HOP 0264

HINODE Operation Plan (HOP)

accepted on

21-aug-2014

HOP No.

HOP title

HOP 0264

Magnetic Structure, Dynamics and Thermodynamics of Prominence-Cavity Systems

plan term

ToO
2014/10/05-2014/10/14

proposer

name :

Jibben, Reeves

e-mail :

pjibben[at]cfa.harvard.edu

contact person in HINODE team

name :

Reeves

e-mail :

kreeves[at]cfa.harvard.edu

abstract of observational proposal

Goal - The goal of these observations is to determine the magnetic structure underlying coronal cavities and their associated prominences. While the observations we are requesting are not direct measurements of magnetic fields, observations of flows (e.g. Schmidt et al 2009) and areas of heating (e.g. Reeves et al. 2012) can give indications about the underlying magnetic field structure. In addition, these observations, along with coronal magnetic field measurements from the Coronal Multi-channel Polarimeter (COMP) at MLSO (e.g. Bak-Steslicka et al. 2013) can be used to provide constraints on magnetic field models that will be constructed using the flux-rope insertion method (van Ballegooijen 2004; van Ballegooijen et al. 2007). Detailed observations of flows in the prominence itself with IRIS can differentiate between models where prominences are formed through cool material collecting in field line dips related to the global flux rope structure, and a more recent model that posits that prominences are formed in tangled fields within current sheets (van Ballegooijen & Cranmer 2010). With IRIS, Hinode, AIA, and COMP we can obtain information about the evolution of the temperature, magnetic field, and dynamics of the prominence, prominence corona transition region, and coronal cavity. These observations will provide the most complete picture of the prominence and cavity system with which to test models of prominence cavities.

Hinode provides the information concerning temperature, density and the dynamics of the cavity and prominence (Schmidt et al. 2009; Reeves et al. 2012; Kucera et al. 2012). We would like to run a HOP based on HOP 114 that includes IRIS data. HOP 114 has produced exceptional data that we are currently working on. Preliminary results were presented at the Spring 2013 AAS meeting (Jibben et al. 2013).

New observations including IRIS would complete the prominence cavity picture by expanding the wavebands to include more lines in the chromosphere and transition region. Additionally, the high spatial and time resolution of IRIS will allow for detailed measurements of the motions in the prominence. This is a powerful combination for studying coronal cavities, flow dynamics and the magnetic field.

Observations should include quiescent prominences that have a well-defined cavity structure at the limb (preferably the west limb) and, whenever possible, eruptive or pre-eruptive cavities.

request to SOT

High-cadence filtergrams in Ca II.
Exposure: 1200 ms
FOV: 108x108, minimum
Binning: 2x2
Cadence: 40 s or less
Program: a program like 0x04d5 (used previously for HOP 248 & 254), with cadence modified to match the available telemetry, can be used. At 30 s cadence, the telemetry usage would be ~1 Gbit in 6 hours.

request to XRT

Thin-Be, Ti-poly, Al-poly filters with longest possible fixed exposures. FOV should
include the coronal cavity. Large FOV (768”x768”) with 2x2 binning.

request to EIS

Please run study: GDZ_PLUME1_2_300_50s (Hop 114 run on 23 Feb 2013) or similar.

Number of runs: Ideally run twice.
EIS Window placement: Center just above the prominence. If no prominence is visible, center above where prominence would be.

other participating instruments

IRIS:
SJI wavelengths - Si IV, Mg h/k; medium line list; large, coarse 16-step raster; 8 sec exposures. The slit should be rolled so that it is parallel to the limb. IRIS OBS ID 3820259488, or similar.

CoMP

remarks

This is a target of opportunity. We ask to observe the cavity over several days
with 4-6 hours of observations. We request the IHOP run between 18-22UT so we can use CoMP data. Given the requested exposure times, the solar disk should be relatively quiet so that XRT's CCD does not saturate (outside the FOV).

Polar crown prominences with cavities are ideal targets.

IRIS should be pointed at the prominence and Hinode should be pointed so that EIS is centered on the cavity.

References:
Bak-Steslicka et al., ApJL, 2013
Jibben et al., AAS Meeting #224, #323.52., 2013
Kucera et al., ApJ, 2012
Reeves et al., ApJ, 2012
Schmidt et al., ApJL, 2009
van Ballegooijen & Cranmer, ApJ, 2010
van Ballegooijen, ApJ, 2004
van Ballegooijen et al., ApJ, 2007