Volume 437, Number 1, July I 2005
|Page(s)||297 - 302|
|Published online||10 June 2005|
Flares associated with abnormal rotation rates: Longitudinal minimum separation of leading and following sunspots
Indian Institute of Astrophysics, Bangalore-560034, India e-mail: firstname.lastname@example.org
2 Sree Krishna College, Guruvayur, Kerala-680102, India
Accepted: 1 February 2005
Using six years (1969-1974) of data of sunspot groups from the white light pictures of the Kodaikanal Observatory, we compute rotation rates of the leading and the following sunspots and the rate of change of longitudinal separation during their life times. We find that (i) the spots that are associated with abnormal rotation rates (i.e, rotation rates that are greater than 1σ from the mean rotation) and that approach at a separation rate of deg/day also experience minimum longitudinal separation (~) of their foot points during the course of their evolution; (ii) spots that have a minimum separation eventually trigger flares; and (iii) events with abnormal rotation rates and minimum approaching distances of the foot points occur on average during between of the life spans, indicating the annihilation of magnetic energy, probably below the surface. These results support the conventional physical scenario of magnetic reconnection that may be responsible for triggering flares.
Key words: sunspots / Sun: flares
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.