The Jellyfish Nebula (IC443)


The Jellyfish Nebula is an expanding bubble-shaped cloud of debris from a massive star that exploded over 30,000 years ago.  The nebula is about 5,000 light-years distant in the constellation Gemini.  It is a faint and elusive object but is captured here using the technique of emission line imaging using Hydrogen Alpha (Ha) and Oxygen III narrowband filters.  The image is a Ha-OIII-OIII false colour composite with an added luminance layer created from the first component of a Principal Component Analysis (PCA) of the multiband image.

Right ascension: 06h 17m 31.71s | Declination: +22° 39' 45.3" | Distance: 5,000 Light Years
Field of view: 42 x 28 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Mount: 10Micron GM1000 HPS
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 8 x 30 min, OIII 22 x 30 min
Total exposure: 15 hours
Scale: 1.15 arcsec/pixel
Image acquired: 5 nights over the period January – March 2016

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; PixInsight v1.8 Deconvolution; ImageJ v1.51j8 PCA; Photoshop CC 2014

Pickering’s Triangle in Ha-OIII

Part of the larger Veil Nebula complex, these glowing filaments of ionised hydrogen are the result of shock waves from a massive supernova explosion estimated to have occurred around 5,000 years ago.  The original Ha image was taken over three nights in October 2015 and then supplemented with additional Ha and OIII data collected over six nights in September 2016.  Both sets of images were acquired from my observatory in Somerset.

Right ascension: 20h 48m 21s | Declination: +31° 29' 24" | Distance: 2,600 Light Years
Field of view: 42 x 28 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Mount: 10Micron GM1000 HPS
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 22 x 20 min, OIII 18 x 20 min
Total exposure: 13.3 hours
Scale: 1.15 arcsec/pixel
Image acquired: October 2015 and September 2016

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; PixInsight 1.8 Deconvolution; Photoshop CC 2014

Widefield view of Heart Nebula (IC1805)

IC 1805 is a massive 300 light year cavity of excavated gas blown out by the stellar winds and ultraviolet radiation of a cluster of hot OB stars at its centre.  The cluster is positioned some 50 light years in front of the nebula it illuminates.  Wide field images such as this reveals IC 1805's delicate silhouette from which it derives its popular name – the Heart Nebula.  The nebula is located about 7,500 light years away toward the constellation of Cassiopeia.  At the top left is the companion Fishhead Nebula.

Right ascension: 02h 33m 40.9s | Declination: +61° 23' 30.8" | Distance: 7,500 Light Years
Field of view: 234 x 176 arcmin

Camera: QSI 583wsg
Optics: TS Photoline TS60ED F/4.3 APO with Photoline x0.79 reducer
Guiding: Off-axis with Lodestar guider
Filters: Baader Ha (7nm), OIII (8.5nm)
Exposures: Ha 18 x 20 min, OIII 17 x 20min
Total exposure: 11.7 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 4.2 arcsec/pixel
Image acquired: Over seven nights between 25th September 2015 and 13th March 2016.

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL, Straton and Photoshop CC 2014

Melotte 15 at the heart of the Heart Nebula (IC1805)

The open star cluster at the centre of this image is known as Melotte 15 and is embedded within a central portion of the much larger glowing nebula known as the Heart Nebula.  The gnarled structure is a massive area of glowing ionised hydrogen where dust and gas clouds are sculpted by the intense pressure of the solar wind and ultraviolet radiation from the massive hot stars making up the Melotte 15 cluster.

Poor weather across Britain during autumn and winter 2015 meant there were few clear nights and it has taken over 6 months to acquire 23 hours of Ha and OIII data.  Note that I am now taking 30 minute exposures with the 10Micron GM1000 HPS in combination with active optics guiding consistently delivering perfectly round stars.

Right ascension: 02h 33m 41s | Declination: +61° 23' 31" | Distance: 7,500 Light Years
Field of view: 42 x 28 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Mount: 10Micron GM1000 HPS
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 24 x 30 min, OIII 22 x 30 min
Total exposure: 23 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 1.15 arcsec/pixel
Image acquired: Over 7 nights between 25th September 2015 and 13th March 2016

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; PixInsight Deconvolution, Photoshop CC 2014, Color Efex Pro

New 10Micron GM1000 HPS equatorial mounting

I have been operating the 10Micron GM1000 HPS mount with my APM 6 inch refractor since beginning of November 2015.  It is a superbly well engineered and extremely accurate mount.  Building a sky model and polar aligning the mount are straightforward tasks and I achieved very accurate results with minimal effort on first attempt.  I am very pleased to have retired the AZ-EQ6 GT which was driving me mad with mediocre tracking and undiagnosed driver/USB connection issues causing occasional loss of synchronisation with the ACP pointing model.  The GM1000 is in a different class with a price tag to match but I am now able to just concentrate on imaging and the only limiting factor is sky quality.

Many users of this mount take advantage of its extreme accuracy to abandon guiding however I am currently using active optics guiding with a Starlight Xpress SXV-AO-LF unit.  As tracking error will be minimal the premise is that it may be possible to correct for residual fluctuations due to atmospheric turbulence (seeing).  I will be conducting experiments with and without AO guiding to see if I can gather any evidence to support this proposition.

NGC 7635 The Bubble Nebula

The Bubble Nebula is a shell of gas surrounding a massive O star (BD+602522) which can be seen in the upper right quadrant of the bubble.  The star is several hundred thousand times more luminous and around 45 times more massive than our Sun.  A fierce stellar wind and intense radiation from the star ionizes the shell causing it to glow.  The expansion of the bubble is contained by the surrounding giant molecular cloud.  About six light-years in diameter, the Bubble Nebula is located in the direction of the constellation Cassiopeia.

As there was barely sufficient OIII data to produce a colour image, a false colour RGB image was created using the bicolour processing technique and then the Ha image was recombined as the luminance channel.  This allows colour noise reduction, elimination of star halos and Gaussian smoothing prior to adding the Ha luminance layer.  The final image was selectively smoothed, sharpened and colour enhanced using Photoshop and Color Efex Pro.

Right ascension: 23h 20m 45s | Declination: +61° 10' 31" | Distance: 11,000 Light Years
Field of view: 42 x 28 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 15 x 20 min, OIII 16 x 20 min
Total exposure: 10.3 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 1.15 arcsec/pixel
Image acquired: Over 4 nights between 27th August – 18th September 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; Photoshop CC 2014, Color Efex Pro.

Wide-field image of IC1318 in Cygnus


The bright star projected at bottom centre of this image is the supergiant Gamma Cygni (aka Sadr). It is located only 750 light years away and so is not directly associated with the vast emission clouds of the Cygnus complex which are much more distant at 5,000 light years. Above Gamma Cygni and shaped like two luminous wings divided by a long dark dust lane is the nebula complex IC1318 commonly referred to as the Butterfly Nebula.

This image was obtained with my TS60ED F/4.3 APO refractor and illustrates what a great instrument it is for acquiring deep wide-field images of extended objects.

Right ascension: 20h 27m 13.1s | Declination: +40° 09' 27.8" | Distance: 5,000 Light Years
Field of view: 234 x 176 arcmin

Camera: QSI 583wsg
Optics: TS Photoline TS60ED F/4.3 APO with Photoline x0.79 reducer
Guiding: Off-axis with Lodestar guider
Filters: Baader Ha (7nm), OIII (8.5nm)
Exposures: Ha 21 x 20 min, OIII 21 x 20min
Total exposure: 14 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 4.2 arcsec/pixel
Image acquired: Over seven nights between 30th July and 18th September 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL and Photoshop CC 2014

IC1396 – Combined Ha and OIII bicolour composite

This is a colour enhanced version of the Hydrogen Alpha image of IC1396 in Cepheus acquired on 17th July 2015.  The image is made up of an additional four hours of Ha data and combined with 6 hours of OIII using the Cannistra Modified Bicolour Narrowband Technique.

Right ascension: 21h 39m 55.3s | Declination: +57° 36' 48.8" | Distance: 2,400 Light Years
Field of view: 234 x 176 arcmin

Camera: QSI 583wsg
Optics: TS Photoline TS60ED F/4.2 APO with Photoline x0.79 reducer
Guiding: Off-axis with Lodestar guider
Filters: Baader Ha (7nm), OIII (8.5nm)
Exposures: Ha 17 x 20 min, OIII 19 x 20min
Total exposure: 12 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 4.2 arcsec/pixel
Image acquired: 17th July and four nights between 27th September – 3rd October 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL and Photoshop CC 2014

IC1318 - Butterfly Nebula (Part B)

IC1318 is a giant HII cloud and one of the brightest among all the emission clouds in the Cygnus complex.  The cloud is bisected by a thick obscuring dust lane to create two parts that have been compared to the wings of a butterfly which has led to its popular name.  This image shows detail of the dark smoke-like whorls of dense dust and gas that obscure the bright nebulosity of the northern wing (Part B) of the Butterfly Nebula.

Right ascension: 20h 24m 55s | Declination: +40° 33' 25" | Distance: 5,000 Light Years
Field of view: 42 x 28 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Filters: Astrodon Ha (3nm), OIII (3nm)
Exposures: Ha 17 x 20 min, OIII 19 x 20 min
Total exposure: 12 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 1.15 arcsec/pixel
Image acquired: Over 5 nights between 2nd July – 8th August 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; Photoshop CC 2014

Fleming’s Triangular Wisp (aka Pickering's Triangle)

Part of the larger Veil Nebula complex, these glowing filaments of ionised hydrogen are the result of shock waves from a massive supernova explosion estimated to have occurred around 5,000 years ago.  The nebula was discovered photographically by Williamina Fleming in 1904 but following the custom of the day the find was credited to her superior Edward Pickering, director of the Harvard College Observatory, and catalogued as NGC 6979.

The image was taken over three nights in October 2015 from my observatory in Somerset with my APM six inch refractor operating at its native focal ratio of F/7.9.

Right ascension: 20h 48m 21s | Declination: +31° 29' 24" | Distance: 2,600 Light Years
Field of view: 42 x 28 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/7.9
Guiding: Starlight Xpress Active Optics SXV-LF-AO
Filters: Astrodon Ha (3nm)
Exposures: Ha 14 x 20 min
Total exposure: 4.6 hours
Scale: 1.15 arcsec/pixel
Image acquired: 2nd, 3rd & 7th October 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; Photoshop CC 2014

NGC 1491 | SH2-206 – an emission nebula in Perseus

NGC 1491 (also designated Sharpless SH2-206) is a bright emission nebula and HII region, located on the edge of a vast cloud region of neutral gas, about 10,700 light-years away in the Perseus arm of our Milky Way galaxy.  The stellar wind from the O5V 11.2 magnitude star (BD +50 886) at its centre is forming a blister in the gas clouds immediately surrounding it while also eroding the gas clouds.

HII regions are well known for being places where new stars are born, and are created when ultraviolet radiation from hot stars ionizes the surrounding gas, causing it to glow in visible and infrared light.  This is a faint nebula and required over nine hours of integration time at each emission line to reveal the detail across the entire nebula.

MaxIm DL v6 was used to calibrate, align and stack the sub exposures.  PixInsight v1.8 DBE (Dynamic Background Extraction) was used in the absence of suitable flat frames to remove sky background noise and gradients.  Photoshop CC 2014 layers and layer mask processing techniques were used for colour enhancement and to tease out the detail – Levels, Curves, Reduce Noise, Selective Color, HDR toning, Smart Sharpen and Unsharp Mask in predominant use.

Right ascension: 04h 03m 14s | Declination: +51° 18' 58" | Distance: 10,700 Light Years
Field of view: 54 x 37 arcmin

Camera: SBIG ST-10XME
Telescope: APM 152-1200ED F/6.2 with Riccardi x0.75 Reducer
Guiding: Off-axis with Lodestar guider
Filters: Astrodon Ha (3nm), OIII (3nm), SII (3nm)
Exposures: Ha 28 x 20 min, OIII 27 x 20 min, SII 29 x 20 min
Total exposure: 28 hours
Image composition: False Colour Hubble Palette (SII, Ha, OIII mapped to RGB)
Scale: 1.49 arcsec/pixel
Image acquired: 23rd November 2014 – 6th February 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL; PixInsight; Photoshop CC 2014

TS Photoline 60mm FPL-53 doublet for wide field imaging

I am now experimenting with a short focal length 60mm refractor for wide field imaging having given up on camera lenses. This is the Telescope Service Photoline 60mm compact apochromatic refractor in combination with the matching Photoline 0.79x reducer. The objective is a 60mm apochromatic ED doublet lens with a FPL-53 element by Ohara Japan. With a native focal length of 330mm the scope has a focal ratio of F/5.5. Using the Photoline 2 inch 0.79x 4-element reducer / corrector the focal length is reduced to 260mm and the scope is transformed into a F/4.2 astrograph.

A first light image from the scope of the relatively faint emission nebula IC1396 is shown below. This is a total integration of 2 hours (6 x 20 min sub-exposures) which indicates the potential of this scope for capturing extended nebula regions at great depth with speed.

Further details of the TS Photoline 60mm refractor can be found on the Telescope Service website. The specification of this scope is identical to the Stellavue SV60EDS and it provides an affordable alternative to the Takahashi FS-60CB.