Emission Nebula in constellation “Cepheus”
Project #7
IC1396 – Object Description
The Elephant’s Trunk Nebula is a concentration of interstellar gas and dust within the much larger ionized gas region IC 1396 located in the constellation Cepheus about 2.400 light years away from Earth. The piece of the nebula shown here is the dark, dense globule IC 1396A; it is commonly called the Elephant’s Trunk nebula because of its appearance at visible light wavelengths, where there is a dark patch with a bright, sinuous rim. The bright rim is the surface of the dense cloud that is being illuminated and ionized by a very bright, massive star (HD 206267) that is just to the east of IC 1396A. The entire IC 1396 region is ionized by the massive star, except for dense globules that can protect themselves from the star’s harsh ultraviolet rays.
The Elephant’s Trunk Nebula is now thought to be a site of star formation, containing several very young (less than 100.000 yrs) stars that were discovered in infrared images in 2003. Two older (but still young, a couple of million years, by the standards of stars, which live for billions of years) stars are present in a small, circular cavity in the head of the globule. Winds from these young stars may have emptied the cavity.
The combined action of the light from the massive star ionizing and compressing the rim of the cloud, and the wind from the young stars shifting gas from the center outward lead to very high compression in the Elephant’s Trunk Nebula. This pressure has triggered the current generation of protostars. (Source: Wikipedia)
IC1396 – Project Publications
Image Publications
Please find all project-related image publications for this revision below.
Image and Signal Comparisons
Standard vs. starless version;
OIIIIn astronomy, doubly ionized oxygen is the ion O2+ (O III in spectroscopic notation). Its emission forbidden lines in the visible spectrum fall primarily at the wavelength 500.7 nm, and secondarily at 495.9 nm. Concentrated levels of O III are found in diffuse and planetary nebulae. Consequently, narrow band-pass filters that isolate the 500.7 nm and 495.9 nm wavelengths of light, that correspond to green-turquoise-cyan spectral colors, are useful in observing these objects, causing them to appear at higher contrast against the filtered and consequently blacker background of space (and possibly light-polluted terrestrial atmosphere) where the frequencies of [O III] are much less pronounced. (Source: Wikipedia) More vs. HalphaH-alpha (Hα) is a deep-red visible spectral line of the hydrogen atom with a wavelength of 656.28 nm in air and 656.46 nm in vacuum. It is the first spectral line in the Balmer series and is emitted when an electron falls from a hydrogen atom's third- to second-lowest energy level. H-alpha has applications in astronomy where its emission can be observed from emission nebulae and from features in the Sun's atmosphere, including solar prominences and the chromosphere. (Source: Wikipedia) More signal;
IC1396 – Project Details
Please find all project-related details for this revision below.
I would like to thank my friend Daniel Nimmervoll for the great workshop where the final revision above was created.
| Astrobin Link | IC1396 / Elephant’s Trunk Nebula with OSC+Dual Narrowband (HO) |
| Further Publications | spektrum.de – IC1396 / Elephant’s Trunk Nebula |
| Astronomical Object | IC1396 |
| Distance to Earth | 2.400 light years |
| Size / Diameter | 170′ x 140′ (arcmins) |
| Date(s) of Photography | March 2023 April 2023 |
| Exposure Details | Dual NB: 97 x 300″ (8h 5min) Clearglass: 100 x 180″ (5h 0min) Total: 13h 5min |
| Calibration | FlatsA "flat frame" is shot against a bright surface and contains vignetting and all the "bad" things (e.g. dust particles) that block/disturb your light train. The combination/stack of multiple flat frames is called a "Master Flat". More: 50 Dark-Flats: 50 Master-Dark |
| Equipment | Mount: Skywatcher EQ6-R PRO (the old w/o USB-interface) Telescope: Skywatcher 200PDS Newton (200mm/1000mm, f/5) Camera: Touptek DeepSky Pro 2600c (Gain: 100, Offset: 100) Clearglass Filter: Baader Clearglass 2″ Dual Narrowband Filter: Optolong L-eXtreme 2″ Corrector: Pál Gyulai GPU Komakorrektor Guiding(Auto-)Guiding is essential in astrophotography, as an un-guided mount/telescope will produce blurry images as the stars / the deepsky object will drift away. This is heavily dependent on the exposure time, so for long exposures you want to make sure to have a perfectly set up auto-guiding. More: ZWO ASI120MM + 50mm Helical GuideScope |
| Software | Observatory Automation: Sequence Generator Pro Guiding(Auto-)Guiding is essential in astrophotography, as an un-guided mount/telescope will produce blurry images as the stars / the deepsky object will drift away. This is heavily dependent on the exposure time, so for long exposures you want to make sure to have a perfectly set up auto-guiding. More: PHD Post-Processing: Astro Pixel Processor + PixInsight + Photoshop |
