A New Expansive Catalog of Irradiance Coronal Dimming
Abstract
When coronal mass ejections (CMEs) depart the corona, they leave behind a transient void. Such a region evacuated of plasma is known as coronal dimming and it contains information about the kinematics of the CME that produced it. The dimming can be so great that it reduces the overall energy output of the star in particular emission lines, i.e., dimming is observable in spectral irradiance. This should be generally true for magnetically active stars.We use the Solar Dynamics Observatory (SDO) EUV Variability Experiment (EVE) data to search for and parameterize dimming. We search these light curves for dimming around >8,500 ≥C1 solar flares. In prior work, we have found that it is important to remove the gradual flare phase from dimming light curves in order to obtain slopes and magnitudes that are consistent with what can be obtained by spatially isolating flaring loops in spectral image data. Applying that method, we come to a total of ~13 million light curves in which to search for dimming. We parameterize each light curve in terms of magnitude, slope, and duration. Again in prior work, we've found that irradiance dimming magnitude and slope are indicators of CME mass and speed, respectively. Here, we briefly describe the feature detection and characterization algorithms developed and applied to the irradiance light curves. Machine learning techniques have been used for some of the backend processing pipeline. We also present statistics on the catalog itself. All of the code is open source python available on GitHub (github.com/jmason86/James-s-EVE-Dimming-Index-JEDI). This method may be capable of not only detecting CMEs from other stars, but estimating their kinetic energy and frequency of occurrence; information needed for assessing exoplanet habitability.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23535906M