-- 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

Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg Brown_B-V_Diagram.jpg r1 manage 32.2 K 21 Feb 2019 - 13:58 AriannaSaba  
PNGpng Schermata_2019-02-21_alle_13.44.49.png r1 manage 71.2 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng Schermata_2019-02-21_alle_13.45.16.png r1 manage 71.4 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng Schermata_2019-02-21_alle_13.49.05.png r1 manage 81.8 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng Schermata_2019-02-21_alle_13.49.19.png r1 manage 80.5 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng m36_background_b.png r1 manage 38.8 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_background_g.png r1 manage 48.1 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_blue_stars_in_circle.png r1 manage 125.6 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_blue_stars_not_in_edges.png r1 manage 133.6 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_green_stars_in_circle.png r1 manage 124.6 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_green_stars_not_in_edges.png r1 manage 132.9 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_hr_diagram.png r1 manage 15.1 K 21 Feb 2019 - 13:51 AriannaSaba  
PNGpng m36_matched_stars.png r1 manage 27.1 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng m36_offset_stars.png r1 manage 26.4 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng m36_separation_histogram.png r1 manage 34.5 K 21 Feb 2019 - 13:52 AriannaSaba  
PNGpng m36_separation_histogram_bright_star.png r1 manage 31.1 K 21 Feb 2019 - 13:52 AriannaSaba  

Physics WebpagesRHUL WebpagesCampus Connect • Royal Holloway, University of London, Egham, Surrey TW20 0EX; Tel/Fax +44 (0)1784 434455/437520

Topic revision: r1 - 21 Feb 2019 - AriannaSaba

 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding RHUL Physics Department TWiki? Send feedback