Elephant Trunk Nebula (IC 1396)

History

The galactic nebula IC 1396 was discovered photographically in August 1893 by the astronomer Edward Barnard. ^[196] The Canadian astronomer Sidney van den Bergh discovered a reflection nebula on the photo plates of the "Palomar Sky Survey" in the elephant trunk near the star BD + 57 ° 2309 (HD 239710), which he recorded as vdB 142 in his 1966 catalog of reflection nebulae. He noted: Type I-II (star partly inside, partly outside the nebula), moderate brightness, color blue, very strong absorption, radius 0.3 '(red) to 0.6' (blue). ^[255]

Physical Properties

IC 1396 is a large H-II region with an angular diameter of about 3°, which is home to areas of active star formation, so-called globules. The most noticeable globule is the Elephant Trunk Nebula (also often referred to as IC 1396A). This is illuminated by the trapezoid-like, variable O-type multiple star system HD 206267 located 4.5 pc away (see Fig. 3). According to Gaia DR2 measurements, this star is 945+90-73 pc from Earth. The main structure of IC 1396A measures approximately 5.4 arcminutes (about 1.4 pc) in diameter. Behind it, more dark globules and ionized, glowing gas extend over half a degree. This structure is only a small part of the large, bubble-shaped nebula around the star cluster Trumpler 37 or Collinder 439, which typically contains many variables for a young star cluster. ^{[360, 361]}

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke ^[277]
Name	RA	Dec	Type	Dim	MD	Dreyer Description	Identification, Remarks
IC 1396	21 38 54.0	+57 29 20	EN	170 × 140	0.800	Neb part of M. Way	LBN 451/452, SG 1.19
IC 1396 A	21 35 30.0	+57 23 00	EN	14 × 2		Neb part of M. Way	LBN 452
IC 1396 B	21 34 30.0	+57 28 00	EN	12 × 4		Neb part of M. Way	LBN 451

Finder Chart

The galactic nebula IC 1396 is located in the constellation Cepheus, which is best visible from May to December.

Chart Elephant Trunk Nebula (IC 1396) — Elephant Trunk Nebula (IC 1396) in constellation Cepheus. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ≈ 6.5 mag, DSS2 close-ups ≈ 20 mag. ^{[149, 160]}

Visual Observation

Description pending ...