The Lagoon nebula (also Messier 8, NGC 6523, Sharpless 25, RCW 146 and Gum 72) is an emission nebula and as an H II region in Sagittarius (H II is ionized hydrogen, and it is of importance to imagers as it emits in the H-alpha band). The Lagoon is about 4,100 light years away from earth and contains a number of Bok globules. It is relatively large, with an apparent dimension of 90×40 arcminutes, that is the angular size of 2 moons side by side. It is also relatively bright, with a 4.6 apparent magnitude.
The data proposed here consists of a 2 panels mosaic, imaged with 7 filters (Luminance, Red, Green, Blue, Hydrogen Alpha, Oxygen III and Sulfur II). All channels (including SII) show a pretty strong signal to noise ratio. Imaging lasted a month, from July 17 to August 16, 2023. Both color and narrow band images were recorded at the darkest possible hours, either during new moon, or when the moon was below the horizon.
The narrow band data has 202 frame of 5 minutes, amounting to about 17 hours, while the color and luminance data have 342 frames of 2mn, amounting to 11.4 hours of exposure. The total exposure distributed for this target exceeds 28 hours to reach the highest quality possible with the equipment used.
My interpretation of the data, in color and narrow band is below. I like to minimize the starfield, push the dynamic range and be a bit aggressive on noise suppression for a smoother look. I link to other interpretations of the same dataset for comparison below.
Here is the RGB dataset for the first tile T1 of the mosaic:
Here is the RGB dataset for the second tile T2 of the mosaic:
Here is the SHO dataset for the first tile T1 of the mosaic:
Here is the SHO dataset for the second tile T2 of the mosaic:
On the first night, I mistakenly recorded the RGB frames at 5mn exposure like I do for SHO, instead of the 2mn intended for RGB for a target that bright. So this first night resulted in slightly deeper data, but also more saturated stars. I hesitated if this was worth even distributing, but somebody may find a use for those frames. So here are the 5mn dataset for both tiles, T1 and T2, for the first night on target:
And the calibration files:
Here is a creative processing of the dataset by user Taras M, and a close to the data rendering by George H. Here is a high dynamic range version by user Bernard D.
Here is a link to a video tutorial by astronomer YS Lee on how to process the M8 dataset distributed here with Pixinsight. The same astronomer earned a “Top Pick Nomination” on Astrobin for his work with M8. Congratulations on the award and a very nice processing! Thanks also for sharing processing expertise with the community.