AR2760 and the Cycle 25 AR | HA, CaK, WL | April 27th 2020

[MalVeauX]

Heya,

Well, it's been a hot minute. I've had a dreadful series of storms and I've been in and out of quarantine at the hospital (it's my day job) so I've been out of comission for quite a while. It was painful to miss that prom a week ago. Anyhow, today was clear for the first time in what I think might be two weeks, and there's two active regions, so I'll take it! Seeing was decent, not great today, a cold front passing through. I managed to get enough data to do the photosphere and the chromosphere in CaK & HA of our two AR's in moderate resolutions as seeing deteriorated rapidly after 0930am for me, so I started at 150mm aperture and then moved towards 120mm and settled there for the rest and then a little peak in the 60mm to finish it off. I did some visual too from a new pier I built (had to do something during the bad weather) near my observatory for when my imaging setup is busy. The two AR's looked great in the double stack 60mm and there's a rather big prominence on the limb near them, fan shaped, but it was pretty dim despite it's size. The two AR's have visible umbra's and are both dipoles. The bigger one is cycle 24, she's still kicking apparently, so we're still in the minimum of course. The other AR (unnamed?) is cycle 25. Interesting to see the polarities side by side like this! The Cycle 25 is a very obvious dipole with two spots and hot chromosphere material arching between the poles despite being smaller.

Color:

B&W:

Seeing Conditions (sub-arc early on, so I was able to fully realize the 150mm's resolution, but it deteriorated rapidly within the hour so I dropped to 120mm aperture then 60mm aperture)

Equipment:

150mm F8 Frac + Baader Red CCD-IR Block Filter (2" internal sub-aperture D-ERF) + Baader 1.25x GPC (F10)
PST Etalon + 10mm Blocking Filter + ASI290MM (HA)

120mm F10 Frac (Above masked) + Baader Red CCD-IR Block Filter (2" internal sub-aperture D-ERF)
Baader 3.0 ND Filter + ASI290MM (Photosphere, Red Wavelength)

120mm F10 Frac (Above masked) + Baader Blue CCD-IR Block Filter (2" internal sub-aperture D-ERF)
Lunt CaK B1200 + ASI290MM (CaK)

ED80 Frac + SolarMax 60 II Etalon (F10) + PST Etalon + 10mm Blocking Filter + ASI290MM (HA)

Very best,

[Pete Presland]

Superb set of images!