diff --git a/Lab_2/Lab_2.ipynb b/Lab_2/Lab_2.ipynb
index 9a3a664..e98a0ed 100644
--- a/Lab_2/Lab_2.ipynb
+++ b/Lab_2/Lab_2.ipynb
@@ -4,14 +4,14 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# <p style=\"text-align: center;\">PHYS 134L Spring 2022 Lab 2</p>"
+    "# <p style=\"text-align: center;\">PHYS 134L Spring 2024 Lab 2</p>"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "<div class=\"alert alert-block alert-danger\"><b>Due date:</b> Sunday, April 17th, 2022 by 11:59pm, submitted through Gradescope.</div>"
+    "<div class=\"alert alert-block alert-danger\"><b>Due date:</b> Sunday, April 21th, 2024 by 11:59pm, submitted through Gradescope.</div>"
    ]
   },
   {
@@ -92,7 +92,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "**On a sheet of paper, sketch a map of the part of the sky where the image was taken large enough to include a couple of bright, named stars (please label them).  Check out the [Stellarium website](https://stellarium-web.org/) if you need some help. Note that RA is defined so that as the Earth turns, the RA of objects on the meridian increases with time. Draw your map with N up and E to the left (as it would appear if you were facing the southern horizon). Attach the drawing to the end of this lab report before you submit it to gradescope**"
+    "**On a sheet of paper, sketch a map of the part of the sky where the image was taken large enough to include a couple of bright, named stars (please label them).  Check out the [Stellarium website](https://stellarium-web.org/) if you need some help. Note that RA is defined so that as the Earth turns, the RA of objects on the meridian increases with time. Draw your map with N up and E to the left (as it would appear if you were facing the southern horizon). Attach the drawing to the end of this lab report before you submit it to gradescope.**"
    ]
   },
   {
@@ -130,7 +130,7 @@
    "source": [
     "The word ''sidereal'' means ''with respect to the stars.'' The current Local Sidereal Time (LST) is the value of the RA in the equatorial\n",
     "coordinate system that is crossing your meridian at the moment. Since the coordinates of stars are essentially constant over very long times,\n",
-    "at a given LST you will always find the stars in the same apparent positions in the sky. Sidereal time is not the same as solar time (which we normally use) -- at a given solar time (such as noon), we find the {\\it Sun} in the same position, not the stars. Because the Earth orbits the Sun once per year, the sidereal day is about 4 minutes shorter than the solar day. Thus, measuring by solar time, a given star rises and sets about 4 minutes earlier every day."
+    "at a given LST you will always find the stars in the same apparent positions in the sky. Sidereal time is not the same as solar time (which we normally use) -- at a given solar time (such as noon), we find the _Sun_ in the same position, not the stars. Because the Earth orbits the Sun once per year, the sidereal day is about 4 minutes shorter than the solar day. Thus, measuring by solar time, a given star rises and sets about 4 minutes earlier every day."
    ]
   },
   {
@@ -511,7 +511,7 @@
    "metadata": {},
    "source": [
     "The size of an astronomical image on the CCD detector depends on the effective focal length (usually abbreviated ''focal length'') of\n",
-    "the telescope. Here is a link to a quick primary on focal length: [Focal length and f/# explained](https://www.paragon-press.com/lens/lenchart.html). This part of the lab will use a fits file called ```cluster.fits``` that should have been downloaded to your JupyterHub account when you clicked the link for this notebook, but it can also be found on the Lab 2 tab on the Gauchospace site. "
+    "the telescope. Here is a link to a quick primary on focal length: [Focal length and f/# explained](https://www.paragon-press.com/lens/lenchart.html). This part of the lab will use a fits file called ```cluster.fits``` that should have been downloaded to your JupyterHub account when you clicked the link for this notebook, but it can also be found on the Lab 2 tab on the Canvas site. "
    ]
   },
   {
@@ -641,19 +641,33 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Now open a browser and go to [http://www.sky-map.org](http://www.sky-map.org). This is a nice piece of planetarium software (similar to the Stellarium page we used earlier). Go to ''Home,'' and enter the name of the cluster in the ''Find Object'' window. When the map comes up, point to the small elliptical icon in the upper left called ``DSS,'' and\n",
-    "select ``DSS2 All Sky Survey.'' These data come from various releases of the [Digital Sky Survey](https://irsa.ipac.caltech.edu/data/DSS/). Zoom in 3 or 4 clicks on the size scale, and you should see a familiar star cluster (a bit off center). Drag it\n",
-    "to the center of the window, and zoom it to whatever degree makes you comfortable. Now when you drag the cursor over a star image you\n",
-    "will see lots of information about each star, including a long catalog number, and (most importantly) the star’s equatorial coordinates."
+    "Now open a browser and go to the [Aladin Lite](https://aladin.cds.unistra.fr/AladinLite/) online tool. This is a nice professional tool that contains a little more astronomical data than Stellarium. From it's website: \"Aladin is an interactive sky atlas allowing the user to visualize digitized astronomical images or full surveys, superimpose entries from astronomical catalogues or databases...\". The website provides a simple interface to access some of Aladin's most basic features. If you'd like to explore the tool more I recommend downloading the desktop version. \n",
+    "\n",
+    "**In the search bar enter the name of the cluster pictured above and zoom in. Underneath the search bar there is a selection of different Astronomical image Catalogs that you can display. Select 5 different catalogs and do some internet sleuthing to find out about them. For each catalog find out: At what telescope were these data taken? What is the wavelength of the data being displayed? When was the data taken (or published)?**\n",
+    "\n"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Identify the 4 numbered stars in the image above on the ```sky-map.org``` site, and list their RA, $\\delta$ values in the table below, 1 row per star. Also measure the $\\{x,y\\}$ coordinates\n",
-    "of each star on ```cluster.fits```, using the cursor to pick out the brightest point in each star. Do this carefully, zooming so that setting the cursor is\n",
-    "easy, and adjusting the ``scale'' options so you can easily see the brightness variations inside the star images.  Make a subjective guess about the error (in pixel units) with which you can measure the star positions. Put this in the table too, under error\\_g."
+    "*Your answer here*"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "On the right-hand side of the screen you'll see the option to display data from several different catalogs. When you select one (it may take a second for the data to load), each star in the image that is in that database will show up with a symbol on it. If you click on that symbol you will be shown some of the main identifying information about that star. For the purposes of this lab using the SIMBAD catalog is probably most appropriate. "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "**Identify the 4 numbered stars in the image above on the Aladin Lite site, and list their RA, $\\delta$ values in the table below, 1 row per star. Also measure the $\\{x,y\\}$ coordinates\n",
+    "of each star on ```cluster.fits``` in DS9, using the cursor to pick out the brightest point in each star. Do this carefully, zooming so that setting the cursor is\n",
+    "easy, and adjusting the ''scale'' options so you can easily see the brightness variations inside the star images.  Make a subjective guess about the error (in pixel units) with which you can measure the star positions. Put this in the table too, under _error\\_g_.**"
    ]
   },
   {
@@ -673,7 +687,7 @@
    "metadata": {},
    "source": [
     "What do you think is your largest source of error (the one that dominates your estimate of\n",
-    "error g)?"
+    "error\\_g)?"
    ]
   },
   {
@@ -688,8 +702,8 @@
    "metadata": {},
    "source": [
     "Now compute the distances between various pairs of stars, as given below. Do this first by using the difference in RA and d that you obtained\n",
-    "from ```sky-map.org```. Formally this is an exercise in spherical trigonometry, but because all of these stars are very close together on the sky, we\n",
-    "may use small-angle approximations. In this case we get sufficient accuracy by taking}\n",
+    "from Aladin. Formally this is an exercise in spherical trigonometry, but because all of these stars are very close together on the sky, we\n",
+    "may use small-angle approximations. In this case we get sufficient accuracy by taking\n",
     "$$\n",
     "\\Delta r = \\sqrt{(\\Delta \\delta)^2 + \\left(\\Delta {\\rm RA} \\cos \\delta \\right)^2},\n",
     "$$\n",
@@ -719,7 +733,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "**Also compute the separation between these pairs of stars in units of pixels, using your measured values of $x$ position and $y$ position. In this case the\n",
+    "**Now compute the separation between these pairs of stars in units of pixels, using your measured values of $x$ position and $y$ position. In this case the\n",
     "normal Pythagorean law may be used, with no $\\cos(\\delta)$ factor. (Think about why.) Use your estimates of error\\_g and standard propagation-of-error\n",
     "rules (see the textbook by ***Taylor*** linked on the Lab 2 tab in Gauchospace for a refresher) to estimate the errors in these separations which we will call error $_p$. In the space below, show the formula(s) you used for calculating the error $_p$ values. Then put all of the data into the table below. Expand the number of rows as necessary.**"
    ]
@@ -742,7 +756,7 @@
    "metadata": {},
    "source": [
     "**For each star pair, compute the image scale $\\Delta r/\\Delta p$ in units of arcsec/pixel, and enter this value in the table. Use Taylor’s error propagation rules, starting from your estimates of error $_p$, to estimate the error in your derived value for the image scale (which we will call error $_s$).\n",
-    "Assume that the star separations derived from ```www.sky-map.org``` positions have negligible errors. Put your error $_s$ values in the table.**\n"
+    "Assume that the star separations derived from Aladin positions have negligible errors. Put your error $_s$ values in the table.**\n"
    ]
   },
   {
@@ -776,11 +790,6 @@
    "source": [
     "*You answer here*"
    ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
   }
  ],
  "metadata": {