The Solar Coronal Dopplerometer (SCD)

Lead Research Organisation: Queen's University of Belfast
Department Name: Sch of Mathematics and Physics

Abstract

After some 60 years of research, the specific agent involved in the heating of the solar corona has still not been definitively identified. Basically, the chief mechanisms that have been theoretically studied fall into two categories: (a) heating due to numerous small magnetic reconnection events (nanoflares) in magnetic flux tubes resulting from photospheric motions; (b) dissipation of Alfvén or magnetohydrodynamic (MHD) waves in coronal loops, or more probably tiny strands making up loops. Over the past few years, there have been many studies of wave motion and possible heating mechanisms in the solar atmosphere, by researchers at Queen's University Belfast (QUB) and elsewhere. One of particular relevance is that with the Coronal Multi-channel Polarimeter (CoMP) at the Sacramento Peak Observatory's coronagraph. Although no intensity variations were detected by CoMP in the Fe XIII 1074.8 nm line, velocity variations were observed over the entire area of a coronal active region and at all times during a 9-hour observing period. The waves were upward-propagating, with low frequencies, their distribution peaking at 3.5 mHz (period of about 5 minutes). However, the energy flux of these waves amounts to only about 0.1 W per square metre, and so appears to be insufficient for a coronal heating role which requires an energy flux of about 100 W per square metre.

Searches for much higher-frequency waves, or more accurately visible-light intensity oscillations, have been made since the 1980's during the brief time period afforded by total solar eclipses (< 6 minutes; typically 1 - 2 minutes), when the corona is better observed than with a coronagraph. The corona has been imaged using narrow-band filters in the Fe XIV green line at 530.3 nm, or occasionally the lower temperature Fe X red line at 637.5 nm. These experiments have provided some evidence of significant oscillatory power with periods ranging from 1 - 27 seconds. The shorter periods are of particular interest snce theoretical work suggests that high-frequency (~ 5 Hz) waves in coronal loops dissipate readily at typical coronal densities, and that the energy conveyed may (if the magnetic fields are not very large) balance the energy losses of the corona.

In the present proposal, we seek funds to construct a new instrument - the Solar Coronal Dopplerometer (SCD) - to be deployed during the 21 August 2017 total eclipse of the Sun that will be visible over a track crossing the continental USA. However, the SCD will not search for intensity fluctuations in the corona, but rather material moving along coronal loops as revealed by Doppler shifts in the Fe XIV 530.3 nm and Fe X 637.5 nm coronal lines, as detected by the CoMP in Fe XIII 1074.8 nm on much longer timescales.

The SCD is a collaborative project involving QUB, Prof K Phillips (Honorary Professor at both QUB and Scientific Associate at the Natural History Museum), plus teams from the University of Wroclaw (Poland) and Observatoire de Paris Meudon (France). Their responsibilities to the SCD project are: Phillips - organise and lead eclipse observing campaign to USA; Wroclaw - provision of detectors, telescope and heliostat; Meudon - staff costs for SCD assembly; QUB - the component costs.

Planned Impact

The project represents an opportunity for significant publicity and outreach activities. Our previous eclipse campaigns between 1998 and 2001 generated a lot of positive publicity for the funding participants, including QUB and PPARC. We believe this would also be the case for a campaign in the USA in 2017 (plus possible future eclipses).

Publications

10 25 50
 
Description This grant is to fund the development of an instrument to observe the total solar eclipse in the US in August 2017. Hence there are no outputs to date. However, we did discuss with the BBC and other media about covering our eclipse campaign in the US. Unfortunately this did not happen, so instead we made our own video recording of our eclipse campaign. We plan to develop this as a talk for the public and schools.
First Year Of Impact 2016
Sector Education
Impact Types Cultural,Societal

 
Description Astronomy Research Grants
Amount £1,307,461 (GBP)
Funding ID ST/P000304/1 
Organisation Science and Technologies Facilities Council (STFC) 
Sector Public
Country United Kingdom
Start 04/2017 
End 03/2020
 
Description Annual in-house activities 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Schools
Results and Impact Astronomy lectures and presentations are given at the following annual events: (i) QUB Horizons in Physics} (which attracts around 400 4th- and 5th-form students per year), (ii) Physics Open Days (around 200 6th-form students), (iii) Physics Teachers Conference (about 50 Physics teachers from schools in Ireland).


Increased take-up of Physics and Astronomy degree programme over last 3 years.
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017
 
Description Links with W5 Discovery Centre 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Schools
Results and Impact An ongoing partnership with the W5 Discovery Centre in Belfast (Ireland's award-winning science and discovery centre). We developed the Planet Quest exhibition, based on explaining the multi-wavelength nature of modern astronomy. This includes spectacular infrared images from telescopes and satellites, information stands on the nature of infrared radiation, and hands on activities for children. It showcases high-profile Queen's astrophysics research to illustrate to the public that world-leading, technology-driven research is happening in Belfast. The exhibition initially ran March - September 2012, attracting 10,000 visitors, and we hope to run it again during the period 2014 - 2017. Astrophysics staff also host talks, Q&A sessions and hands-on building games in W5 (aimed at Key Stage 3 pupils), and further support W5 through the creation of astronomy CPD materials and a centralised web resource for secondary school physics teachers.

Increased interest in astronomy and science from schoolchildren.
Year(s) Of Engagement Activity 2012,2013
 
Description Michael West lectures 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact We have initiated a series of high-profile public lectures, The Michael West Lecture Series in Astronomy, following a philanthropic donation from Dr West which funds a Fellowship with a major outreach and education component. These lectures, which are scheduled typically twice per year, each attract 200 people, and are now the most widely attended public lecture series at Queen's University and indeed in Ireland as a whole.


Increased requests for e.g. school talks. Media interviews.
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015,2016,2017,2018
URL https://star.pst.qub.ac.uk/wiki/public/outreach/start
 
Description Presentations on the total solar eclipse in the USA in 2017. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact During our campaign to observe the total solar eclipse in the USA in 2017, we gave talks and demonstrations to audiences at the eclipse site in Idaho. We have also made a video of the eclipse campaign, and plan to develop this into a talk for schools and the general public.
Year(s) Of Engagement Activity 2017
 
Description School visits 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact All members of the Astrophysics Research Centre (ARC) at Queen's University are involved in schools talks, covering their research topics as well as more general interests in astronomy. Most are at secondary level but also at primary (we actively take part in STEPS), either in the classroom or at Queen's. ARC staff deliver a total of about 40 talks/year to pupils, with typical class sizes of 25.

Hard to assess, but in Northern Ireland uptake of Physics at university level has increased steadily in recent years, in contrast to the UK trend.
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017,2018