docs/source/tutorials/03-cutting-out-tpfs-from-tess-ffis.ipynb

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    "# How to cut out Target Pixel Files from Kepler Superstamps or TESS FFIs?\n",
    "\n",
    "You can use `lightkurve` to cut Target Pixel Files (TPFs) out of a series of standard astronomical images, such as [K2 Superstamp Mosaics](https://archive.stsci.edu/prepds/k2superstamp/) or TESS Full-Frame-Images (FFIs).\n",
    "This brief tutorial will demonstrate how!"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Let's assume you have downloaded a set [simulated TESS FFI images](http://archive.stsci.edu/tess/ete-6.html) to a local directory called `data`. `lightkurve` will assume that the files are given in *time order*. So we'll sort the filenames first:"
   ]
  },
  {
   "cell_type": "code",
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   "source": [
    "from glob import glob\n",
    "import numpy as np"
   ]
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   "source": [
    "Now we use the `KeplerTargetPixelFile` class and its function `from_fits_images()` to create the new TPF. This will cut out around the position keyword. You can pass a pixel position in units of the original image or RA and Dec coordinates."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from lightkurve import KeplerTargetPixelFile\n",
    "from astropy.coordinates import SkyCoord"
   ]
  },
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   "cell_type": "markdown",
   "metadata": {
    "scrolled": false
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   "source": [
    "```python\n",
    "fnames = np.sort(glob('data/*.fits'))\n",
    "tpf = KeplerTargetPixelFile.from_fits_images(images=fnames, \n",
    "                                             position=SkyCoord(257.13700, 24.48958, unit='deg'), \n",
    "                                             size=(9,9),\n",
    "                                             target_id='MyCutOut')\n",
    "```"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We then have a fully functioning `KeplerTargetPixelFile` object!  You can read more about such objects in the [tutorial on their use](https://docs.lightkurve.org/tutorials/1.02-target-pixel-files.html)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%matplotlib inline\n",
    "#tpf.plot();"
   ]
  }
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