files (HTTP) Full, ordered archive in TAR format Archive size Analysis of transiting extrasolar planets /share/hatp13-20101227 hatp13-20101227.list hatp13-20101227.tar 29348.8 Mbytes A composite image of M74 /share/m74-galaxy m74-galaxy.list m74-galaxy.tar 1912.9 Mbytes Optical lightcurve of (20000) Varuna /share/varuna-20101105 varuna-20101105.list varuna-20101105.tar 5677.2 Mbytes Please note that some of the examples have a large amount of supporting data (up to 30 gigabytes), so expect a relatively long download.