Book chapters will be unavailable on Saturday 24th August between 8am-12pm BST. This is for essential maintenance which will provide improved performance going forwards. Please accept our apologies for any inconvenience caused.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Magnetic instability is a key consideration for filament eruptions and subsequent CMEs. In this contribution we are considering different magnetic conditions for active and non-active regions, such as coronal hole regions and quiet sun, and also active regions of a simple magnetic configuration. The aim is to assess magnetic instability through potential and non-potential field modelling and 3D evaluation of the magnetic decay index. Some eruptive examples from solar cycle 24 using HMI/SDO data are presented, complemented with observations of AIA/SDO.
Observed P-Cygni line profiles in the UV spectra of central stars of Planetary Nebulae (PNN) obtained with the IUE satellite has been fitted by theoretical profiles in order to determine mass loss rates.
Different ESO-telescopes with medium resolution spectrographs and CCD-detectors were used to look for emission from extended halos around Planetary Nebulae. In three out of four cases the search was successful. The ratio Rhalo/Rneb ranges from 2 to about 10. Assuming that the halos have been produced by the winds of the Red Giant progenitor stars, we determine Ṁ/VAGB of these progenitors, using the measured Hα- and Hβ-fluxes. These values scatter in a relatively narrow range around 2‥5 · 10−7 (M⊙/y)/(km/s). In some objects emission line fluxes were measured at two ore more radial distances and radial density profiles were derived from them. These are in good agreement with the expected n∼r−2 density law expected for a freely expanding wind.
Flux emergence phenomena are relevant at different temporal and spatial scales. We have studied a flux emergence region underneath a filament. This filament elevated itself smoothly, and the associated CME reached the Earth. In this study we investigate the size and the amount of flux in the emergence event. The flux emergence site appeared just beneath a filament. The emergence acquired a size of 24 Mm in half a day. The unsigned magnetic flux density from LOS-magnetograms was around 1 kG at its maximum. The transverse field as well as the filament eruption were also analysed.
Email your librarian or administrator to recommend adding this to your organisation's collection.