Tuesday, 30 June 2020

Trials and tribulations of imaging M16 from a suburban observatory

Click on an image to get a closer view.

This image reveals the narrow time slot I have for imaging M16. I have an imaging window of about 16 degrees, that is, about 50 minutes of imaging time.


This is a single, 60s sub-frame of M16 rising above the rooftop. The camera was set on 2 times bin mode to increase the sensitivity of the camera.


This image of M16 is a composition of R,G,B colour data with narrowband luminance data


I was using my 80mm refractor at f/6.3, a Vixen Atlux mount and an Atik 383L mono CCD camera. The data for this image were captured on three seperate evenings. On the first evening I captured 5-minute subframes with matching dark-frames and combined them with flat fields with the camera set to times one bin mode. I captured three sub-frames for each narrowband filter SII, OIII and H-alpha.

On the second evening I set the camera to times two bin mode to increase the sensitivity of the camera using a H-alpha filter for luminance.

On the third evening I captured 30 minutes using a SII filter, and 25 minutes using a OIII filter using 60s sub-frames.




This image is a composition of data taken from three different telescopes, a 10" reflector, a 4 " refractor, and an 80mm refractor.


This is an image of M16 taken with a 10" reflector with colour data obtained with an 80mm refractor


Sunday, 21 June 2020

M64, the Black eye galaxy

I captured this image under moonless sky conditions with stars visible down to magnitude 4.6. I was using an 80mm, f/6.3 refractor with a Vixen Atlux mount, PHD autoguiding and an Atik 383L mono CCD camera.

I captured ten-minute sub-frames with matching dark frames, and flats to remove the effect of vignetting in the final image.

The total exposure times were 60 minutes for each filter, H-alpha, SII and OIII. I sued H-alpha for Red, SII for green and OIII for blue.

Click on an image to get a closer view

M64

Cropped

Thursday, 18 June 2020

M44 The Beehive Cluster

This iamge was taken with my 80mm refractor, a Vixen Atlux mount, PHD autoguiding and an Atik 383L mono CCD camera.

I captured ten-minute sub-frames with matching dark-frames, and combined them with flat-field frames to reduce the effect of vignetting in the final image.

The total exposure times were 20 minutes using a H-alpha filter, 10 minutes using a SII filter and 20 minutes using an OIII filter. I used H-alpha for the red channel, SII for the green channel and OIII for the blue channel.

M44

Wednesday, 17 June 2020

M13

This image was captured under a Full moon with very clear sky conditions.

I was using a Vixen Atlux mount, an 80mm refractor at f/6.3, PHD autoguiding and an Atik 383L mono CCD camera.

I captured five minute sub-frames with matching dark-frames and combined them with flat-field frames to reduce the effect of vignetting in the final image.

The total exposure times were 60 minutes for each filter, Ha, OIII and Blue.

M13

Closer view

Friday, 12 June 2020

Simple way of adding diffraction spikes to images taken by refractors.

Crossed wires in front of the objective cause diffraction spikes in the image.


M87 and Markarion's Chain

This image of M87 was taken under moonless conditions with only light-pollution to contend with. Stars were visible down to magnitude 4.8

I was using my 80mm, f/6.3 refractor, an Atik 3.83L mono CCD camera, a Vixen Atlux mount with PHD auto-guiding.

I captured 5-minute subframes with matching dark-frames and combined them with flat-field frames to reduce the effect of vignetting in the final image.

The total exposure times were 60 minutes using a H-alpha filter, 60 minutes using an OIII filter and 90 minutes using a blue filter.

M87


This image of Markarion's chain is a reprocessed image with an extra 90 minutes of luminance data added using a blue filter.

Markarion's chain

Mosaic composition of the Markarion chain with M87


Thursday, 30 April 2020

M97 and M108

This image was taken using an 80mm f/6.3 refractor on a Vixen Atlux mount.
PHD autoguiding was used with an Atik 383L mono CCD camera and a set of Astronomik filters.

10 min sub-frames were captured with matching dark-frames. Flat-fields were used to reduce the effect of vignetting in the final image.

The total exposure times were 20 min using a SII filter, 20 min using an OIII filter and 90 min using a H-alpha filter.

M97 and M108

Closer view

Tuesday, 28 April 2020

Markarian's Chain

This image was taken under a moonles sky with only light-pollution to contend with.

An 80mm, f/6.3 refractor was used on a Vixen Atlux mount, with PHD autoguiding, an Atik 383L mono CCD camera and a set of Astronomik filters.

Ten-minute sub-frames were captured with matching dark-frames and flat-fields were used to reduce the effect of vignetting in the final image.

The total exposure times were 30min using an OIII filter, 30min using an SII filter and 90min using a H-alpha filter, plus 3 hours using a blue filter.

Markarian's Chain

Closer view

Sunday, 26 April 2020

The Leo Triplet

This image was taken using narrowband filters, H-alpha, SII and OIII. The telescope I was using was an 80mm, f/6.3 refractor.

The scope was mounted on a Vixen Atlux mount. PHD autoguiding was used and the images were captured with an Atik 383L mono CCD camera and a set of Astronomik narrowband filters.

10 min sub-frames were captured with matching dark-frames and they were combined with flat-field frames to reduce the effect of vignetting in the final image.

The total exposure times were 60 min for each filter.

The Leo Triplet

Closer view

Wednesday, 22 April 2020

NGC 1499, The California Nebula

This image was taken using an 80mm, f/6.3 refractor mounted on a Vixen Atlux mount.
PHD autoguiding was used with an Atik 383L mono CCD camera and a set of Astronomik narrowband filters.

The total exposure times were 60 min using an OIII filter, 60 min using a SII filter and 3 hours using a H-alpha filter.

ten minute sub-frames with matching dark frames were captured and they were combined with flat-fields to reduce the effects of vignetting in the final image.

NGC 1499 bi colour

Closer View


NGC 1499 RGB narrowband luminance

Closer View


NGC 1499 Hubble Palette

Closer View


NGC 1499 Hubble Palette plus RGB

Closer view