Solar Activity 16 Sep

[brianb]

A better day, still showery & with a strong wind, but more clear sky and the wind has shifted far enough round to the north for my observing site to be sheltered by my house, allowing the FLT 110 to be used - though with lots of trouble with wind vibration, which is causing a delay in processing some of the surface shots. I'll post the missing images later.

The Sun's activity continues

1055 UT. Coronado PST CaK, prime focus, DMK41

1059 UT. Solarscope 60, 0.5x focal reducer, DMK41

There are tall, brightish and fairly active prominences in the south east

WO FLT 110, Solarscope SF-100 Ha filter set, 2.5x Powermate, DMK21

and in the north west

WO FLT 110, Solarscope SF-100 Ha filter set, 2.5x Powermate, DMK21

AR 11106 continues, apparently little changed

1108 UT. WO FLT 110, Lunt solar wedge, 2.5x Powermate, DMK21

1115 UT. WO FLT 110, Lunt B1200 CaK diagonal, 2.5x Powermate, DMK21

A new active area is rotating into view in the south east. There is associated chromospheric / lower coronal "spiking" associated with this AR:

1109 UT. WO FLT 110, Lunt solar wedge, 2.5x Powermate, DMK21

1118 UT. WO FLT 110, Lunt B1200 CaK diagonal, 2.5x Powermate, DMK21

1304 UT. WO FLT 110, Solarscope SF-100 Ha filter set, 2.5x Powermate, DMK21 (two frame mosaic)

Transparency good between showers. Seeing fairly good with only light boiling, but much troubble from wind vibration. Temperature 14C, wind N force 5-6.

[hunterknox]

A stunning set. I particularly like the white light version of the emerging sunspot. Well done, as ever!

[sheri_barri]

Great set yet again Brian. I have to second the vote on the white light capture of the emerging sunspot. The detail and clarity at such a sharp angle is stunning! Nice work!

[brianb]

UPDATE:

Here are some Ha surface images - WO FLT 110, Solarscope SF-100 Ha filter set, 2.5x Powermate, DMK41 - all at 0.8x scale

NE sector filaments, 1255 UT:

NW sector filament, 1253 UT:

AR 11106, 1248 UT:

New AR, SE sector, 1246 UT:

Also improved white light closeups, WO FLT 110, Lunt solar wedge, 4x Imagemate, DMK21:

AR 11106, 1332 UT:

New AR, SE sector, 1335 UT:

[GuillermoBarrancos]

Nice! That new emerging sunspot is going to be interesting for sure!

[sheri_barri]

The emerging sunspot on the H-alpha close-up practically crackles! Nice one!

[beamish]

Great set of pics Brian. That emerging spot is the one I was trying ( abysmally) to image yesterday, might try again today if the clouds stay away.

Brian can you make any suggestions regarding improving white light imaging ? I want to use the F15 Mak & the Lu cam for some close up shots. Can any of the RGBL or IR filters be utilised to help

[jgs001]

Very nice set Brian... excellent work. That new region looks interesting..

[brianb]

Brian can you make any suggestions regarding improving white light imaging ?

Assuming your scope has minimal chromatic aberration, your main enemy is the seeing - and you beat seeing by getting the exposure short. Extra filters don't help that. I'm using the Lunt solar wedge plus the mandatory ND 3.0 filter only & getting an exposure typically around 1/2000 sec at f/28 with moderate gain. The "visual" ND 5.0 solar film is really a bit too dense for imaging, changing to the ND 3.8 will shorten the exposures 16 fold ... but is dangerous to use visually without extra filtering.

If you do have chromatic aberration a green filter will probably help when used with a monochrome camera. The Baader solar continuum filter is best but an ordinary deep green (Wratten #58) works well. However, you'll still be handicapped compared with people using a filtering system that passes more photons.

Shoot lots & lots of frames & stack only a small proportion. 400 from 2000 with moderate gain is typical for me, 500 from 3000 with higher gain when the seeing is unsteady.

[beamish]

Cheers Brian, I'm aware that white light imaging (via Baader solar film) isn't ideal and has limitations , I'm merely wishing to max' it's potential with what have.

The seeing yesterday was JUST horrendous, and that was when there weren't clouds !

There's no CA with the mak and the cam is certainly up to the job. Just getting it together now for another viewing/imaging ?