This image is a 2 panel RASA mosaic centered upon IC 1396, an open star cluster located 3000 light years away in the constellation of Cepheus at a declination of +57 degrees.
The most spectacular object here is of course IC 1396a, the “Elephant Trunk” bright rimmed dark globule. The trunk is over 20 light-years long. At the center of the end of the trunk are two young T Tauri stars. These stars have carved out a cavity in the globule from their powerful stellar winds. Just below and right of these stars is vdB 142, a small blue reflection nebula.
Although the Elephant Trunk is the highlight here, I also enjoyed these other objects in the image (going from the top of the image to bottom):
- The wonderfully complex planetary nebula PK100+04.1, seen at 21:40:59 RA & 58:58:41 DEC at the top center of the image. A closeup image of it taken with my C11 is seen here.
- The red supergiant magnitude 4 star Erakis (Mu Cephei), seen at upper left and also known as Herschel’s Garnet Star. This is one of the largest known stars, with a radius 1000 times our sun, and has several delicate dark nebula just below it.
- The many dark larger nebulae (many of them Barnard nebula) silhouetted against blue emission signal throughout the center of the nebula.
- The tight grouping of 3 bright blue stars at the center of the image. This is the star complex HD 206267, which is the center of the open star cluster IC 1396, also known as Trumpler 37. It is also the main source of excitation for the surrounding nebula.
- At the center of the image and ¾ of the way down, the small orange-rimmed cometary globule GN 21.38.9 seen at 21:40:30 RA & 56:35:29 DEC.
- At the bottom right of the image at 21:32:12 RA & 55:52:51 DEC, the small planetary nebula Abell 77, also known as Sh2-128. A closeup image of it taken with my C11 is seen here.
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