Astrophotography

Solar Images in H alpha, Calcium K and Visible

Most of my solar images have been taken in visible or H alpha , the Baader CaK filter in conjunction with a Herschel wedge provides a relatively “cheap” way of imaging in CaK.

Images in Visible light give detail of the photosphere , which we can consider as the Suns “surface”, above this is the chromosphere, the upper part of which is viewed in H alpha and mid section can be viewed in Ca K wavelengths. (Not quite this simple as there is some overlap, but broadly works this way) The Cak is sensitive to magnetic fields and the stronger the magnetic filed the brighter the image, this gives more detail of the plages around sunspots and more detail of how magnetic field varies in these areas.

After some time setting up a system to image in all 3 wavelengths a fine clear day arrived on Friday 22nd June and I imaged the sunspots and prominences , then went away, which is why I’ve only just finished processing images.

All images were taken using a mono CCD camera : Imaging Source DMK41, the H alpha images were taken using a Coronado PST, the Visual White light images with a Herschel wedge with a ND.3 filter and Baader continuum filter on the camera, using a Skywatcher Evostar 120 refractor. The Cak images were taken with a Baader Cak filter attached to DMK41 and using a Herschel wedge with either a ND.3 or ND 0.6 filter on Skywatcher  ST102 ( for full disc) and / or Skywatcher Evostar 120. All Images were 600 frame avi’s stacked in AutoStakkert, wavelets tweaked in Registax 6 and final processing in Photoshop CS6. Not having imaged for a while I soon realised that I needed to do some cleaning before the next session as the “dust bunnies”  were more numerous than usual, luckily I was either able to manipulate image to avoid most of them or eliminate them in processing.

I have left the images as mono as features show up better for comparison rather than processing in false colour.

Whole disc in CaK and H alpha, no prominences visible in CaK.

 

 

 

 

 

 

 

 

 

 

 

 

 

Main surface features in Cak in Evostar 120, left to right : faculae, AR2715, AR2713

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Faculae in Halpha x2 barlow

 

 

AR2715 In Cak, Vis,  H alpha (x2 Barlow)

 

 

 

 

 

 

 

 

AR2713 in Cak, Vis , H alpha (x2 Barlow)

 

 

 

 

 

 

 

 

Prominences x2 Barlow

 

 

 

 

 

Moon and Venus 15/07/18

Now 2 days old the moon at 11% illumination presented it self in the evening sky at an elevation of approx. 12 degrees at 21:30, easily visible, unlike yesterday when I could only pick it out using binoculars.

Its companion this evening was Venus, easily visible unlike mercury of the previous evening. Didn’t have to travel any further than front lawn for these shots.

Planets and planetaries – – -14-15/07/2018

Here are some images from last night.

Having been seriously impressed with Neil’s planetary images, i have an ADC on order!

Meanwhile, I had another go at Saturn last night. Had it not been for Neil’s images, I would have been quite pleased with this one! Best I’ve managed this apparition!

I then did a composite exposure of the visible moons.

While waiting for Mars to rise to an appropriate position, I vistited these 2 planetary nebulae, NGC 6818 in Sagittarius and NGC 6781 in Aquila.

Eventually, Mars became visible,and I tried this image, bearing in mind Mars’s altitude was only about 11 degrees. As I’m sure you know, Mars is currently covered by a dust-storm, hence the lack of visible surface detail.

There did seem some vague hint of detail so here is the image with an extreme contrast stretch, followed by a screenshot of Mars from “Stellarium” for comparison. (Stellarium shows an accurate depiction of the surface facing us – a useful resource)

 

 

Can’t wait for the ADC to arrive!

 

Day old moon (and Mercury?????)

The day old moon was setting on the 14th July with mercury in close attendance, well I went to my usual spot for these events, set up Canon 450D on tripod with cable shutter release and 150-500mm Sigma zoom lens. Sunset well into the NW around 21:30 then patiently scanned horizon in W to WNW direction with 7×50 binoculars for sign of moon which was going to be a thin crescent of approx 3.4%. The more worrying feature was a low cloud bank across the horizon ( see Andys previous post to this) which made for a glorious sunset but was going to cause problems trying to view Mercury and in fact as mercury was about 1-2 degrees to left of moon and about 2 degrees below it never punched through the murk. First image of moon was at 21:46 and last at 22:06 as it slipped into the cloud bank.

1.F6.3,ISO1600, 1/500″, 500mm

2. F5.6, ISO1600, 1/1250″,289mm

3. F6.3,ISO 1600, 1/400″, 500mm

4. F6.3, ISO1600, 1/30″, 150mm