HAT-P-7 b short cadence example

notebooks/example_HAT-P-7b.ipynb

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+   "id": "c0bbfab2-238f-4539-9a51-d6cb46fc067d",
+   "metadata": {},
+   "source": [
+    "# Short cadence observations of HAT-P-7 b\n",
+    "\n",
+    "HAT-P-7 b ([Pál et al. 2008](https://ui.adsabs.harvard.edu/abs/2008ApJ...680.1450P/abstract)) is a hot Jupiter orbiting a bright F6V host in the Kepler field. Let's take a look at short cadence (one-minute) Kepler observations from the first three Kepler quarters to see the secondary eclipse of the planet, when the planet's flux disappears as the planet is eclipsed by the host star.\n",
+    "\n",
+    "First we download the observations with `lightkurve`:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "3c6f5e23-f9d9-4577-b012-4f138f722e9a",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "import astropy.units as u\n",
+    "from astropy.time import Time\n",
+    "from lightkurve import search_lightcurve\n",
+    "\n",
+    "from lcviz import LCviz\n",
+    "\n",
+    "# Download three quarters of short cadence observations from Kepler:\n",
+    "lc = search_lightcurve(\n",
+    "    target=\"HAT-P-7\", \n",
+    "    mission=\"Kepler\", \n",
+    "    quarter=[1, 2, 3], \n",
+    "    cadence=\"short\", \n",
+    "    author=\"Kepler\"\n",
+    ").download_all().stitch(\n",
+    "    # stitch together the quarters after normalizing each one:\n",
+    "    lambda x: x.normalize()\n",
+    ")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "74d491b0-b59f-43bb-b24b-ba530d1185bb",
+   "metadata": {},
+   "source": [
+    "Now we'll start `LCviz`:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "17261527-c741-4cc7-a08c-4df10a9daef6",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "lcviz = LCviz()\n",
+    "lcviz.show()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "210a6609-1a6c-42d0-81e3-696492a79e11",
+   "metadata": {},
+   "source": [
+    "Now load the data. This takes a moment because there are nearly 300,000 observations in the light curve:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "81ace88e-9d18-4b81-9634-cfbfac8983ce",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "lcviz.load_data(lc)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "46809b2d-1ef3-4eb6-9b13-69e91469e5ee",
+   "metadata": {},
+   "source": [
+    "Now let's phase-fold the observations with the ephemeris of the planet using the `Ephemeris` plugin:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "2eec0609-f242-41d0-bc06-4a28177d541f",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "# planet parameters from Morris et al. 2013:\n",
+    "# https://ui.adsabs.harvard.edu/abs/2013ApJ...764L..22M/abstract\n",
+    "\n",
+    "time_coordinates = lcviz.app.data_collection[0].coords\n",
+    "reference_time = time_coordinates.reference_time\n",
+    "\n",
+    "period = 2.204737  # days\n",
+    "epoch = Time(2454954.357463, format='jd')\n",
+    "\n",
+    "# phase-fold the transit light curve in an ephemeris viewer:\n",
+    "eph = lcviz.plugins['Ephemeris']\n",
+    "eph.period = period\n",
+    "eph.t0 = (\n",
+    "    (epoch - reference_time).to_value(time_coordinates.unit) % eph.period\n",
+    ")\n",
+    "\n",
+    "# offset the wrapping phase so the transit (at phase 0) displays at center\n",
+    "eph.wrap_at = 1"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "c9b2bfe4-6b36-4fc6-bced-fb6062c35cf2",
+   "metadata": {},
+   "source": [
+    "We can easily see the secondary eclipse if we bin the phased observations with the `Binning` plugin, and adjust the axes:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "0d97cbfa-162b-4204-80ec-fbe0c6dc8fab",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "binning = lcviz.plugins['Binning']\n",
+    "binning.n_bins = 150\n",
+    "binning.keep_active = True\n",
+    "binning.ephemeris = 'default'\n",
+    "\n",
+    "viewer = lcviz.app.get_viewer('flux-vs-phase:default')\n",
+    "viewer.state.y_min = 0.9995\n",
+    "viewer.state.y_max = 1.0005"
+   ]
+  }
+ ],
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