IC 1396
| Emission nebula | |
|---|---|
 | |
| Observation data | |
| Distance | 2,400 ly |
| Constellation | Cepheus |
IC 1396 is a large emission nebulae, a region of ionized gas, located in the constellation Cepheus about 2,400 light years away from Earth.[1]
IC 1396 is illuminated and ionized by a very bright, massive multiple star HD 206267 at its center, except for dense globules that can protect themselves from the star's harsh ultraviolet rays. This hierarchical triple star system has two members that form a spectroscopic binary that orbit each other with a period of 3.7 days, while a third member lies further away—it is unclear whether this third member is gravitationally bound to the pair. The system is emitting a stellar wind that reaches an exceptional velocity of 3,225 km/s, among the highest measured for stars of this type.[2]
Jutting from the rim of the nebula is IC 1396A, commonly called the Elephant's Trunk Nebula, a dark, dense globule with a bright, sinuous rim being illuminated by HD 206267.
See also
[edit]References
[edit]- ^ Matthews, HI (1979). "High resolution radio observations of bright rims in IC 1396". Astronomy and Astrophysics. 75: 345–50. Bibcode:1979A&A....75..345M.
- ^ Wojdowski, P. S.; et al. (December 2002), "The Hot Star Triplet HD 206267A", High Resolution X-ray Spectroscopy with XMM-Newton and Chandra, Proceedings of the International Workshop Held at the Mullard Space Science Laboratory of University College London, Holmbury St Mary, Dorking, Surrey, UK, October 24–25, 2002: 49, Bibcode:2002hrxs.confE..49W
Sources
[edit]- Osterbrock, D. E. (1957). "Comet-Tail Structures in Emission Nebulae". The Astrophysical Journal. 125. IOP: 622–635. Bibcode:1957ApJ...125..622O. doi:10.1086/146336.
- Schmidt, Edward G. (1974). "The Structure of Ionization Fronts in H II Regions". Monthly Notices of the Royal Astronomical Society. 169 (1): 97–116. doi:10.1093/mnras/169.1.97. ISSN 0035-8711.
External links
[edit]- IC 1396 in Mapped Color 17 August 2004. Russell Croman Astrophotography. Retrieved 2010-10-13
