Straddling the boundary of Taurus and Auriga, is the giant supernova remnant (SNR) Simeis-147 AKA SH2-240 or the Spaghetti Nebula.  It is believed that the stellar explosion that created Simeis-147 occurred some 40,000 years ago, leaving behind a rapidly spinning neutron star or pulsar at the core of the now complex, expanding SNR; the nebulous area has an almost spherical shell consisting of numerous filamentary structures.  With an apparent diameter of 3^o the SNR spans some 160 light-years, making it a very large astrophotography target.  

I’ve long admired the spectacular SNR Simeis-147 AKA Spaghetti Nebula, which I first imaged with my standard William Optics GT81 scope in January 2022.  The outcome (see image below) was pleasing but with the limited FOV it had to be just a nibble of this large object – something of an appetiser you might say.  Therefore, ever since putting my Samyang rig together last summer I’ve had only one object in mind with this excellent widefield set-up, which had to be the full menu version of Simeis-147!

Apart from its size, Simeis-147 is very faint, making long exposure time essential, which is always difficult in the UK.  However, a rare spell of cold, clear nights this January provided sufficient opportunity over five nights to obtain just over 20-hours integration and a complete image of this truly magnificent SNR.

Notwithstanding the favourable conditions and long-time achieved – a record for me at this location – the faint nature of this object made image processing difficult too.  After experimenting, I eventually adopted a tone mapping technique: pre-processing each individual wavelength stack before removing the stars, stretching and processing each of the starless Ha and OIII images before combining using Pixel Math in the ratio: R – (Ha*1.70) + G – (OIII*0.80)+(Ha*0.20) + B- (OIII*0.80)+(Ha*0.20). 

With further processing of the HOO starless combination I was able to obtain the desired result of marvellous SNR detail, together with pleasing Ha (red) and especially OIII (blue/green) colours, that altogether with the addition of the stars and some final tweaking produced a striking image with good depth.  Moreover, I feel the widefield setting achieved using the Samyang 135 lens produces a striking setting for this fascinating object.