Acceleration of Coronal Mass Ejection Plasma in the Low Corona as Measured by the Citizen CATE Experiment

Matthew Penn ,Lavor R Jenkins,Bruce Alder,Thomas G Garrison ,Dylan Boggs,Ashley Staab,Logan Neuroth,Jacob Watson ,Dimitri Klebe ,Mark Redecker,Julian Web ,Robert Mcgowen,Daniel M Smith ,Debbie Penn,Joseph A Shaw ,Geri Hall-Conley,Kate Allen-Penn,Kerry Glenn,Kateri Cardenas,Donald K Walter ,Thomas Ballew,Jack Jensen,Marley Carey,Kristen L Stives ,Mark Bremer,Rachel Manspeaker,Margaret Cortez,Thomas Vanderhorst,Cole Bramhall,Spencer L Buckner ,Denese Lighthill,Martin Hiner,Zach Stockbridge,A J Allen ,Bob Anderson,Chris Mandrell,D J Matthews ,Makai Jensen,S Oughton C W Smith ,Madison Kroeger,Madison Mas,Karan Davis,Stephen R Mcneil ,Mary-Beth Ledford,J Payne ,Austen Kenney,Alyssa Levsky,Kolby Pisciotti,Daniel Zavala,Kaleb Kautzsch,Zachery Brasier,Trevor Schmale,Michael Pierce,Amy Riddle,Kallen Smith,Russell V Lucas ,Burton Briggs ,Sanjay Gosain,Damani Proctor,Amy R Winebarger ,Maria Baker,Rein Lann,Taylor Shivelbine,Duane Gregg,J R L Anderson ,S Brittain ,Liam Brook,Kiley Brown,David Dembinski ,Capp Yess,James H Stith ,Bentley Bee,Honor Hare,P R Blanco ,Myles Mckay,Alex Falatoun,Austin Ryan ,Andreea Boeck,David Higgins,Bart Tolbert,Arnie Cerny,Corey Pantuso,Michael Rodgers ,Brain Baker,Serena Hill Laroche,Eleanor Doucette,Gage Brandon,Stephen P Gulley ,Michael Freed ,Richard Gelderman,Ella Erickson,Elliott Iwen,Andrei Ursache,Beth Short,Billyjoe Menard,Anne L Simacek ,Richard L Kautz ,Maryanne Angliongto,Zachary Whipps,Richard Mcfate,Katsina Cardenas,Sam Streeter,Ethan Caudill,Kameron Brough,Kellyn Chandler,Michaela Springer,C F Claver ,Lucy Kegley,Steven Somes,Donavan Smith,Julie Vanvoorhis,Charlie Wessinger,Jane Earp,Robert Baer ,Russ Longhurst,Vanshita Gosain ,Michele Wistisen,Jordan Duncan,A Roberts ,Wayne Boeck ,Mark Steward ,Stanley Jensen ,Declan Jensen,J Kamenetzky ,Tiffany Rivera ,Sam Fincher,Jenna Claver ,Valerie Granger,Wilson Harris,Tessa Hoffman,Alexander Beltzer-Sweeney,Howard Harper,D Elmore ,Mary Kidd ,Doug Scribner,Drew Hathaway,Patricia Thompson ,Sean Baldridge,Yolanta G Simacek,Gerald Matzek,Gabriel Wierzorec,Sean Patrick ,Eric Weitzel Team ,G Gisler ,Jessica H Lewis ,Chris Midden,Jennifer Hammock,R Wright ,Jalynne Brough,Savannah Shoffner,Jerry Zissett,I Birriel ,Michael Meo,Claire A Hart ,Zack Nelson,Emilie Mcclellan,Danielle Hoops,Bryan Scherrer,Connor Worthen,Jeannine Schilling,Jeffrey Dimatties,Nathan Pindell,Alexus Cochran,Sepehr Ardebilianfard,Ned P Smith ,J Byrnes ,Thomas A Schad ,James R Foster ,David Garrison ,Harrison Leiendecker,Theresa Bautz,Corina Ursache ,Mason Perrone,Dylan Garrison,Richard Lighthill,Maya Rogers,Rob Sobnosky,Dawson Poste,Christian Nations,Shae Aagard,Bruno Acevedo,Chris Bremer,Dawn Cynamon,Isabel Crooker,David J Anderson ,Erin L Thompson ,Lynn M Powers ,Jennifer Wellman,Peter V Nguyen ,Ben Fagan,Allyn Smith ,Charles Cynamon ,Brian Jackson ,Tyler V Howard ,Caleb Russell,Ione Chandler,Jeremy M Weremeichik ,Monty Laycox,Reba Doucette,Lydia Hinkle,Jared Hettick,Katie Barngrover,Jeffrey Johnson ,D W Gerdes ,Pat Boyce,Fred Isberner ,Mason Moore,Scott Dixon ,Z Watson ,Samantha Hasler,Joe Meyer,Wesley Sandidge,Michelle Deady,Dinuka Gallaba ,Dylan Sandbak,Janet Jorgensen,Elijah Pelofske,Ethan Orr,A K Speck ,Nolan Sump,Lynne M.a Dorsey ,Ryan H Claver,Logan Jensen,Ruchi Gosain,Daniel Stelly,Jonathan Mangin,Charles Kennedy,Grady Boyce,Jay Kerr,Kyle Scholtens,Bruce W Callen ,Alexandria Temple,Mohammad Ahmadbasir,Isaac Mangin,Harrison Roberts,Jasmyn Taylor,Kyle Dawson ,Katherine G Weber ,N R Sheeley ,E Rivera ,Mariana Lazarova ,Mine Anderson,Brynn Brettell,Jordan Bavlnka,Ryan M Maderak ,Mike Conley,D T Young ,Shaedyn Miller,Jean A Dupree,S Joseph Wright ,Jack S Benner ,Caitlin Lynch,Ben Farid Røjgaard Nielsen ,Joe Earp,P A Yanamandra-Fisher ,Jagert Ernzen,Ryan Alder ,D Slimmer ,Peggy Hill ,Jennifer Birriel ,Adrianna Mitchell,Bryan Costanza,Llanee Gibson,Jim Dickens ,Samuel Cynamon,Ben Trumpenski,Mark P Roy ,Lindsay Adams,Kelly D Quinn-Hughes ,Michael Laroche,G W Ojakangas ,Sarah Kovac,Tim Nelson,Thomas K Simacek,Morgyn Church,Bob Blair,Orion Bellorado,Irene Pease,Andi York,Michael J Foster ,M Mcclellan ,Prescott Moore,Jack Erickson,Doug Justice,Gabrielle W Roberts,William L Garrison ,Elena Ursache

doi:10.1088/1538-3873/ab558c

Abstract

The citizen Continental-America Telescopic Eclipse (CATE) Experiment was a new type of citizen science experiment designed to capture a time sequence of white-light coronal observations during totality from 17:16 to 18:48 UT on 2017 August 21. Using identical instruments the CATE group imaged the inner corona from 1 to 2.1 RSun with 1.″43 pixels at a cadence of 2.1 s. A slow coronal mass ejection (CME) started on the SW limb of the Sun before the total eclipse began. An analysis of CATE data from 17:22 to 17:39 UT maps the spatial distribution of coronal flow velocities from about 1.2 to 2.1 RSun, and shows the CME material accelerates from about 0 to 200 km s−1 across this part of the corona. This CME is observed by LASCO C2 at 3.1–13 RSun with a constant speed of 254 km s−1. The CATE and LASCO observations are not fit by either constant acceleration nor spatially uniform velocity change, and so the CME acceleration mechanism must produce variable acceleration in this region of the corona.

Highlights

The inner corona is notoriously difficult to study, but it is the region where coronal mass ejections (CMEs) are accelerated
The data set collected by the Citizen Continental-America Telescopic Eclipse (CATE) Experiment from the 2017 total solar eclipse is unique
The white light images show coronal material escaping from the Sun during the late phase of a slow CME event which occurred before the eclipse; previous studies report the acceleration of fast CME events by measuring the position of the outwardly moving front as the CME is initiated

Summary

Introduction

The inner corona is notoriously difficult to study, but it is the region where coronal mass ejections (CMEs) are accelerated. Space-based observations of CMEs using Thompson scattered white-light data are limited to heights above 3.1 RSun, and here CME material usually shows a constant speed or deceleration (Sheeley et al 1999). Measurements in the inner corona can be made using narrowband filter images or X-ray imaging (Alexander et al 2002; Gallagher et al 2003; Reva et al 2017; Seaton & Darnel 2018), but these observations are usually limited to large, rapid CMEs and may be biased by the temperature response of the particular observed radiation. Ground-based observations have been made in white-light (St. Cyr et al 1999; Mancuso 2007) but these are limited by the higher scattered light background produced by the Earth’s atmosphere, and have lower spatial resolution than space-based observations of the region (Elmore et al 2003).

Methods

Discussion

Conclusion