The numbers of faculae at the poles of the Sun have been estimated from white-light images obtained at the Mount Wilson Observatory during 1985–2006 and combined with prior estimates extending back to 1906 when the observations began. The combined data show an 11-yr cyclic variation with faculae maxima occurring during sunspot minima in each of the past 10 sunspot cycles. Also, these numbers of...

Coronal mass ejections (CMEs) are huge expulsions of magnetized matter from the Sun and stars, traversing space with speeds millions kilometers per hour. Solar CMEs can cause severe weather disturbances consumer power outages on Earth, whereas stellar may even pose a hazard to habitability exoplanets. While ejected by our be directly imaged white-light coronagraphs, for stars this is not possib...

We study the relationship between magnetic reconnection and acceleration of filaments and coronal mass ejections (CMEs) in different magnetic configurations. They occur in either quiet-Sun or active regions of either bipolar or multipolar magnetic fields, and are either or not accompanied by filament eruptions. The preliminary results of the case studies confirm the temporal correlation and mag...

[1] The relationship between the magnetic field intensity and speed of solar wind events is examined using 3 years of data from the ACE spacecraft. No preselection of coronal mass ejections (CMEs) or magnetic clouds is carried out. The correlation between the field intensity and maximum speed is shown to increase significantly when |B| > 18 nT for 3 hours or more. Of the 24 events satisfying th...

Abstract Stealthy coronal mass ejections (CMEs), lacking low signatures, may result in significant geomagnetic storms. However, the mechanism of stealthy CMEs is still highly debated. In this work, we investigate whether there are differences between and standard terms their dynamic behaviors. Seven eight with speeds selected. We calculate two-dimensional speed distributions based on cross-corr...

To this day, the prediction of space weather effects near the Earth suffers from a fundamental problem: The radial propagation speed of “halo” CMEs (i.e. CMEs pointed along the Sun-Earth-line that are known to be the main drivers of space weather disturbances) towards the Earth cannot be measured directly because of the unfavorable geometry. From inspecting many limb CMEs observed by the LASCO ...

Coronal Mass Ejections (CMEs), as they can inject a large amounts of mass and magnetic flux into the interplanetary space, are primary source space weather phenomena on Earth. The present review first briefly introduces solar surface signatures origins CMEs then focuses attempts to understand kinematic evolution from Sun have been observed in corona white-light series missions over last five de...

The Ultraviolet Coronagraph Spectrometer (UVCS) observed Doppler shifted material of a partial Halo Coronal Mass Ejection (CME) on December 13 2001. The observed ratio of [O V]/O V] is a reliable density diagnostic important for assessing the state of the plasma. Earlier UVCS observations of CMEs found evidence that the ejected plasma is heated long after the eruption. We have investigated the ...

We present a statistical result on the properties of solar source regions that have produced 57 fastest front-side coronal mass ejections (CMEs) (speed ≥1500 km s) occurred from 1996 June to 2007 January. The properties of these fast-CME-producing regions, 35 in total, are compared with those of all 1143 active regions (ARs) in the period studied. An automated method, based on SOHO/MDI magnetic...

We present a theoretical magnetohydrodynamic (MHD) model describing the time-dependent expulsion of a three-dimensional coronal mass ejection (CME) out of the solar corona. The model relates the white-light appearance of the CME to its internal magnetic Ðeld, which takes the form of a closed bubble, Ðlled with a partly anchored, twisted magnetic Ñux rope, and embedded in an otherwise open backg...