A Caltech Library Service

Small Electron Events Observed by Parker Solar Probe/IS⊙IS during Encounter 2

Mitchell, J. G. and de Nolfo, G. A. and Hill, M. E. and Christian, E. R. and McComas, D. J. and Schwadron, N. A. and Wiedenbeck, M. E. and Bale, S. D. and Case, A. W. and Cohen, C. M. S. and Joyce, C. J. and Kasper, J. C. and Labrador, A. W. and Leske, R. A. and MacDowall, R. J. and Mewaldt, R. A. and Mitchell, D. G. and Pulupa, M. and Richardson, I. G. and Stevens, M. L. and Szalay, J. R. (2020) Small Electron Events Observed by Parker Solar Probe/IS⊙IS during Encounter 2. Astrophysical Journal, 902 (1). Art. No. 20. ISSN 1538-4357. doi:10.3847/1538-4357/abb2a4.

[img] PDF - Published Version
Creative Commons Attribution.


Use this Persistent URL to link to this item:


The current understanding of the characteristics of solar and inner heliospheric electron events is inferred almost entirely from observations made by spacecraft located at 1 astronomical unit (au). Previous observations within 1 au of the Sun, by the Helios spacecraft at ~0.3–1 au, indicate the presence of electron events that are not detected at 1 au or may have merged during transport from the Sun. Parker Solar Probe's close proximity to the Sun at perihelion provides an opportunity to make the closest measurements yet of energetic electron events. We present an overview of measurements of electrons with energies between ~17 keV and ~1 MeV made by the Parker Solar Probe Integrated Science Investigation of the Sun (IS⊙IS) instrument suite during Encounter 2 (2019 March 31–April 10 with perihelion of ~0.17 au), including several small electron events. We examine these events in the context of the electromagnetic and solar wind environment measured by the FIELDS and SWEAP instruments on Parker Solar Probe. We find most of these electron enhancements to be associated with type III radio emissions that reach the local plasma frequency and one enhancement that appears to be primarily associated with abrupt changes in the local magnetic field. Together, these associations suggest that these are indeed the first measurements of energetic electron events within 0.2 au.

Item Type:Article
Related URLs:
URLURL TypeDescription ItemIS⊙IS data and visualization tools ItemNASA Space Physics Data Facility
Mitchell, J. G.0000-0003-4501-5452
de Nolfo, G. A.0000-0002-3677-074X
Hill, M. E.0000-0002-5674-4936
Christian, E. R.0000-0003-2134-3937
McComas, D. J.0000-0001-6160-1158
Schwadron, N. A.0000-0002-3737-9283
Wiedenbeck, M. E.0000-0002-2825-3128
Bale, S. D.0000-0002-1989-3596
Case, A. W.0000-0002-3520-4041
Cohen, C. M. S.0000-0002-0978-8127
Joyce, C. J.0000-0002-3841-5020
Kasper, J. C.0000-0002-7077-930X
Labrador, A. W.0000-0001-9178-5349
Leske, R. A.0000-0002-0156-2414
MacDowall, R. J.0000-0003-3112-4201
Mewaldt, R. A.0000-0003-2178-9111
Mitchell, D. G.0000-0003-1960-2119
Pulupa, M.0000-0002-1573-7457
Richardson, I. G.0000-0002-3855-3634
Stevens, M. L.0000-0002-7728-0085
Szalay, J. R.0000-0003-2685-9801
Additional Information:© 2020. The Author(s). Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2020 May 20; revised 2020 July 24; accepted 2020 August 24; published 2020 October 8. We wish to acknowledge the support of NASA's Parker Solar Probe grant NNN06AA01C. We thank the Parker Solar Probe IS⊙IS, FIELDS, and SWEAP teams, including the engineers, technicians, administrators, and scientists, who developed the instruments used in this study. The IS⊙IS data and visualization tools are available to the community at:; data are also available via the NASA Space Physics Data Facility (
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Subject Keywords:Solar flares ; Solar energetic particles ; Solar particle emission ; Radio bursts ; Solar physics
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Solar flares (1496); Solar energetic particles (1491); Solar particle emission (1517); Radio bursts (1339); Solar physics (1476)
Record Number:CaltechAUTHORS:20201008-083809185
Persistent URL:
Official Citation:J. G. Mitchell et al 2020 ApJ 902 20
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105914
Deposited By: George Porter
Deposited On:08 Oct 2020 17:00
Last Modified:16 Nov 2021 18:47

Repository Staff Only: item control page