It is a type of emission nebula rich in hydrogen and oxygen.

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Discovered by William Hershel in 1792.

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It is approximately 5,000 light years away from Earth.

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It is best to observe it from the beginning of summer until October, when it is highest in the sky.

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In very good conditions, you can see a light haze using an 8 cm diameter telescope and an oxygen filter, to see the distinct shape of the crescent nebula you need to use a 20 cm diameter telescope mirror with an oxygen filter.

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The size of this nebula is estimated at 26 x 17 light years.

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Interesting fact: The nebula was created by the interaction of the outer layers of the Wolf-Rayet star WR 136 and a nearby nebula about 250,000 years ago. According to scientists, this star may explode as a supernova in the near future.

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