AR2759 in High Res & the Full Disc Mosaic | HA | April 6th 2020

[MalVeauX]

Morning all,

It rained yesterday all day, but today was clear so I was able to spend 15 minutes this morning to capture this data under good seeing conditions and good transparency. AR2759 is decaying fast, but still has plenty of activity going on in the chromosphere, so as always, there's always something to see in HA! I particularly love the plage and mottling around AR's in HA and that's my entire appeal. There's a neat filament passing through the poles within the AR. Also, the AR flared a little bit this morning with a class B flare again, that's twice now!

High resolution AR2759 data captured with 150mm refractor operating at F10 with a mere internal 50mm sub-aperture D-ERF (Baader Red CCD-IR Block filter) and the ASI290MM; no full aperture D-ERF needed at all, seeing conditions were sub-arc-second (see my SSM recording, it was routinely in the 0.8" area and lower quite often). This allowed me to do a single recording of 2k frames and stacked 251 of them and still had a sharp image to process. Environment conditions were not a factor, including the observatory walls (painted white) and no internal tube thermal issues, and my OTA is black.

The disc is a mosaic made with a 60mm aperture and a double-stack set of etalons with the ASI290MM, so it required many panels (I did rapid 1k frames and stacked 101 from each) at that FOV, but just to show what can be done with a smaller aperture too.

AR2759 in High Res:

Solar Disc Mosaic:

Seeing Conditions (SSM data), lots of sub-arc-second time. Was imaging for 15 minutes total (most of that time was just doing the mosaic. Also, again to note, I do not use the SSM to trigger, merely to see the seeing conditions and provide a metric with the data to form a relationship between them.

Equipment:

Celestron CR150HD 150mm F8 Achromatic Doublet Refractor with a Baader 1.25x GPC (operating at F10)
Internal Sub-Aperture 50mm D-ERF (2" Baader Red CCD-IR Block Filter) in the focuser
PST Etalon + BF10mm + ASI290MM (high res HA)

ED80 with Solarmax 60mm II DS + PST Etalon + BF10mm + ASI290MM (mosaic HA disc)

Very best,

[AdeKing]

Thanks for those, the first of those whole disc mosaics looks just like what I've been observing visually throughout the day.  Not quite as much of the fine detail visible, but close enough for e to be happy with my rough attempt at a sketch.

Thanks for sharing.

Ade