Sunspot positions and sizes for 1825-1867 from the observations by Samuel Heinrich SchwabeArlt, R., Leussu, R., Giese, N., Mursula, K. & Usoskin, I. G., 21-Aug-2013, In : Monthly Notices of the Royal Astronomical Society. 433, 4, p. 3165-3172 8 p.
Research output: Contribution to journal › Article › Academic › peer-review
Samuel Heinrich Schwabe made 8486 drawings of the solar disc with sunspots in the period from 1825 November 5 to 1867 December 29. We have measured sunspot sizes and heliographic positions on digitized images of these drawings. A total of about 135 000 measurements of individual sunspots are available in a data base. Positions are accurate to about 5 per cent of the solar radius or to about 3 degrees in heliographic coordinates in the solar-disc centre. Sizes were given in 12 classes as estimated visually with circular cursor shapes on the screen. Most of the drawings show a coordinate grid aligned with the celestial coordinate system. A subset of 1168 drawings have no indication of their orientation. We have used a Bayesian estimator to infer the orientations of the drawings as well as the average heliographic spot positions from a chain of drawings of several days, using the rotation profile of the present Sun. The data base also includes all information available from Schwabe on spotless days.
|Number of pages||8|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Publication status||Published - 21-Aug-2013|
- Sun: activity, sunspots, DIFFERENTIAL ROTATION, RECONSTRUCTION