November 2020


2020-Nov-19

Creating a new online research log.

Solar space elevator (SSE) observation

http://solar.physics.montana.edu/sbrannon/research/sse/slice.gif

Created several new spacetime plots of the full IRIS observation:

http://solar.physics.montana.edu/sbrannon/research/plots/20201119/spacetime_original.jpg

http://solar.physics.montana.edu/sbrannon/research/plots/20201119/spacetime_background.jpg

http://solar.physics.montana.edu/sbrannon/research/plots/20201119/spacetime_bgsub.jpg

The horizontal long-dashed line shows the upper-limit cutoff of the IRIS SJI FOV (i.e. the rightmost side of the leftmost image in the 4-step SJI 1400 Å raster).

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2020-Nov-30

SSE - data analysis

Blob B1

There are several "blobs" of interest during the IRIS observation.  I still need to construct a consistent system for identifying/naming the blobs (B1, B2, ...)  I will be focused today on the obvious first blob, which I will refer to as B1.  B1 is identified in the following spacetime plot:

http://solar.physics.montana.edu/sbrannon/research/plots/20201130/spacetime_zoom.jpg

B1 first appears at ~240 s (first vertical dashed line) and continues to rise until ~460 s (second vertical dashed line), when it is lost as it rises above the solar limb.  This gives a total lifetime of ≥220 s.  From Brannon et al. (2014), I found that the mean free path in the corona is given by

mfp=58.5[km]n9T6\ell_{mfp} = 58.5 [km] \cdot n_{9} \cdot T_{6}
With a coronal sound speed of cs=170[km/s]n9T6c_{s} = 170 [km/s] \cdot n_{9} \cdot T_6, this gives a natural coronal time scale (as a sound transit time) of tcor~0.34t_{cor} ~ 0.34  s.  Thus, B1 survives for ~650 t_{cor}, which is... exceedingly long, in my estimation, for a HD blob unconfined in any other way.

SSE - loop simulations

No notes today.

IRIS calibrations

Ryan emailed me on Nov 24 with a question about a possibly redundant SJI 2832 flat field from 2014-10-09:
http://solar.physics.montana.edu/sbrannon/iris/calibration_files/sjiflat/20141009_SJI_2832_chaeflat_final.fits

Have responded to say I'll check into this.  It seems to have been taken just before a bake-out so maybe was a check on that?  There's no record of it in the MSU IRIS calibration Google Sheet...

FURST group meeting

ZEROTH beam collimator is aligned.

ZEROTH ready for baffles to be installed?  Cappy and Suman will be in lab this week.

Weekly meeting w/ CCK

Perhaps the more relevant time scale for the blob B1 is L/cs, where L is the size of the blob.  This is if the blob is not in pressure equilibrium.

Suppose the blob is in pressure equib.  Then different times scales will be relevant (thermal conduction, etc.)

To-do for this week:

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