remove exercises

Author: adrn

tutorials/notebooks/astropy-coordinates/2-Coordinates-Transforms.ipynb

@@ -468,15 +468,6 @@
     "As we hoped and expected, in the Galactic coordinate frame, the open clusters predominantly appear at low galactic latitudes!"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "### Exercises\n",
-    "\n",
-    "TODO"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -679,15 +670,6 @@
     "From this, we can see that only two of the clusters in this batch seem to be easily observable."
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "### Exercises\n",
-    "\n",
-    "TODO"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},

tutorials/notebooks/astropy-coordinates/3-Coordinates-Velocities.ipynb

@@ -448,44 +448,6 @@
     "The red circle is the same as in the previous image and shows the position of the source in the *Gaia* catalog (in 2015.5). The blue circle shows our prediction for the position of the source in 1950 - this looks much closer to where the star is in the DSS image!"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "### Exercises"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "TODO: old exercise below"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "The *Gaia* data table we downloaded for sources around NGC 188 also contains proper motion information. Do any of the sources in the field around NGC 188 have large enough proper motions that we might detect a difference between the DSS position of a star and the *Gaia* position? How many stars have an apparent change in position > 5 arcsec over 60 years?"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# ngc188_pm = np.sqrt(table['pmra']**2 + table['pmdec']**2)\n",
-    "# ((ngc188_pm * 60*u.year) > 5*u.arcsec).sum()"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "Download a DSS image for the region around the fastest-moving star in the NGC 188 field. By accounting for the proper motion, can you predict where the star is in the DSS image using only the *Gaia* position and proper motion?"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},

tutorials/notebooks/astropy-coordinates/4-Coordinates-Crossmatch.ipynb

@@ -10,7 +10,8 @@
     "Adrian Price-Whelan\n",
     "\n",
     "## Learning Goals\n",
-    "* TODO\n",
+    "* Demonstrate how to retrieve a catalog from Vizier using astroquery\n",
+    "* Show how to perform positional cross-matches between catalogs of sky coordinates\n",
     "\n",
     "## Keywords\n",
     "coordinates, OOP, astroquery, gaia\n",
@@ -354,113 +355,6 @@
     "For more on what matching options are available, check out the [separation and matching section of the Astropy documentation](https://astropy.readthedocs.io/en/stable/coordinates/matchsep.html). Or for more on what you can do with `SkyCoord`, see [its API documentation](http://astropy.readthedocs.org/en/stable/api/astropy.coordinates.SkyCoord.html)."
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "### Exercises"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "TODO - update exercises!"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "Using the coordinates of the center of the Pleiades you defined in the previous set of exercises, download a catalog of 2MASS sources within 1 degree of the center of the Pleiades. Make a color-magnitude diagram of J-H vs. J for all sources. Can you see the main sequence corresponding to the Pleiades?"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# v = Vizier(catalog=\"II/246\")  \n",
-    "# v.ROW_LIMIT = -1\n",
-    "\n",
-    "# result = v.query_region(pleiades_center, radius=1*u.deg)\n",
-    "# tmass_table_pleiades = result[0]"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# Jmag_p = tmass_table_pleiades['Jmag']\n",
-    "# Hmag_p = tmass_table_pleiades['Hmag']\n",
-    "\n",
-    "# plt.scatter(Jmag_p - Hmag_p, Jmag_p,\n",
-    "#             marker='o', color='k', \n",
-    "#             linewidth=0, alpha=0.5)\n",
-    "# plt.xlim(-0.4, 0.75)\n",
-    "# plt.ylim(12, 2)"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "Again using the coordinates of the center of the Pleiades, now download all *Gaia* sources within 1 degree of the center of the Pleiades. Cross-match the 2MASS and *Gaia* sources, and make a G-J vs. G color-magnitude diagram of all sources within 200 parsecs of the Sun."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# Gaia.ROW_LIMIT = 10_000\n",
-    "# job = Gaia.cone_search_async(pleiades_center, radius=1*u.deg)\n",
-    "# gaia_table_pleiades = job.get_results()\n",
-    "\n",
-    "# # This might produce a bunch of warnings: you can ignore these!\n",
-    "# gaia_table_pleiades = QTable(gaia_table_pleiades[gaia_table_pleiades['parallax'] > 0])"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# tmass_ple_coords = SkyCoord(tmass_table_pleiades['RAJ2000'],\n",
-    "#                             tmass_table_pleiades['DEJ2000'])\n",
-    "\n",
-    "# gaia_ple_coords = SkyCoord(gaia_table_pleiades['ra'],\n",
-    "#                            gaia_table_pleiades['dec'],\n",
-    "#                            Distance(parallax=gaia_table_pleiades['parallax']))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# idx_ple, d2d_ple, _ = gaia_ple_coords.match_to_catalog_sky(tmass_ple_coords)\n",
-    "\n",
-    "# sep_mask = (d2d_ple < 2*u.arcsec) & (gaia_ple_coords.distance < 200*u.pc)\n",
-    "\n",
-    "# Gmag_ple = gaia_table_pleiades[sep_mask]['phot_g_mean_mag']\n",
-    "# Jmag_ple = tmass_table_pleiades[idx_ple[sep_mask]]['Jmag']\n",
-    "\n",
-    "# plt.scatter(Gmag_ple - Jmag_ple, Gmag_ple, \n",
-    "#             marker='o', color='k', \n",
-    "#             linewidth=0, alpha=0.5)\n",
-    "# plt.xlabel('$G - J$')\n",
-    "# plt.ylabel('$G$')\n",
-    "# plt.xlim(-1, 3.5)\n",
-    "# plt.ylim(19, 0)  # backwards because magnitudes!"
-   ]
-  },
   {
    "cell_type": "code",
    "execution_count": null,