CH plume observation, 13-16 March 2018

There was a low latitude coronal hole, with large longitudinal extent, and we obtained observations for the period 13-16 March 2018 at approximately 13-19 UT each day. XRT, SOT and IRIS supported (EIS is no longer operational), and also DST supported.

13-14 March

I used the same target for both days, which was a bright point seen in 171 and 193.

The XRT sequence were:

 XOB #1BE5: HOP266 - CH plumes - Al/Poly(4096ms) - Thin-Be(11571ms)  6s cadence - AEC0 + G-band 1ms + Darks - 1x1 - FOV 256
   03/13 13:03:00 - 03/13 18:59:54 : # HOP 266 - CH with DST.
   03/14 12:47:00 - 03/14 18:56:00 : # HOP 266 - CH with DST.

The SOT sequences were:

HOP 266 CH with DST
   2018/03/13 13:04:00 - 2018/03/13 17:30:00
   SOT pointing: (190,309) tracking at 2018/03/13 13:00:00
     SP08 (0x01f0) Normal Map 3.2x164", 1 side, Q75, repeat 200s at
2018/03/13 13:04:00

HOP 266 CH with DST
   2018/03/14 13:04:00 - 2018/03/14 17:30:00
   SOT pointing: (398,301) tracking at 2018/03/14 12:44:00
     SP08 (0x01f0) Normal Map 3.2x164", 1 side, Q75, repeat 200s at
2018/03/14 13:04:00

The IRIS sequences were:

+0 13:09-19:23     DST coordination [190", 310"]
+0 13:00-18:24     DST coordination with Hinode [397", 301"]

Kevin's notes for the DST/IBIS sequence. 13-March was clouded out (no data).

Our plan for the DST observations is to do high-cadence scans of H-alpha
and Ca II 8542, doing spectral scans of both lines (in intensity only)
with a cadence of about 7 seconds. We will repeat this 20 times, then
stop and do a full polarimetric scan in Fe I 6173, which will take about
40 seconds. This will leave a gap in the chromospheric spectral scans,
but I hope that is okay to have a good measurement of the evolution of
the photospheric field (with a three-minute cadence). Let me know if you
think we should make changes to this scheme.

We will repeat this sequence (20x H-alpha/Ca II 8542, 1x Fe I 6173) as
long as the weather holds. The forecasts look okay for tomorrow, with a
good chance for clear skies. Whether the seeing conditions will be good
is harder to say. The forecast for Wednesday and Thursday is for more
mixed conditions and increasing chance of clouds, so we'll keep an eye
on that.

15-16 March

I chose a weak plume that was quite far towards the limb. There was a "boundary plume" nearby that was brighter, but I thought it was better to observe a pure CH plume.

Page maintained by Dr Peter Young.