ESAC SOHO Science Archive Tutorial
ESAC SOHO Science Archive Tutorial ESAC SOHO Science Archive Tutorial
67. Now we are going to repeat the same steps for another sunspot, this time at ahigher latitude, and between the dates: 27/12/2009 06:24 and 02/01/201018:42.68. Firstly, we'll take a look at the sunspots by building another movie. In the mainmenu of the SOHO Science Archive, select Windows -> Time Animator.69. The Time Animator window now opens. In the Instrument/Filter box select MDIContinuum, change the Resolution to 1024 and change the Max Number of EvenlySpaced Images to 300:70. In the Date Range fields choose from 27/12/2009 to 02/01/2010.71. Click the 'Search' button72. Once the movie has been built click on the 'Play Movie'. Choose one of the sunspotsand then download the images by doing the following:73. Go back to the SOHO Science Archive window and select the Search tab.74. In the Main Query Panel open the Begin Date Range and select 27/12/2009 and inthe End Date Range select 03/01/2010. In the Instrument section, scroll down andchoose MDI.75. Then click the 'Query' button in the bottom right corner.76. We are going to download the first MDI Continuum image in the list and the lastMDI Continuum image taken on the 02/01/2010:77. On the left of each observation click on the magnifying glass icon (show observationdetails):78. Right click on each thumbnail image and send both of them to Aladin.79. In Aladin, change the display of each image by selecting the pixel icon:80. Click on the 'Reverse' button, towards the centre of the Pixel mapping window andchange the 'Color map' from 'gray' to 'BB'.19
81. Select from the main menu 'Image -> Symmetry' and click Top/Bottom once andRight/Left once. Your image of the sun should now be the same as in the SOHOScience Archive: To calculate the differential rotation, first determine the position ofthe sunspot for the first and last image of this particular series. Take a look at themovie you made with the SSA and make a note of where the same sunspot appearsin each image (see below, marked with red circles):82. Make a note of the x and y pixel coordinates for the centre of the sunspot in thefirst and last images:27/12/2009 06:24 Sunspot (x, y) =02/01/2010 18:42 Sunspot (x, y) =83. Again, find the centre coordinates for the Sun (in pixels) and the Radius of the Sun(in pixels) by clicking on the properties icon.84. A properties window now opens. Select the 'Get original header' button.85. Another window opens called FITS header. The value giving the x centre coordinatefor the Sun is called CENTER_X. The value for the Y centre coordinate is calledCENTER_Y and the value for the radius of the Sun is called R_SUN. All of thesevalues are given in pixels.86. Make a note of these and add them to the Sunspot values you found earlier:27/12/2009 06:24 Sunspot (x, y) =Centre (CENTER_X, CENTER_Y) =Radius (R_SUN) =02/01/2010 18:42 Sunspot (x, y) =Centre (CENTER_X, CENTER_Y) =Radius (R_SUN) =20
- Page 1 and 2: SCIENCE ARCHIVES AND VO TEAMESAC SO
- Page 3 and 4: Table of contents1 BACKGROUND .....
- Page 5 and 6: 1 BACKGROUND1.1 SUNSPOTS• Sunspot
- Page 7 and 8: the Sun, they’d be the same in th
- Page 9 and 10: 2 DETERMINING THE SOLAR DIFFERENTIA
- Page 11 and 12: 13. CALCULATING THE SOLAR DIFFERENT
- Page 13 and 14: 24. Click the 'OK' button and go ba
- Page 15 and 16: 41. The observation details for thi
- Page 17 and 18: saved in, these formats also contai
- Page 19: 62. Record your values with the oth
- Page 23 and 24: 94. RESULTS:2005 dataset: Period is
- Page 25 and 26: 2005/01/17 16:00Use the grids to es
- Page 27 and 28: 2010/01/02 18:42Then carry on follo
- Page 29 and 30: 3 TROUBLESHOOTING TIPSHere we list
67. Now we are going to repeat the same steps for another sunspot, this time at ahigher latitude, and between the dates: 27/12/2009 06:24 and 02/01/201018:42.68. Firstly, we'll take a look at the sunspots by building another movie. In the mainmenu of the <strong>SOHO</strong> <strong>Science</strong> <strong>Archive</strong>, select Windows -> Time Animator.69. The Time Animator window now opens. In the Instrument/Filter box select MDIContinuum, change the Resolution to 1024 and change the Max Number of EvenlySpaced Images to 300:70. In the Date Range fields choose from 27/12/2009 to 02/01/2010.71. Click the 'Search' button72. Once the movie has been built click on the 'Play Movie'. Choose one of the sunspotsand then download the images by doing the following:73. Go back to the <strong>SOHO</strong> <strong>Science</strong> <strong>Archive</strong> window and select the Search tab.74. In the Main Query Panel open the Begin Date Range and select 27/12/2009 and inthe End Date Range select 03/01/2010. In the Instrument section, scroll down andchoose MDI.75. Then click the 'Query' button in the bottom right corner.76. We are going to download the first MDI Continuum image in the list and the lastMDI Continuum image taken on the 02/01/2010:77. On the left of each observation click on the magnifying glass icon (show observationdetails):78. Right click on each thumbnail image and send both of them to Aladin.79. In Aladin, change the display of each image by selecting the pixel icon:80. Click on the 'Reverse' button, towards the centre of the Pixel mapping window andchange the 'Color map' from 'gray' to 'BB'.19
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