The document describes a MySQL database created to analyze observations of 539,825 stars in the Pinwheel Galaxy (M101). The database contains values like position, brightness, and color for each star. A search engine and graphing utility were developed to query and visualize the data. Specific stars were selected for additional analysis as possible Luminous Blue Variables based on their high luminosity. Plots of visual magnitude versus B-V color for stars within 5 arcseconds of each selected star are presented.

1. M101 Database
Eric Pollpeter
AST 4994W
April 23, 2015
Introduction
In order to perform efficient data analysis on a population of 539,825 star observations in galaxy M101 also
known as the Pinwheel Galaxy, a MySQL database was constructed. The database table contains values
for right ascension, declination, visual brightness, B-V, infrared brightness, and field location for each star
observation. In addition, each brightness measurement includes a quoted error value. A search engine that
queries the database and returns observations was created allowing for quick access to data, and a simple
graphing utility was added to give users visual feedback of the results. Users can also download a .csv file
of the data allowing additional analysis to be done with Microsoft Excel, MATLAB, or other programs that
read .csv. The search functions added include the ability to query all stars in a given field, visual or B-V
magnitude range, right ascension and declination range, and search by right ascension and declination center
point and range around that center point.
Method
In order to build the database, the first step was to convert the raw data from a text (.txt) file into a comma
separated value (.csv) file which could be imported into a table using phpMyAdmin. The conversion was
done by using Microsoft Excel’s “convert to columns” function which converted each tab in the .txt file to
an individual cell. Once the conversion was completed, a few extra columns were constructed including an
ID column, and the decimal values for right ascension and declination. The decimal values were necessary
since the original right ascension and declination columns contained colons forcing them to be saved as text
instead of numbers in the database. Querying by a number range is much more convenient than searching
within text.
After the .csv file was constructed, a MySQL database was added to the etacar.umn.edu server using
phpMyAdmin and a table called M101 was added to the new database. The .csv file was imported into the
table and tested to assure proper configuration. A new .php file was added on the server in the M101 folder
at http://etacar.umn.edu/LuminousStars/M101/ and was called database.php. Within this file contains all
the forms and query controllers required to access and collect data from the M101 table based on what the
user inputs into the forms. Once the data is brought back from the database, a script converts all the visual
magnitude and B-V values from the table into a long string of X and Y values which then get passed to the
graphing utility. When the “download .csv” button is pressed, the data table gets passed to the export.php
file which adds commas and separators to the data and prompts the user to save.
Using the search engine and download-able .cvs file features on the website, I was able to collect datasets
of all the stars within 5 arc seconds of the stars shown below. Most of the stars were selected because of their
high luminosities suggesting that they might be good LBV candidates (Luminous Blue Variables). Once all
of the .csv files were downloaded, I created a script in MATLAB to load in the tables and populate all of
the visual magnitude vs. B-V graphs. The central stars are circled in each graph.
1

2. Star ID: 9492 14 11998
αJ 2000 = 14:02:20.98
δJ 2000 = 54:20:04.38
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
Star ID: 9492 14 8847
αJ 2000 = 14:02:27.30
δJ 2000 = 54:19:52.50
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
2

3. Star ID: 9492 14 14450
αJ 2000 = 14:02:28.83
δJ 2000 = 54:20:14.03
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
Star ID: 9490 c2 14120
αJ 2000 = 14:02:48.46
δJ 2000 = 54:19:35.80
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
3

4. Star ID: 9490 02 152
αJ 2000 = 14:02:56.71
δJ 2000 = 54:18:34.09
+/- 5”
−1.5 −1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 a3 10940
αJ 2000 = 14:02:59.37
δJ 2000 = 54:23:23.89
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
4

5. Star ID: 9490 02 991
αJ 2000 = 14:03:01.84
δJ 2000 = 54:19:49.62
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
Star ID: 9490 02 1239
αJ 2000 = 14:03:02.61
δJ 2000 = 54:20:01.38
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
5

6. Star ID: 9490 02 598
αJ 2000 = 14:03:04.70
δJ 2000 = 54:19:25.00
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
Star ID: 9490 a3 14757
αJ 2000 = 14:03:05.13
δJ 2000 = 54:23:42.14
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
6

7. Star ID: 9490 a3 11594
αJ 2000 = 14:03:07.95
δJ 2000 = 54:23:26.81
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
Star ID: 9490 01 6951
αJ 2000 = 14:03:09.19
δJ 2000 = 54:21:38.77
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
28
B−V [mag]
V[mag]
7

8. Star ID: 9490 a2 20839
αJ 2000 = 14:03:11.06
δJ 2000 = 54:18:30.96
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 03 6943
αJ 2000 = 14:03:11.32
δJ 2000 = 54:25:18.55
+/- 5”
−0.5 0 0.5 1 1.5 2
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
8

9. Star ID: 9490 02 1086
αJ 2000 = 14:03:13.44
δJ 2000 = 54:19:54.44
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 02 1340
αJ 2000 = 14:03:13.74
δJ 2000 = 54:20:04.56
+/- 5”
−1 −0.5 0 0.5 1 1.5 2
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
9

10. Star ID: B162
αJ 2000 = 14:03:14.80
δJ 2000 = 54:17:37.93
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: V4
αJ 2000 = 14:03:14.98
δJ 2000 = 54:16:45.26
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
10

11. Star ID: 9490 01 3663
αJ 2000 = 14:03:16.64
δJ 2000 = 54:20:42.04
+/- 5”
−1 −0.5 0 0.5 1 1.5 2
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 03 5290
αJ 2000 = 14:03:22.27
δJ 2000 = 54:24:37.62
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
11

12. Star ID: 9490 03 6537
αJ 2000 = 14:03:23.44
δJ 2000 = 54:25:04.76
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 03 3806
αJ 2000 = 14:03:26.37
δJ 2000 = 54:24:11.63
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
12

13. Star ID: 9490 a1 416
αJ 2000 = 14:03:28.35
δJ 2000 = 54:17:07.58
+/- 5”
−2.5 −2 −1.5 −1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 a1 6401
αJ 2000 = 14:03:28.86
δJ 2000 = 54:21:28.94
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
13

14. Star ID: 9490 03 1487
αJ 2000 = 14:03:30.73
δJ 2000 = 54:23:35.66
+/- 5”
−0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 a1 7093
αJ 2000 = 14:03:32.78
δJ 2000 = 54:20:09.89
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
14

15. Star ID: V2
αJ 2000 = 14:03:32.88
δJ 2000 = 54:24:25.99
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
Star ID: 9490 b1 3762
αJ 2000 = 14:03:41.18
δJ 2000 = 54:19:05.30
+/- 5”
−1 −0.5 0 0.5 1 1.5 2 2.5
18
19
20
21
22
23
24
25
26
27
B−V [mag]
V[mag]
15