Rotation rates of leader and follower sunspots
We have measured the rotation rates of leader and follower sunspots found on Mount Wilson white light plates, for the years 1917--1983. We find that at all latitudes, leader spots rotate faster than follower spots by approx.0/sup 0/.1 per day, or 14 m s/sup -1/. We also find that, when examined separately, leaders and followers show the same variations in rotation with cycle phase as do all spots taken together, as reported earlier in Gilman and Howard. Leaders and followers show similar variations in rotation rate even on an annual basis. Thus, while leaders and followers in each group diverge in longitude from each other at an average rate of approx.0/sup 0/.1 per day, each is separately speeding up or slowing down its rotation according to the phase in the cycle, and by a similar amount. Leaders and followers also give about the same covariance of longitude and latitude motions, indicating that whole sunspot groups participate in tracing the apparent angular momentum transport toward the equator, as previously reported for all spots in Gilman and Howard.
- Research Organization:
- High Altitude Observatory/National Center for Atmospheric Research
- OSTI ID:
- 5307991
- Journal Information:
- Astrophys. J.; (United States), Vol. 295:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
ACTIVE LONGITUDES REVEALED BY LARGE-SCALE AND LONG-LIVED CORONAL STREAMERS
Distribution of sunspot umbral areas - 1917-1982