Coronado SolarMax II 60 DS. 16x and 21.5x ( Ha )
First off I notice two active region plages. AR12804 and AR12805. AR12804 is the easiest to see and I can see it's spots within. I can also see AR12803 to the east of AR12804 but it appears to be no more than a mere disturbance. AR12803 is just across the central longitudinal meridian heading into the NW quadrant behind AR12804. AR12805 is in the SW quadrant.
I can see a smattering of filaments in the SW quadrant NE, SW and SE of AR12805. Two are easy to see. I see one prominence on the NE limb.
The mottles are easily seen today.
Astro-Tech AT72EDII w/Altair wedge + 430nm and 540nm filters. 24x, 36x and 72x ( WL )
First off I tried out the Edmund 430nm filter. It's only the second time I have used it. Using it I can see the spots of AR12804 with one showing a visible penumbra. I can also see the granulation. The seeing still falls short of taking full advantage of this short wavelength filter. I can also see the spot of AR12805.
The Baader 540nm Continuum filter does much better. I can see the largest spot in AR12804 indeed does have a penumbra surrounding a ragged umbra. The second largest spot is elongated and also has a penumbra. To their east is a northward curving line of pores. I see one dark pore north of a line bettween the two largest spots. I can see most if not all the spots/pores the SDO continuum image shows in AR12804. I see one small spot in AR12805. I glimpse a tiny single pore in AR12803 though the SDO continuum image shows about 6 of the granule-sized objects. The granulation is visible and is easier than in the 430nm filter. I can hint at the faculae to AR12804.
Unfiltered white light does well too but overall I think the 540nm filter gives the best view.
CCT Test. Lightspectrum Pro on iPhone XR.
Today I decided to try an experiment. To take a Correlated Color Temperature of the solar disc. At work ( GE Current ) we use professional Konica Minolta CCT meters to test the color temperature of our LEDs to make sure they are in spec. I have a CCT meter app on my phone called LightSpectrum Pro that can measure color temperature. Unfortunately it is no where near as precise as the pro meters at work and I use it there only as a backup if our meters/testers there go out of use or fail to work. Unlike the professional ones this phone app cannot be calibrated for luminance so if an object is too bright or too dim it skews the results. But since I don't have one of our Minolta meters at home I thought I would try it. Using the phone app directly at the sun through the phone camera I got a range between 5100-5300 Kelvin. Then I tried it through the telescope. I chose the Orion70 because it has a more white image. The ND3 filter in the Altair wedge is a bit warmer and would skew the reading low. Using the Orion70 which was surprisingly difficult. I had trouble holding the phone still while centering the solar image in the app window at the right distance and then trying to do a screen capture. Annoying to say the least, I finally took the eyepiece out of the diagonal and used the light coming off the diagonal. That helped though getting the meter to settle down and give a constant reading was still difficult. I came up with 5679K. I think the solar color temperature is around 5750 from the ground if I remember correctly.
I won't swear by the accuracy of this but it was an attempt. An experiment.
And my adorable little cat who is always nearby when I observe came to sunbathe!
Carpe Diem!
James
- GONGCerroTololoHa_2-25-21.jpg (614.17 KiB) Viewed 444 times
- SDOHMIc_2-25-21.jpg (973.32 KiB) Viewed 444 times
- AR12804_SDOHMIc_2-25-21.png (366.83 KiB) Viewed 444 times
- Lily Sunbathing!.png (1.43 MiB) Viewed 444 times
- Solar Color Test.png (379.89 KiB) Viewed 444 times
James
can be useful tools in amateur solar research. I have used mine in imaging prominences, imaging white light and now taking the solar color temperature. All behind a telescope of course. I have also imaged the moon, M31 ( central region ) and Jupiter with it ( I got the 4 moons and two main belts! ) Though I haven’t tried it the video capability of the IPhone is impressive. One could probably stack images from it for much better pictures! The phone has a decent but simple image editor and of course it’s internet capable for research 
and SolarChat. 