Multiple ephemerides for RR Lyrae

README.md

@@ -6,18 +6,29 @@ Demo notebooks for [lcviz](https://github.com/spacetelescope/lcviz).  These note
 
 ## Plugins
 
+#### Plot Options
+
+* [RR-Lyrae](mult_ephem_RR-Lyr.ipynb)
+
 #### Flattening
 
 * [KIC 2835289](mult_ephem_kic_2835289.ipynb)
 
+#### Frequency Analysis
+
+* [RR-Lyrae](mult_ephem_RR-Lyr.ipynb)
 
 #### Ephemeris / Phase-Folding
 
 * [KIC 2835289](mult_ephem_kic_2835289.ipynb)
-
+* [RR-Lyrae](mult_ephem_RR-Lyr.ipynb)
 
 ## Science Topics
 
 #### Eclipsing Binaries
 
 * [KIC 2835289](mult_ephem_kic_2835289.ipynb)
+
+#### Pulsating Stars
+
+* [RR-Lyrae](mult_ephem_RR-Lyr.ipynb)

mult_ephem_RR-Lyr.ipynb

@@ -0,0 +1,184 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "c0bbfab2-238f-4539-9a51-d6cb46fc067d",
+   "metadata": {},
+   "source": [
+    "# RR Lyrae\n",
+    "\n",
+    "[RR Lyrae](https://en.wikipedia.org/wiki/RR_Lyrae) is the prototype of a class of variable stars with radial pulsations. The pulsation period is related to the stellar luminosity, and a second, lower frequency variation can be seen on longer timescales, known as the [Blazkho effect](https://en.wikipedia.org/wiki/Blazhko_effect). \n",
+    "\n",
+    "* **Last Updated**: Dec 6, 2023\n",
+    "* **lcviz version**: unreleased (Dec 6, 2023)\n",
+    "\n",
+    "RR Lyrae itself was in the Kepler field, so let's load one Kepler Quarter of long-cadence observations, and inspect the periods:"
+   ]
+  },
+  {
+   "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 long cadence observations from Kepler:\n",
+    "lc = search_lightcurve(\n",
+    "    target=\"RR Lyra\", \n",
+    "    mission=\"Kepler\", \n",
+    "    quarter=2, \n",
+    "    cadence=\"long\", \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": "96da5408-26ab-4823-b85f-4a1992c1c7dc",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "lcviz = LCviz()\n",
+    "\n",
+    "lcviz.load_data(lc)\n",
+    "\n",
+    "# we'll make use of these plugins later:\n",
+    "eph = lcviz.plugins['Ephemeris']\n",
+    "plot_options = lcviz.plugins['Plot Options']\n",
+    "freq_analysis = lcviz.plugins['Frequency Analysis']\n",
+    "freq_analysis.auto_range = False\n",
+    "freq_analysis.xunit.selected = 'period'\n",
+    "\n",
+    "lcviz.show()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "ab983eb0-6da0-45ee-a343-edfa1155f384",
+   "metadata": {},
+   "source": [
+    "Compute the peak power at periods near 13 hours using the `Frequency Analysis` plugin, and use the `Ephemeris` plugin to add a new viewer that's phase-folded at the pulsation period:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "17261527-c741-4cc7-a08c-4df10a9daef6",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "# compute pulsation period:\n",
+    "freq_analysis.minimum = 0.1\n",
+    "freq_analysis.maximum = 1.0\n",
+    "ls = freq_analysis.periodogram\n",
+    "period_pulsation = 1 / ls.frequency[ls.power.argmax()]\n",
+    "\n",
+    "# update Ephemeris:\n",
+    "eph.rename_component('default', 'pulsation')\n",
+    "eph.period = period_pulsation.to_value(u.d)\n",
+    "eph.t0 = 0.26\n",
+    "\n",
+    "print(f\"Pulsation period: {period_pulsation:.3f}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "d0132512-d62e-45bb-9b25-61d9e3664f45",
+   "metadata": {},
+   "source": [
+    "Compute the peak power at periods near 36 days using the `Frequency Analysis` plugin, and add an `Ephemeris` component for the Blazkho effect:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "2bcb8d93-e9d0-4219-9539-d797099a172d",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "# compute Blazkho period:\n",
+    "freq_analysis.minimum = 20.0\n",
+    "freq_analysis.maximum = 55.0\n",
+    "ls = freq_analysis.periodogram\n",
+    "period_blazkho = 1 / ls.frequency[ls.power.argmax()]\n",
+    "\n",
+    "# update Ephemeris:\n",
+    "eph.add_component('blazkho')\n",
+    "eph.period = period_blazkho.to_value(u.d)\n",
+    "eph.t0 = 23\n",
+    "\n",
+    "print(f\"Blazkho period: {period_blazkho:.3f}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "087ffb91-d24e-49e7-ba9a-14c6df0510ce",
+   "metadata": {},
+   "source": [
+    "Color each point in the light curve in each viewer by the phase of the Blazkho effect, using the `Plot Options` plugin:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "39108e3e-b84c-4c21-9861-007f3a0ab2da",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "for viewer in lcviz.app.get_viewer_reference_names():\n",
+    "    plot_options.viewer = viewer\n",
+    "    plot_options.layer = lcviz.app.data_collection[0].label\n",
+    "    plot_options.marker_color_mode = 'Linear'\n",
+    "    plot_options.marker_colormap = 'Viridis'\n",
+    "    plot_options._obj.marker_color_col_value = 'phase:blazkho'"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.11.4"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}