This object is a supernova remnant (SNR) located 800 light years away in the southern constellation of Vela at a declination of -46 degrees. This field of view is a small part of the amazing Vela SNR. The brightest portion of this SNR in the left half of the image is 0.5 degrees long, which corresponds to an actual length of 6 light years.
Based on expansion calculations and distance measurements, the supernova is believed to have occurred about 10,000 years ago, so bright that it was visible by naked eye during the daytime. It must have been quite a sight and a wonder to behold for the inhabitants of earth at that time.
This beautiful object is a tough capture for us in the northern hemisphere. From my location, the object transits a maximum of 13 degrees above the horizon.
In
my original image, taken with a refractor using 3x the integration time, the straight nature of the bright portion of the SNR on the left side of this image really puzzled me. Now, seeing more of the SNR in a wider field of view, I see that straight section replicated many times on the right side of the image, looking like a more natural outcome of the outward movement of the SNR expansion.
In most of the other SNR I have imaged, the oxygen and hydrogen signals are well balanced. Here, the oxygen signal is dominant.
NGC 2736 is sometimes nicknamed Herschel’s Ray after its discoverer, John Herschel, who described it as “an extraordinary long narrow ray of excessively feeble light”. It is also nicknamed the Pencil Nebula by someone with a similar lack of imagination to me. As I have said many times, I am not a big fan of nicknames.
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