IC 1396, Elephant Trunk Nebula


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]

IC 1396
IC 1396: Elephant Trunk Nebula; Celestron RASA 11" f/2.22; ZWO ASI6200 Pro; Tentlingen; © 2020 Peter Kocher
IC 1396
IC 1396: Elephant Trunk Nebula; Astrooptik Keller Cassegrain 400mm f/3, SBIG STL-11000M; Filter L + R + G + B + SII + Hα + OIII, total 12h; Observatory Oberes Schlierental, Obwalden; © 6.-11. 10. 2010 Eduard von Bergen
IC 1396
IC 1396: Elephant Trunk with globule in IC 1396; 500 mm Cassegrain f=3625 mm f/7.2; SBIG STL11K; 120+3*40 min; Bernese Highlands; © 2011 Radek Chromik

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 New General Catalogue and Index Catalogue», «Historically Corrected New General Catalogue», Dr. Wolfgang Steinicke, 2021 [277]
NameRADecTypeBmagVmagDimDreyer DescriptionIdentification
IC 1396 21 38 54.0+57 29 20EN170.00 × 140.0Neb part of M. WayLBN 451/452, SG 1.19
IC 1396 A21 35 30.0+57 23 00EN14.00 × 2.0Neb part of M. WayLBN 452
IC 1396 B21 34 30.0+57 28 00EN12.00 × 4.0Neb part of M. WayLBN 451

Finder Chart

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

Chart IC 1396
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]


149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
196Celestial Atlas by Curtney Seligman; cseligman.com/text/atlas.htm (2020-12-28)
255«A study of reflection nebulae» van den Bergh, S.; Astronomical Journal, Vol. 71, p. 990-998 (1966); DOI:10.1086/109995
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)
360«Near-infrared Variability of Low-mass Stars in IC 1396A and Tr 37» Huan Y. A. Meng, G. H. Rieke, Jinyoung Serena Kim, Aurora Sicilia-Aguilar, N. J. G. Cross, Taran Esplin, L. M. Rebull, and Klaus W. Hodapp; Published 2019 June 6; The Astrophysical Journal, Volume 878, Number 1; DOI:10.3847/1538-4357/ab1b14
361«IRAM and Gaia views of multi-episodic star formation in IC 1396A — The origin and dynamics of the Class 0 protostar at the edge of an HII region» Aurora Sicilia-Aguilar, Nimesh Patel, Min Fang, Veronica Roccatagliata, Konstantin Getman and Paul Goldsmith; A&A Volume 622, February 2019; DOI:10.1051/0004-6361/201833207