AR2759 in High Res | HA | April 3rd 2020

[MalVeauX]

Hey all,

AR2759 is lively with a lovely plage and filaments. The umbra of the sunspot is not very large, but it's still a great little dipole with lots of activity going on.

The high resolution data of the AR was captured via 150mm aperture with only an internal sub-aperture D-ERF that is 50mm, just before the filter system inside the focuser. Seeing was pretty good. No issues with tube currents or other local seeing factors. No full aperture D-ERF/ERF was needed and the resolution was realized (0.4"/pixel, F10 on 2.9um pixels).

And here's a lower resolution view, from a double-stack 60mm system at 0.8"/pixel. The interesting thing about double stacks is that it helps showcase the chromosphere features and removes the photosphere features nearly completely, such as sunspots, the visible umbra is a photosphere feature, so when on-band and well tuned, a tight double stack system will show bright plages, dark filaments and all the chromosphere features but without the dark umbra of the sunspot (to a degree, depending on its size, large ones you will see see the area of the umbra, but it will not be very dark). And the double-limb effect will be removed (as one limb is the photosphere).

Earth Scale:

Seeing Data (SSM), was sub-arc-second this morning many times, slowly deteriorated as the morning progressed, but allowed for high resolution imaging.

Equipment:

150mm F8 (Celestron CR150HD) Refractor (Achromatic Doublet) with Baader 1.25x GPC (F10)
Baader 2" Red CCD-IR Block Filter (Serving as internal sub-aperture D-ERF, in the focuser)
PST Etalon + 10mm BF + ASI290MM camera

Solarmax 60mm II DS Etalon + PST Etalon + 10mm BF + ASI290MM

Very best,

[nicoscy]

Beautiful images!!!

[Davey-T]

Good stuff Martin, the new AR arrived at the same time as clouds here but weekend looks hopeful.

Dave

 

[MarkAR]

Glorious detail, well done.

[Rusted]

Superb images as always! 

[Pete Presland]

Beautiful set of images.