Astrophysics and Space Science

, Volume 323, Issue 2, pp 135–145

On properties of narrow CMEs observed with SOHO/LASCO

  • Nishant Mittal
  • Kumud Pandey
  • Udit Narain
  • S. S. Sharma
Original Article

DOI: 10.1007/s10509-009-0055-1

Cite this article as:
Mittal, N., Pandey, K., Narain, U. et al. Astrophys Space Sci (2009) 323: 135. doi:10.1007/s10509-009-0055-1

Abstract

We have investigated properties such as speed, angular width, location, acceleration and occurrence rate of narrow CMEs (defined as having angular width ≤20°) observed during 1996–2007 by SOHO/LASCO. The results obtained are compared with those of normal CMEs (angular width >20°) from the same time interval to find whether there are any real differences between the two populations. Our study of 3464 narrow CMEs from the online SOHO/LASCO, CME catalogue leads us to conclude that (1) the fraction of narrow CMEs during solar minimum is 38% and during solar maximum 19%, (2) during solar maximum narrow CMEs are generally faster than normal CMEs, (3) the maximum speed of narrow CMEs is much smaller than that of the normal CMEs, (4) during solar maximum narrow CMEs appear at all latitudes similar to normal CMEs, (5) narrow and normal CMEs have unequal deceleration and (6) the occurrence rate of narrow CMEs remain constant after 1998 until the beginning of 2006 while the normal CMEs occurrence rate seems to follow solar cycle variation until 2004. Thus narrow CMEs and normal CMEs have some differences, in disagreement with previous studies.

Keywords

Sun Coronal mass ejections Narrow CMEs Solar cycle 23 

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Nishant Mittal
    • 1
    • 2
  • Kumud Pandey
    • 1
  • Udit Narain
    • 1
    • 2
  • S. S. Sharma
    • 1
  1. 1.Astrophysics Research GroupMeerut CollegeMeerutIndia
  2. 2.IUCAAPuneIndia

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