SSW2022 Activities - Revision history

Rebull at 02:08, 4 June 2024

2024-06-04T02:08:48Z

Rebull at 16:42, 6 October 2022

2022-10-06T16:42:33Z

Rebull at 23:57, 5 October 2022

2022-10-05T23:57:21Z

Rebull at 23:40, 5 October 2022

2022-10-05T23:40:54Z

Rebull at 23:39, 5 October 2022

2022-10-05T23:39:30Z

Rebull at 23:38, 5 October 2022

2022-10-05T23:38:27Z

Rebull at 23:26, 5 October 2022

2022-10-05T23:26:07Z

Rebull at 23:21, 5 October 2022

2022-10-05T23:21:08Z

Rebull at 23:17, 5 October 2022

2022-10-05T23:17:40Z

Rebull at 23:08, 5 October 2022

2022-10-05T23:08:33Z

@@ Line 5: / Line 5: @@
 == Monday Afternoon, Part 1==
-# ''Query the Gaia Catalog of Nearby Stars (GCNS) for all stars within 20 pc.'' - as of the time I am writing this, the GCNS isn't available at IRSA, so you have to either go directly to the [https://gea.esac.esa.int/archive/ ESA Gaia Archive] to get it, or get it from [https://vizier.cds.unistra.fr/viz-bin/VizieR VizieR], like at [https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/649/A6 this ftp site]. The GCNS is '''large''', but you can get it in csv format, which IRSA tools understand. To make this process easier, though, [https://caltech.box.com/s/ohqzfmhzf4ifc46caayh3fsyfpgxsn7p here] is a truncated csv version of this catalog.
+# ''Query the Gaia Catalog of Nearby Stars (GCNS) for all stars within 20 pc.'' - as of the time I am writing this, the GCNS isn't available at IRSA, so you have to either go directly to the [https://gea.esac.esa.int/archive/ ESA Gaia Archive] to get it, or get it from [https://vizier.cds.unistra.fr/viz-bin/VizieR VizieR], like at [https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/649/A6 this ftp site]. The GCNS is '''large''', but you can get it in csv format, which IRSA tools understand. To make this process easier, though, [https://caltech.box.com/s/72dlt4l8547eb3g6nbn0kyh70hx5jeln here] is a truncated csv version of this catalog.
 ##Download and uncompress that copy, or download your own copy from VizieR.
 ##Load that csv catalog into IRSA Viewer by clicking on the catalogs tab, then "Load Catalog File."

← Older revision		Revision as of 16:42, 6 October 2022
Line 104:		Line 104:
	# ''Astrophysical Parameters from Gaia DR3''		# ''Astrophysical Parameters from Gaia DR3''
	##These are not yet available at IRSA, so we are stopping here for the moment.		##These are not yet available at IRSA, so we are stopping here for the moment.
		+
		+
		+	=Relevant topics from the rest of the wiki=
		+	(e.g., these are the "Lego bricks" to go investigate in order to build this "Lego kit.")
		+	*[[Filters]]
		+	*[[Photometry (finding it)]]
		+	*[[Gliese Catalog Explorations]] - things to do with nearby stars
		+	*[[Getting your feet wet with catalogs and plots at IRSA]] - getting started playing with catalogs (tables) and plots

@@ Line 22: / Line 22: @@
 == Monday Afternoon, Part 2==
 {| class="wikitable"
 |-
@@ Line 74: / Line 70: @@
 |}
 # ''Crossmatch the Exoplanet Archive and Gaia DR3''
 ##Load the [https://irsa.ipac.caltech.edu/applications/Gator/ IRSA Catalog Search Tool]

@@ Line 65: / Line 65: @@
 | parallax || Parallax in mas
 |-
-|parallax_over_error || parallax divided by the error in parallax
+|parallax_over_error || parallax divided by the error in parallax, e.g., a measure of signal-to-noise
 |-
 |distance_gspphot || Distance in pc
@@ Line 102: / Line 102: @@
 ##For this, we need to dig into the column definitions of the Gaia DR3 catalog -- see table above. You are going to want to plot on the x-axis B-R-E(B-R) to correct for the reddening, and on the y-axis, G-5logd-5-Ag. For the first request, you can invert the parallax to get the distance (watch your units), and for the second request, use the distance provided in the catalog. Pin the plots to compare them side-by-side.
 ##There are definitely points that are different. Click on points in either plot to find the corresponding rows in the catalog. Do you notice anything about the most discrepant points? The words and the code in the Colab notebook solutions do different things, but one could explore filtering to omit negative parallaxes or those with parallax_over_error < 5.

@@ Line 64: / Line 64: @@
 |-
 | parallax || Parallax in mas
 |-
 |distance_gspphot || Distance in pc

@@ Line 96: / Line 96: @@
 ##What plot did you use? You may be tempted to try sy_gaiamag_01 vs. phot_g_mean_mag but can you find a better one?
 ##You probably have a situation where there are so many points that you only have a heatmap (binned greyscale) plot. How can you filter down the catalog so that you can identify individual objects that may be problematic? (Hint: maybe something somewhere like abs("phot_g_mean_mag"-"sy_gaiamag_01") > 0.1?) Do you notice anything in common about these stars?
-##I note that we do still have the problem where individual planets are listed once but stars are listed more than once (e.g., Kepler 108 appears once for Kepler 108b and once for 108c), but these points should be plotted identically on top of each other in the plots; they just contribute to source counts. If you want to get rid of them, to first order, keep only those that have a "b" in the planet name, e.g., impose a filter "like '%b%'" on pl_name_01. (This actually helps because it weeds down the catalog enough to see individual points!)
+##I note that we do still have the problem where individual planets are listed once but stars are listed more than once (e.g., Kepler 108 appears once for Kepler 108b and once for 108c), but these points should be plotted identically on top of each other in the plots; they just contribute to source counts. If you want to get rid of them, to first order, keep only those that have a "b" in the planet name, e.g., impose a filter "like '%b%'" on pl_name_01. This should omit all the planets that are 'c' or 'd' or 'e' ... you get the idea. It will keep any that have "b" in the root of their name, however. (This actually helps because it weeds down the catalog enough to see individual points!)
 # ''Plot the Gaia absolute CMD diagram for the exoplanet host stars, corrected for the effects of extinction. Make two plots, one using the parallaxes to calculate G and the other using Gaia DR3 distances. What might be the cause of the differences you see? Create a plot to investigate this.''
-##For this, we need to dig into the column definitions of the Gaia DR3 catalog -- see table above. You are going to want to plot on the x-axis B-R-E(B-R) to correct for the reddening, and on the y-axis, G-5logd-5-Ag. For the first request, you can invert the parallax to get the distance (watch your units), and for the second request, use the distance provided in the catalog.
+##For this, we need to dig into the column definitions of the Gaia DR3 catalog -- see table above. You are going to want to plot on the x-axis B-R-E(B-R) to correct for the reddening, and on the y-axis, G-5logd-5-Ag. For the first request, you can invert the parallax to get the distance (watch your units), and for the second request, use the distance provided in the catalog. Pin the plots to compare them side-by-side.

@@ Line 51: / Line 51: @@
 |-
 | st_age || Stellar data / Stellar Age
 |}