Date/Time: 4 hours either on 14th or 15th of February ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joint Observing Proposal: High Cadence Multi-Wavelength Study of Quiet Sun Supergranular EUV Brightenings
Involved: Scott W. McIntosh [HAO/NCAR - Lead], Davina Markiewicz-Innes [MPS-Lindau]
Update History First Draft (22 January 2009)
Participating Instruments and Observatories SOHO/EIT [Kevin Schenk; Joe Gurman] STEREO/SECCHI [Simon Plunkett] Hinode/SOT [Bruce Lites; Ted Tarbell]
Scientific Objectives & Justification: Our objective is to study the spectrum of EUV brightenings in the quiet sun that are related to the relentless evolution of the quiet sun magnetic field on the supergranular scale near-simultaneously in two passbands. The observed brightenings relate to the formation and destruction of EUV brightpoints as well as the persistent advection of magnetic flux toward the network boundaries/vertices that have been connected to phenomena such as macro-spicules, explosive-events [McIntosh 2007a, 2007b] and most-recently small-scale CMEs [Innes et al. 2008]. STEREO/SECCHI observations offer us an unprecedented opportunity to study such brightenings at two wavelengths [in the transition region/low corona at 304A and in the 1MK corona at 171A] simultaneously prior to the launch of SDO. The temporal phasing and co-spatiality of the observed brightenings and small-CMEs will be coordinated through the novel analysis of the observed light-curves in the overlapping region of the spacecraft [McIntosh 2007a, 2007b]. EIT, in 304A, will offer regular cadence observations of the STEREO overlap region and the potential of stereoscopic imaging between the three spacecraft. High resolution magnetic information will be provided for the overlapping target region by SOT/NFI and SP. In this way we will be able to investigate the high-sensitivity magnetic field measurements at the root of the small-scale EUV observed.
Supporting Publications: McIntosh, S.W., 2007a, "Does High Plasma- Dynamics ``Load'' Active Regions?", ApJ, 657, L125 McIntosh, S.W., 2007b, "On the Mass and Energy Loading of Extreme-UV Bright Points", ApJ, 670, 1401 Innes, D.E., 2008, "Quiet Sun mini-CMEs activated by supergranular flows", [http://adsabs.harvard.edu/abs/2008arXiv0811.2744I], in press A&A
Expected Duration: Minimum of 4 hours [significant fraction of supergranular lifetime]
Pointing: Only SOT requires pointing information - expecting a disk center target
Instruments & Measurements Required:
STEREO/SECCHI/EUVI [A & B] - A: 171A high cadence [2 minutes] - B: 304A high cadence [2 minutes] SOHO/EIT - 304A high cadence [7 minutes] - Requires sub-mode change? Hinode/SOT - NFI: Fe I 6301.5A IV/DG [Full FOV; 2x2 binning; 1 minute cadence] - SP: IQUV large map overlapping SOT FOV; 3 s/slit; 2x2 binning; 0.3" px size
|
|