Sharpless 236 is a large H II region surrounding the open cluster NGC 1893. The nebula is characterized by its distinctive tadpole-like structures, formed by the interaction between the hot, young stars of NGC 1893 and the surrounding gas and dust. These features make Sh2-236 a popular target for astrophotographers, who often capture its intricate details using narrowband filters. The nebula’s complex structure and vibrant colors, particularly when imaged using hydrogen-alpha, sulfur-II, and oxygen-III filters, create stunning visual representations of this cosmic nursery.
Names and Catalog numbers
- Tadpole Nebula
- Sharpless 236 (Sh2-236)
- IC 410
- LBN 807
Position and the cosmic neighborhood
Sharpless 236 is situated within a larger nebulous region in the Milky Way, which includes other notable objects such as the Flaming Star Nebula (Sh2-229 or IC 405). The nebula is part of a complex that spans several degrees in the night sky, making it an expansive target for wide-field astrophotography. Its location in Auriga places it in a rich star field, surrounded by numerous other deep-sky objects that are popular among amateur astronomers.
Nice to Know
- The nebula’s distinctive tadpole-like structures are sculpted by the stellar winds and radiation from the young, hot stars in NGC 1893.
- Astrophotographers often use narrowband filters (SII, H-alpha, and OIII) to capture the nebula’s intricate details and create stunning false-color images.
- Sharpless 236 is associated with the radio source W8, indicating significant radio emission from the region.
- The nebula is part of the Sharpless catalog, which contains 313 H II regions and was compiled by astronomer Stewart Sharpless in 1959.
Brightness, distance and size
Sharpless 236 is a relatively faint object, making it challenging to observe visually but an excellent target for long-exposure astrophotography. The nebula is estimated to be between 2185 light-years away from Earth, placing it well within our Milky Way galaxy. While precise measurements of its physical size are not readily available, the nebula spans a considerable portion of the sky, with some estimates suggesting it covers an area of several arcminutes. This large apparent size, combined with its distance, indicates that Sharpless 236 is a truly massive structure, likely spanning dozens of light-years across.
