Prominence Studies.

Abstract

view Abstract Citations (11) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Prominence Studies. McMath, Robert R. ; Pettit, Edison Abstract Eruptive prominences.-Data for seven new eruptive prominences conftrm the laws of motion previously stated. The end velocity is now shown to revert occasionally to a whole multiple of the second preceding velocity, which explains some apparent excep- tions to the second law. One prominence reached the unparalleled height of 1,550,000 km and another the record velocity of 728 km/sec. The former was near the north pole of the sun. The dilemma of light-pressure-A calculation of the Milne effect shows that we can- not assume that light-pressure balances gravity at the sun's surface. Velocities of more than 100 km/sec are developed in a few minutes from an initial 10 km/sec velocity. Calcium tends to separate widely from hydrogen. Prominences of class 111.-The motions in the fountain-like loops of class IIIb prominences are down both branches from the ends of the bright tops of the arches. Practically all obey the first law, and about 20 per cent the second law of prominence motion; 7 cases show no change in velocity. Ejections-Small faint lumps of chromospheric matter are sometimes ejected from a spot area, often at considerable angles to the vertical. These ejections seem to move in nearly straight trajectories and do not return. Centers of attraction-Examination of the dissolution of an active prominence pro- jected on the disk shows that centers of attraction are not visible as surface markings. With one exception, prominence streamers have always been seen to enter centers of attraction from one side only. Fifty per cent of all the streamers from class I promi- nences measured followed both laws of prominence motion. Coronal prominences -When a center of attraction becomes very active, long stream- ers not connected with the active prominence enter the center of attraction from great heights. These seem to come from space in the middle or outer corona. They obey both laws of motion of eruptive prominences Publication: The Astrophysical Journal Pub Date: October 1938 DOI: 10.1086/143981 Bibcode: 1938ApJ....88..244M full text sources ADS |