IC 410 is a faint emission nebula in the nebula-rich constellation of Auriga. The embedded cluster NGC 1893 ionizes the gas in the nebula and sculpts the tadpoles.
It is unlikely that you will be able to visually observe this faint nebula from the city.
Description
Cluster NGC 1893
The bright open cluster NGC 1893 is about 12 arcminutes across and contains approximately 20-30 stars in a crescent shape. NGC 1893 is very young – approximately 4 million years old – and has a magnitude of 7.5. These intensely hot young stars ionize the nebula’s gas, causing it to glow.
The Tadpoles of NGC 410
The nebula IC 410 has very low surface brightness and has a diameter of 40 arcminutes. It is in this pond of gas and dust that the the cosmic tadpoles swim in!
The tadpoles themselves are composed of denser cooler gas and dust. Each is around 10 light-years long and they are probably sites of ongoing star formation. The cluster stars sculpt the tadpoles with their winds and radiation – outlining their heads with bright ridges of ionized gas while causing their tails to trail away from the cluster’s central region.
Acquisition and Image Processing
It was particularly difficult to image the IC 410 tadpoles due to the low surface brightness of the nebula requiring longer total exposure. Furthermore, rainy weather, gusty winds, and mirror flop issues (when my telescope was pointed at high angles) all limited the amount of imaging time per night.
In the end, I acquired the image over the course of 2 months and clocked a total exposure time of more than 12 hours!
The Pixinsight imaging processing workflow I used was as follows (I did not do the usual Dynamic Background Extraction since the image was almost all nebula):
Narrowband Data:
- Noise reduction (TGV)
- Convolution to smooth the image a tad bit
- Masked stretch
- Combination into LRGB image
Luminance Data (synthetic combination of narrowband data):
- Deconvolution
- Sharpen (Multiscale Median Transform)
- Noise reduction (TGV)
- Masked stretch
- Combination into LRGB image
I tweaked the LRGB image for color (reduce magenta halos around stars, hue shift the greens slightly to blue and red, and subtracted some of the green) and stretched it to produce the final image.