Is the Asymmetric Cone Model for Halo Coronal Mass Ejections Correct?

A set of 106 limb CMEs which are wide and could be possible halo events, when directed towards Earth, are used to check the accuracy of the asymmetric cone model. For this purpose characteristics of CMEs (widths and radial speeds) measured for the possible halo CMEs are compared with these obtained for halo CMEs using the asymmetric cone model (Michalek, Solar Phys. 237, 101, 2006). It was shown that the width and speed distributions for both datasets are very similar and with a probability of p>0.93 (using the Kolmogorov – Smirnov test) were drawn from the same distribution of events. We also determined the accurate relationship between radial (V _rad) and expansion (V _exp) speeds of halo CMEs. This relation for the halo CMEs is simply V _rad=V _exp and could be very useful for space weather application.     

Characteristics of DH type II bursts, CMEs and flares with respect to the acceleration of CMEs

A detailed investigation on DH-type-II radio bursts recorded in Deca-Hectometer (hereinafter DH-type-II) wavelength range and their associated CMEs observed during the year 1997–2008 is presented. The sample of 212 DH-type-II associated with CMEs are classified into three populations: (i) Group I (43 events): DH-type-II associated CMEs are accelerating in the LASCO field view (a>15 m s⁻²); (ii) Group II (99 events): approximately constant velocity CMEs (−15<a<15 m s⁻²) and (iii) Group III (70 events): represents decelerating CMEs (a<−15 m s⁻²). Our study consists of three steps: (i) statistical properties of DH-type-II bursts of Group I, II and III events; (ii) analysis of time lags between onsets of flares and CMEs associated with DH-type-II bursts and (iii) statistical properties of flares and CMEs of Group I, II and III events. We found statistically significant differences between the properties of DH-type-II bursts of Group I, II and III events. The significance (P _a ) is found using the one-way ANOVA-test to examine the differences between means of groups. For example, there is significant difference in the duration (P _a =5%), ending frequency (P _a =4%) and bandwidth (P _a =4%). The accelerating and decelerating CMEs have more kinetic energy than the constant speed CMEs. There is a significant difference between the nose height of CMEs at the end time of DH-type-IIs (P _a ≪1%). From the time delay analysis, we found: (i) there is no significant difference in the delay (flare start—DH-type-II start and flare peak—DH-type-II start); (ii) small differences in the time delay between the CME onset and DH-type-II start, delay between the flare start and CME onset times. However, there are high significant differences in: flare duration (P _a =1%), flare rise time (P _a =0.5%), flare decay time (P _a =5%) and CMEs speed (P _a ≪1%) of Group I, II and III events. The general LASCO CMEs have lower width and speeds when compared to the DH CMEs. It seems there is a strong relation between the kinetic energy of CMEs and DH-type-II properties.     

Radial Evolution of Well-Observed Slow CMEs in the Distance Range 2 – 30 <Emphasis Type="Italic">R</Emphasis><Subscript>⊙</Subscript>

We performed a detailed analysis of 27 slow coronal mass ejections (CMEs) whose heights were measured in at least 30 coronagraphic images and were characterized by a high quality index (≥4). Our primary aim was to study the radial evolution of these CMEs and their properties in the range 2 – 30 solar radii. The instantaneous speeds of CMEs were calculated by using successive height – time data pairs. The obtained speed – distance profiles [v(R)] are fitted by a power law v = a(R−b) ^c . The power-law indices are found to be in the ranges a=30 – 386, b=1.95 – 3.92, and c=0.03 – 0.79. The power-law exponent c is found to be larger for slower and narrower CMEs. With the exception of two events that had approximately constant velocity, all events were accelerating. The majority of accelerating events shows a v(R) profile very similar to the solar-wind profile deduced by Sheeley et al. (Astrophys. J. 484, 472, 1997). This indicates that the dynamics of most slow CMEs are dominated by the solar wind drag.     

Characteristics of CMEs associated with solar flares and DH type II radio bursts based on source position

We studied the characteristics of Coronal Mass Ejections (CMEs) associated with solar flares and Deca-Hectometric (DH) type II radio bursts, based on source position during 23rd solar cycle (1997–2007). We classified these CME events into three groups using solar flare locations as, (i) disk events (0–30^∘); (ii) intermediate events (31–60^∘) and (iii) limb events (61–90^∘). Main results from this studies are, (i) the number of CMEs associated with solar flares and DH-type IIs decreases as the source position approaches from disk to limb, (ii) most of the DH CMEs are halo (72%) in disk events and the number of occurrence of halo CMEs decreases from disk to limb, (iii) the average width and speed of limb events (164^∘ and 1447 km s⁻¹) are higher than those of disk events (134^∘ and 1035 km s⁻¹) and intermediate events (146^∘ and 1170 km s⁻¹) and (iv) the average accelerations for disk, intermediate and limb events are −8.2 m s⁻², −10.3 m s⁻² and −4.5 m s⁻² respectively. These analysis of CMEs properties show more dependency on longitude and it gives strong evidence for projection effect.     

Average Thickness of Magnetosheath Upstream of Magnetic Clouds at 1 AU versus Solar Longitude of Source

Starting with a large number (N=100) of Wind magnetic clouds (MCs) and applying necessary restrictions, we find a proper set of N=29 to investigate the average ecliptic plane projection of the upstream magnetosheath thickness as a function of the longitude of the solar source of the MCs, for those cases of MCs having upstream shock waves. A few of the obvious restrictions on the full set of MCs are the need for there to exist a driven upstream shock wave, knowledge of the MC’s solar source, and restriction to only MCs of low axial latitudes. The analysis required splitting this set into two subsets according to average magnetosheath speed: slow/average (300 – 500 km s⁻¹) and fast (500 – 1100 km s⁻¹) speeds. Only the fast set gives plausible results, where the estimated magnetosheath thickness (ΔS) goes from 0.042 to 0.079 AU (at 1 AU) over the longitude sector of 0° (adjusted source-center longitude of the average magnetic cloud) to 40° off center (East or West), based on N=11 appropriate cases. These estimates are well determined with a sigma (σ) for the fit of 0.0055 AU, where σ is effectively the same as (chi-squared) for the appropriate quadratic fit. The associated linear correlation coefficient for ΔS versus |Longitude| was very good (c.c.=0.93) for the fast range, and ΔS at 60° longitude is extrapolated to be 2.7 times the value at 0°. For the slower speeds we obtain the surprising result that ΔS is typically more-or-less constant at 0.040±0.013 AU at all longitudes, indicating that the MC as a driver, when moving close to the normal solar wind speed, has little influence on magnetosheath thickness. In some cases, the correct choice between two candidate solar-source longitudes for a fast MC might be made by noting the value of the observed ΔS just upstream of the MC. Also, we point out that, for the 29 events, the average sheath speed was well correlated with the quantity ΔV[=(〈V _MC〉−〈V _UPSTREAM〉)], and also with both 〈V _MC〉 and 〈V _MC,T〉, where 〈V _MC〉 is the first one-hour average of the MC speed, 〈V _MC,T〉 is the average MC speed across the full MC, and 〈V _UPSTREAM〉 is a five-hour average of the solar wind speed just upstream of the shock.     

Scalar field as dark energy accelerating expansion of the Universe

The features of a homogeneous scalar field ϕ with classical Lagrangian L = ϕ_;i ϕ^;i /2 − V(ϕ) and tachyon field Lagrangian L = −V(ϕ)√1 − ϕ_;i ϕ^;i causing the observable accelerated expansion of the Universe are analyzed. The models with constant equation-of-state parameter w _de = p _de/ρ_de < −1/3 are studied. For both cases the fields ϕ(a) and potentials V(a) are reconstructed for the parameters of cosmological model of the Universe derived from the observations. The effect of rolling down of the potential V(ϕ) to minimum is shown. Published in Ukrainian in Kinematika i Fizika Nebesnykh Tel, 2008, Vol. 24, No. 5, pp. 345–359. The article was translated by the authors.     

An Analytical Model to Predict the Arrival Time of Interplanetary CMEs

Referring to the aerodynamic drag force, we present an analytical model to predict the arrival time of coronal mass ejections (CMEs). All related calculations are based on the expression for the deceleration of fast CMEs in the interplanetary medium (ICMEs), [(v)\dot]=-\frac115 700(v-V_SW)²\dot{v}=-\frac{1}{15\,700}(v-V_{\mathrm{SW}})^{2} , where V _SW is the solar wind speed. The results can reproduce well the observations of three typical parameters: the initial speed of the CME, the speed of the ICME at 1 AU and the transit time. Our simple model reveals that the drag acceleration should be really the essential feature of the interplanetary motion of CMEs, as suggested by Vršnak and Gopalswamy (J. Geophys. Res. 107, 1019, 2002).     

Evolution of Coronal Mass Ejections in the Inner Heliosphere: A Study Using White-Light and Scintillation Images

Knowledge of the radial evolution of the coronal mass ejection (CME) is important for the understanding of its arrival at the near-Earth space and of its interaction with the disturbed/ambient solar wind in the course of its travel to 1 AU and further. In this paper, the radial evolution of 30 large CMEs (angular width > 150^∘, i.e., halo and partial halo CMEs) has been investigated between the Sun and the Earth using (i) the white-light images of the near-Sun region from the Large Angle Spectroscopic Coronagraph (LASCO) onboard SOHO mission and (ii) the interplanetary scintillation (IPS) images of the inner heliosphere obtained from the Ooty Radio Telescope (ORT). In the LASCO field of view at heliocentric distances R≤30 solar radii (R_⊙), these CMEs cover an order of magnitude range of initial speeds, V_CME≈260–2600 km s⁻¹. Following results have been obtained from the speed evolution of these CMEs in the Sun–Earth distance range: (1) the speed profile of the CME shows dependence on its initial speed; (2) the propagation of the CME goes through continuous changes, which depend on the interaction of the CME with the surrounding solar wind encountered on the way; (3) the radial-speed profiles obtained by combining the LASCO and IPS images yield the factual view of the propagation of CMEs in the inner heliosphere and transit times and speeds at 1 AU computed from these profiles are in good agreement with the actual measurements; (4) the mean travel time curve for different initial speeds and the shape of the radial-speed profiles suggest that up to a distance of ∼80 R_⊙, the internal energy of the CME (or the expansion of the CME) dominates and however, at larger distances, the CME's interaction with the solar wind controls the propagation; (5) most of the CMEs tend to attain the speed of the ambient flow at 1 AU or further out of the Earth's orbit. The results of this study are useful to quantify the drag force imposed on a CME by the interaction with the ambient solar wind and it is essential in modeling the CME propagation. This study also has a great importance in understanding the prediction of CME-associated space weather at the near-Earth environment.     

Distinctions between the characteristics of before and after DH CMEs associated flares

A detailed analysis of characteristics of coronal mass ejections and flares associated with deca-hectometer wavelength type-II radio bursts (DH-CMEs and DH-flares) observed in the period 1997–2008 is presented. A sample of 62 limb events is divided into two populations known as after-flare CMEs (AF-CMEs) and before-flare CMEs (BF-CMEs) based on the relative timing of the flare and CME onsets. On average, AF-CMEs (1589 km s⁻¹) have more speed than the BF-CMEs (1226 km s⁻¹) and the difference between mean values are highly significant (P∼2%). The average CME nose height at the time of type-II start is at larger distance for AF-CMEs than the BF-CMEs (4.89 and 3.84 R _o, respectively). We found a good anti-correlation for accelerating (R _a=−0.89) and decelerating (R _d=−0.78) AF-CMEs. In the case of decelerating BF-CMEs, the correlation seems to be similar to that for decelerating AF-CMEs (R _d=−0.83). The number of decelerating AF-CMEs is 51% only; where as, the number of decelerating BF-CMEs is 83%. The flares associated with BF-CMEs have shorter rise and decay times than flares related to AF-CMEs. We found statistically significant differences between the two sets of associated DH-type-II bursts characteristics: starting frequency (P∼4%), drift rate (P∼1%), and ending frequency (P∼6%). The delay time analysis of DH-type-II start and flare onset times shows that the time lags are longer in AF-CME events than in BF-CME events (P≪1%). From the above results, the AF-CMEs which are associated with DH-type-II bursts are found to be more energetic, associated with long duration flares and DH-type-IIs of lower ending frequencies.     

A massive, dusty toroid with large grains in the pre-planetary nebula IRAS22036+5306

Using the Submillimeter Array (SMA), we have obtained high angular-resolution (∼1″) interferometric maps of the submillimeter (0.88 mm) continuum and CO J=3–2 line from IRAS 22036+5306 (I 22036), a bipolar pre-planetary nebula (PPN) with knotty jets discovered in our HST SNAPshot survey of young PPNe. In addition, we have obtained supporting lower-resolution (∼10″) 2.6 mm continuum and CO, ¹³CO J=1–0 observations with the Owens Valley Radio Observatory (OVRO) interferometer. We find an unresolved source of submillimeter (and millimeter-wave) continuum emission in I 22036, implying a very substantial mass (0.02–0.04M _⊙) of large (i.e., radius ≳1 mm), cold (≲50 K) dust grains associated with I 22036’s toroidal waist. The CO J=3–2 observations show the presence of a very fast (∼220 km s⁻¹), highly collimated, massive (0.03M _⊙) bipolar outflow with a very large scalar momentum (about 10³⁹ g cm s⁻¹), and the characteristic spatio-kinematic structure of bow-shocks at the tips of this outflow. The fast outflow in I 22036, as in most PPNe, cannot be driven by radiation pressure. The large mass of the torus suggests that it has most likely resulted from common-envelope evolution in a binary, however it remains to be seen whether or not the time-scales required for the growth of grains to millimeter sizes in the torus are commensurate with such a formation scenario. The presence of the torus should facilitate the formation of the accretion disk needed to launch the jet. We also find that the ¹³C/¹²C ratio in I 22036 is very high (0.16), close to the maximum value achieved in equilibrium CNO-nucleosynthesis (0.33). The combination of the high circumstellar mass (i.e., in the torus and an extended dust shell inferred from ISO far-infrared spectra) and the high ¹³C/¹²C ratio in I 22036 provides strong support for this object having evolved from a massive (≳4M _⊙) progenitor in which hot-bottom-burning has occurred.     

Helical Eruptive Prominence Associated with a Pair of Overlapping CMEs on 21 April 2001

The eruption of limb prominence on 21 April 2001 associated with two coronal mass ejections (CMEs) is investigated. Hα images reveal two large-scale eruptions (a prominence body and a southern foot-point arch), both showing helical internal structure. These two eruptions are found to be spatially and temporally associated with the corresponding CMEs. The kinematics and the study of geometrical parameters of the prominence show that the eruption was quite impulsive (with peak acceleration ≈470 m s⁻²) and has taken place for relatively low pitch angle of helical threads, not exceeding tan θ≈1.2. The stability criteria of the prominence are revisited in the light of the model of Vršnak (1990, Solar Phys. 129, 295) and the analysis shows that the eruption violates the instability criteria of that model. Finally, the energy stored in the prominence circuit and the energies (kinetic, potential, and magnetic) of the associated CMEs are estimated and it is found that there was enough energy stored in the prominence to drive the two CMEs. S.S. Ali is on leave from Aligarh Muslim University, Aligarh, 202 002, India.     

Dynamic and Thermal Disappearance of Prominences and Their Geoeffectiveness

This paper is a qualitative study of 42 events of solar filament/prominence sudden disappearances (“disparitions brusques”; henceforth DBs) around two solar minima, 1985 – 1986 and 1994. The studied events were classified as 17 thermal and 25 dynamic disappearances. Associated events, i.e. coronal mass ejections (CMEs), type II bursts, evolution of nearby coronal holes, as well as solar wind speed, and geomagnetic disturbances are discussed. We have found that about 50% of the thermal DBs with adjacent (within 15° from the DB) coronal holes were associated with CMEs within a selected time window. All the studied thermal disappearances with adjacent coronal holes or accompanied by dynamic disappearances were associated with weak and medium geomagnetic storms. Also, nearly 64% of dynamic DBs were associated with CMEs. Ten (40%) dynamic disappearances were associated with intense geomagnetic storms, even when no CMEs was reported, six (24%) dynamic disappearances corresponded to extreme storms, and five (20%) corresponded to medium geomagnetic storms. The extreme geomagnetic storms appeared to be related to combined events, involving dynamic disappearances with adjacent coronal holes or including thermal disappearances. Furthermore, the geomagnetic activity (Dst index) increased if the source was close to the central meridian (±30°). The highest interplanetary magnetic field (B), longest duration, lowest southward direction B _z component, and lowest Dst were highly correlated for all studied events. The Sun – Earth transit time computed from the starting time of the sudden disappearance and the time its effect was measured at Earth was about 4.3 days and was mainly well correlated with the solar wind speed measured in situ (daily value).     

Streamer Belt and Chains as the Main Sources of Quasi-Stationary Slow Solar Wind

Synoptic maps of white-light coronal brightness from SOHO/LASCO C2 and distributions of solar wind velocity obtained from interplanetary scintillation are studied. Regions with velocity V≈300 – 450 km s⁻¹ and increased density N>10 cm⁻³, typical of the “slow” solar wind originating from the belt and chains of streamers, are shown to exist at Earth’s orbit, between the fast solar wind flows (with a maximum velocity V _max≈450 – 800 km s⁻¹). The belt and chains of streamers are the main sources of the “slow” solar wind. As the sources of “slow” solar wind, the contribution from the chains of streamers may be comparable to that from the streamer belt.     

The total photospheric motion field

Brief consideration is given to the conception of the total photospheric motion field. A synthesis of the most thorough investigations is made and the radial (V ^rad) and tangential (V ^tg) components of the velocity amplitude of the total photospheric motion field are deduced. At depth logτ₅ = ?3.0 V ^rad and V ^tg have average values of 1.2 and 1.7 km s^?1 respectively. They increase smoothly with depth and reach their maximum values of V ^rad=3.0, V ^tg=3.4 km s^?1 at depths logτ₅= ?0.2 and logτ₅ = +0.4 respectively. In the deep photospheric layers both components seem to decrease with depth.     

Relative Kinematics of the Leading Edge and the Prominence in Coronal Mass Ejections

We present a statistical analysis of the relationship between the kinematics of the leading edge and the eruptive prominence in coronal mass ejections (CMEs). We study the acceleration phase of 18 CMEs in which kinematics was measured from the pre-eruption stage up to the post-acceleration phase. In all CMEs, the three part structure (the leading edge, the cavity, and the prominence) was clearly recognizable from early stages of the eruption. The data show a distinct correlation between the duration of the leading edge (LE) acceleration and eruptive prominence (EP) acceleration. In the majority of events (78%) the acceleration phase onset of the LE is very closely synchronized (within ± 20 min) with the acceleration of EP. However, in two events the LE acceleration started significantly earlier than the EP acceleration (> 50 min), and in two events the EP acceleration started earlier than the LE acceleration (> 40 min). The average peak acceleration of LEs (281 m s⁻²) is about two times larger than the average peak acceleration of EPs (136 m s⁻²). For the first time, our results quantitatively demonstrate the level of synchronization of the acceleration phase of LE and EP in a rather large sample of events, i.e., we quantify how often the eruption develops in a “self-similar” manner.     

Gnevyshev Peaks and Gaps for Coronal Mass Ejections of Different Widths Originating in Different Solar Position Angles

The sunspot number series at the peak of sunspot activity often has two or three peaks (Gnevyshev peaks; Gnevyshev, Solar Phys. 1, 107, 1967; Solar Phys. 51, 175, 1977). The sunspot group number (SGN) data were examined for 1997 – 2003 (part of cycle 23) and compared with data for coronal mass ejection (CME) events. It was noticed that they exhibited mostly two Gnevyshev peaks in each of the four latitude belts 0° – 10°, 10° – 20°, 20 ° – 30°, and > 30°, in both N (northern) and S (southern) solar hemispheres. The SGN were confined to within latitudes ± 50° around the Equator, mostly around ± 35°, and seemed to occur later in lower latitudes, indicating possible latitudinal migration as in the Maunder butterfly diagrams. In CMEs, less energetic CMEs (of widths < 71°) showed prominent Gnevyshev peaks during sunspot maximum years in almost all latitude belts, including near the poles. The CME activity lasted longer than the SGN activity. However, the CME peaks did not match the SGN peaks and were almost simultaneous at different latitudes, indicating no latitudinal migration. In energetic CMEs including halo CMEs, the Gnevyshev peaks were obscure and ill-defined. The solar polar magnetic fields show polarity reversal during sunspot maximum years, first at the North Pole and, a few months later, at the South Pole. However, the CME peaks and gaps did not match with the magnetic field reversal times, preceding them by several months, rendering any cause – effect relationship doubtful.     

A Study of Surges: II. On the Relationship between Chromospheric Surges and Coronal Mass Ejections

Liu et al. (Astrophys. J. 628, 1056, 2005a) described one surge – coronal mass ejection (CME) event showing a close relationship between solar chromospheric surge ejection and CME that had not been noted before. In this work, large Hα surges (>72 Mm, or 100 arcsec) are studied. Eight of these were associated with CMEs. According to their distinct morphological features, Hα surges can be classified into three types: jetlike, diffuse, and closed loop. It was found that all of the jetlike surges were associated with jetlike CMEs (with angular widths ≤30 degrees); the diffuse surges were all associated with wide-angle CMEs (e.g., halo); the closed-loop surges were not associated with CMEs. The exclusive relation between Hα surges and CMEs indicates difference in magnetic field configurations. The jetlike surges and related narrow CMEs propagate along coronal fields that are originally open. The unusual transverse mass motions in the diffuse surges are suggested to be due to magnetic reconnections in the corona that produce wide-angle CMEs. For the closed-loop surges, their paths are just outlining stable closed loops close to the solar surface. Thus no CMEs are associated with them.     

PLATO: PLAnetary Transits and Oscillations of stars

The PLAnetary Transits and Oscillations of stars Mission (PLATO), presented to ESA in the framework of its “Cosmic Vision” programme, will detect and characterize exoplanets by means of their transit signature in front of a very large sample of bright stars, and measure the seismic oscillations of the parent stars orbited by these planets in order to understand the properties of the exoplanetary systems. PLATO is the next-generation planet finder, building on the accomplishments of CoRoT and Kepler: i) it will observe significantly more stars, ii) its targets will be 2 to 3 magnitudes brighter (hence the precision of the measurements will be correspondingly greater as will be those of post-detection investigations, e.g. spectroscopy, asteroseismology, and eventually imaging), iii) it will be capable of observing significantly smaller exoplanets. The space-based observations will be complemented by ground- and space-based follow-up observations. These goals will be achieved by a long-term (4 years), high-precision, high-time-resolution, high-duty-cycle monitoring in visible photometry of a sample of more than 100,000 relatively bright (m _V  ≤ 12) stars and another 400,000 down to m _V  = 14. Two different mission concepts are proposed for PLATO: i) a “staring” concept with 100 small, very wide-field telescopes, assembled on a single platform and all looking at the same 26° diameter field, and ii) a “spinning” concept with three moderate-size telescopes covering more than 1400 degree². See for The PLATO Consortium.     

Discovery of a Giant Radio Halo in a Massive Merging Cluster at z?=?0.443

We have discovered a giant radio halo in the massive merging cluster MACSJ0417.5-1154. This cluster, at a redshift of 0.443, is one of the most X-ray luminous galaxy cluster in the MAssive Cluster Survey (MACS) with an X-ray luminosity in the 0.1–2.4 keV band of 2.9×10⁴⁵ erg s^− 1. Recent observations from GMRT at 230 and 610 MHz have revealed a radio halo of ∼ 1.2 × 0.3 Mpc² in extent. This halo is elongated along the North-West, similar to the morphology of the X-ray emission from Chandra. The 1400 MHz radio luminosity (L _r) of the halo is ∼2 × 10²⁵ W Hz^− 1, in good agreement with the value expected from the L _x − L _r correlation for cluster halos.     

Correlation Analyses Between the Characteristic Times of Gradual Solar Energetic Particle Events and the Properties of Associated Coronal Mass Ejections

It is generally believed that gradual solar energetic particles (SEPs) are accelerated by shocks associated with coronal mass ejections (CMEs). Using an ice-cream cone model, the radial speed and angular width of 95 CMEs associated with SEP events during 1998 – 2002 are calculated from SOHO/LASCO observations. Then, we investigate the relationships between the kinematic properties of these CMEs and the characteristic times of the intensity-time profile of their accompanied SEP events observed at 1 AU. These characteristic times of SEP are i) the onset time from the accompanying CME eruption at the Sun to the SEP arrival at 1 AU, ii) the rise time from the SEP onset to the time when the SEP intensity is one-half of peak intensity, and iii) the duration over which the SEP intensity is within a factor of two of the peak intensity. It is found that the onset time has neither significant correlation with the radial speed nor with the angular width of the accompanying CME. For events that are poorly connected to the Earth, the SEP rise time and duration have no significant correlation with the radial speed and angular width of the associated CMEs. However, for events that are magnetically well connected to the Earth, the SEP rise time and duration have significantly positive correlations with the radial speed and angular width of the associated CMEs. This indicates that a CME event with wider angular width and higher speed may more easily drive a strong and wide shock near to the Earth-connected interplanetary magnetic field lines, may trap and accelerate particles for a longer time, and may lead to longer rise time and duration of the ensuing SEP event.