Difference: Meeting2102 ( vs. 1)

Revision 121 Feb 2019 - AriannaSaba

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META TOPICPARENT name="StewartBoogertPhotometry2018"
-- AriannaSaba - 21 Feb 2019

m36_background_b.png

m36_background_g.png

Initial number of stars found were 85 with the blue filter and 82 with the green filter.m36_blue_stars_in_circle.pngm36_blue_stars_not_in_edges.png

m36_green_stars_in_circle.png

m36_green_stars_not_in_edges.png

After deleting the stars that lied in the edges of the frame, B: 79 stars, V: 76 stars.

Plotted the stars in the blue and the green in the same plot to see their offset

m36_offset_stars.png

Then calculated the offset for the brightest star and defined the delta x and delta y. moved each star in the blue frame by that delta x and delta y.

However, the stars did not match, except for the brigthest one, because the baricenters in B and V are calculated depending on the pixel values of the star. This means that the same star taken with the B filter could be 'bigger' than in the V filter. This causes an offset in the barycenter calculation between the two filters.

m36_matched_stars.png

Separation histogram was made after the offset calculation for the brightest star and for a random one, identified in the plot above. (Ignore light blue cross.)

m36_separation_histogram.png

Schermata_2019-02-21_alle_13.45.16.png

m36_separation_histogram_bright_star.png

Schermata_2019-02-21_alle_13.44.49.png

After matching the stars barycenters, this were the results obtained.

Schermata_2019-02-21_alle_13.49.19.pngSchermata_2019-02-21_alle_13.49.05.png

First HR diagram, only 19 stars have been matched. Have to work further on the algorithm that matches stars.m36_hr_diagram.png

compare with diagram found online:

Brown_B-V_Diagram.jpg

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