Monthly Archives: February 2015

NGC2264 – Cone and Fox Fur Nebula

NGC2264-v1.3sNGC 2264 describes several objects in the constellation Monoceros lying about 2,700 light-years from Earth. One is the Christmas Tree star cluster nearby the blazing bright blue star S Monocerotis at centre right. The surrounding diffuse nebula is caused by H-alpha emissions from hydrogen gas stimulated by ultraviolet radiation emitted by S Monocertis and the cluster’s other blue stars. The nebula is well known for two special star forming regions. At centre left is the Cone Nebula named for its apparent shape and sculpted by fierce stellar winds. It is a dark molecular cloud within which other new stars are forming. Numerous other sculpted swirls of nebulosity are nearby. At lower right is the Fox Fur Nebula (Sharpless 273) named after its rich textured appearance also the result of sculpting by stellar winds. In contrast, the blue reflection nebula is caused by scattered blue light reflecting off residual dust in a region where stars have already formed.

This image is a bicolour combination of Ha and OIII images to create a synthetic green image displayed as an RGB composite with Ha luminance. PixInsight DBE (Dynamic Background Extraction) was used in the absence of suitable flat frames to remove sky background noise and gradients. Photoshop CC layers and layer mask processing techniques were used for colour and spatial enhancement – Levels, Curves, Reduce Noise, Selective Color, HDR toning, Smart Sharpen, Local Contrast Enhancement and Unsharp Mask in predominant use. Additional noise reduction (TGVDenoise) and local contrast enhancement (HDRMultiscaleTransform) was carried out in PixInsight.

Right ascension: 06h 41m 08s | Declination: +09° 41′ 15″ | Distance: 2,700 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)
Exposures: Ha 8 x 20 min, OIII 11 x 20 min
Total exposure: 6.3 hours
Image composition: Cannistra Modified Bicolour Narrowband Technique
Scale: 1.49 arcsec/pixel
Image acquired: 8th, 9th & 16th February 2015

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

Widefield view of the Rosette Nebulae in Ha – NGC2237

Rosette-Ha-v3c90This is a first light image from a SMC Pentax 67 300mm lens attached to my QSI583 wide-field imaging rig. The rig is housed in my relocated observatory situated in the Polden Hills of Somerset. The image is a monochrome hydrogen alpha (Ha) image of the Rosette Nebula located in the constellation of Monoceros. Arguably one of the finest HII regions in the northern sky the region is a very active area of star formation covering approximately 130 light years and containing some 10,000 solar masses of gas and dust.

As a vintage Pentax lens the SMC Pentax 67 1:4/300 is noted for its image quality and sharpness but is not popular with photographers because of its size and weight. However this is not an issue when it is mounted on an EQ6 equatorial mount for astrophotography. This lens is the 1987 variant recently purchased in mint condition from an eBay seller in Japan. I stopped the lens down to F/5.6 to improve image sharpness and to obtain good quality and repeatable V-curves for auto focussing. The resulting image is still a little soft and further experimentation is required to optimise auto focussing of the lens.

Right ascension: 6h 32m 46.0s | Declination: +4° 55′ 25″ | Distance: 5,000 Light Years
Field of view: 206 x 155 arcmin

Camera: QSI 583
Optics: SMC Pentax 6×7 300mm Lens F/4
Guiding: Off-axis with Lodestar guider
Filters: Baader Ha (7nm)
Exposures: Ha 25 x 20 min
Total exposure: 8.3 hours
Image composition: Monochrome Ha
Scale: 2.72 arcsec/pixel
Image acquired: January – February 2015

Image capture with MaxIm DL, FocusMax, ACP; Image processed with MaxIm DL and Photoshop CS4 and HDR toning in Photoshop CC 2014.