Milky Way from Monoceros to Gemini

On this page a 21°×40° wide-field view of the Milky Way in the constellations Monoceros, Orion and Gemini is presented. All pictures below are downscaled versions. Full resolution images with more than 100 megapixels can be loaded with a Javascript viewer by clicking on the images in the first section. Selected details are shown in a second section Image and instrument data can be found at the end of this page.

There are short descriptions below each image.

Full views

Click on the images to load a full resolution version with up to more than 100 megapixels using a JavaScript viewer. If browser cannot handle this or in case of low bandwidth connections you can try the half resolution version. The links can be found below the images.

Some browsers (namely Gecko based ones like Firefox) cannot downscale properly with Javascript, they just downsample. This results in noisy images and randomly appearing and disappearing stars while zooming. If such artifacts appear you can try the direct download version and use the browsers built-in viewer. Download links can be found below the images.

Direct download is also recommended for mobile devices (and devices with touchscreen) because browsers for these devises usually have a integrated viewer which is faster than the Javascript viewer and can handle larger data.

Milky Way from Monoceros to Gemini in H-alpha (red), blue continuum (green) and red continuum (blue)
Full resolution (52 MB): Javascript Viewer Direct download
Half resolution (14 MB): Javascript Viewer Direct download
 
This visualization is a false color image where H-alpha (including red continuum) is mapped to red, blue continuum is mapped to green and red continuum (without H-alpha) is mapped to blue. Reflection nebulae appear green to blue. Emission nebulae appear mostly red to orange, because blue continuum (mapped to green) also receives some emission lines like [OIII].
 
Stars in the continuum channels are partially subtracted. Further image processing steps are dynamic range compression using a nonlinear hi-pass filter and tonal curve correction.

Milky Way from Monoceros to Gemini in H-alpha (false color)
Legend for false color image of Milky Way from Monoceros to Gemini in H-alpha
 
Full resolution (52 MB): Javascript Viewer Direct download
Half resolution (12 MB): Javascript Viewer Direct download
 
This visualization is a false color image which only uses the H-alpha data (including some red continuum). It shows much more details of the emission nebulae then the image above.
 
After partial star subtraction the dynamic range was compressed using a non-linear hi-pass filter. That leads to a compression ratio r which is used to calculate the color as depicted in the legend. (The legend shows the compression c:=1-r). The luminance is determined by the tonal curve corrected result of the dynamic range compression.

Milky Way from Monoceros to Gemini region in RGB
Half resolution 13 MB): Javascript Viewer Direct download
 
This image comes close to a true color view. Red component shows red continuum including some (but reduced) H-alpha, green continuum is mapped to green and blue continuum is mapped to blue.
 
Unlike to the other images the stars are not subtracted. This makes the dark nebulae visible which cover the light from the stars behind.
 
The only image processing step after color composition was a tonal curve correction (no dynamic range compression).
 
Due to the lack of other details than stars and thus the bad compressibility the image is only presented at half resolution.

All image processing steps are deterministic, i.e. there is no manual retouching or any kind of non-reproducible adjustment.

Selected details

Here are a few details that also can be seen using the Javascript viewers (if browser works correctly).
NGC 2264, Rosette Nebula and IC 447
Nebula complex containing NGC 2264 (SH2-273, with the Cone Nebulae) and the Rosette Nebula (SH2-275). The turquoise reflection nebula is IC 447.
NGC 2264, Rosette Nebula and IC 447 in false colors made from H-Alpha
Same view as above, but here in H-alpha false colors.
SH2-249 (IC 444), Jellyfish Nebulae (SH2-248, IC 443), Monkey Head Nebula (NGC 2174, SH2-252)
The three largest nebulae from top left to bottom right are: SH2-249 (IC 444), next to it: Jellyfish Nebula (SH2-248, IC 443, a supernova remnant) and the Monkey Head Nebula (NGC 2174, SH2-252)
Orion region: Detail of Barnards loop
Nebula complex containing the Seagull Nebula (the center part of the large structure across the whole image) and Thor's Helmet (NGC 2359, SH2-298, the small structure in the lower left quarter). The latter nebula is ionized by the Wolf-Rayet star WR7. It is assumed that the most ionized material is interstellar gas, see [1].

Image data

Images where captured with a camera array which is described on the instruments page.

Image data are:

Projection type: Stereographic
Center position: RA: 6h46, DEC: 5°
Orientation: North is up (exactly)
Scale: 10 arcsec/pixel (in center at maximum resolution)
FOV: 21°×40° (through center)
Exposure times: H-alpha: 7.8d, continuum channels: 4.5d (sum of exposure times of all frames used to calculate the image)

References

1. Cappa, C. E.; Goss, W. M.; Niemela, V. S.; Ostrov, P. G. (1999). A Study of Neutral and Ionized Gas of the Wolf-Rayet Ring Nebula NGC 2359.

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