Milky Way from Cygnus to Perseus: Many prominent HII regions
A 45°×60° view of the Milky Way in the constellations Cygnus, Cepheus, Cassiopeia, Camelopardalis, and Perseus is presented. This region is full of prominent emission nebulae. For many of them, the ionization sources are known, allowing their distances to be determined.Click on the image to load a high resolution (363 MP) version using a JavaScript viewer.
Pseudo-color composite where the color depends on Hα intensity (without continuum), as shown in the legend with units Rayleighs.
The Brightest stars are added in white to visualize the regions where Hα intensity is uncertain due to contamination by starlight.
(Unless pixels are saturated, adding white stars does not destruct the intensity information contained in the color, because the color map was chosen so that one color component (red, green, or blue) is always zero.
Thus, the color can be reconstructed by subtracting the value of the smallest component from the other two components.)
The numerous nebulae in that image can be annotated using the JavaScript viewer (click on the image) by pressing the ‘3’ key or via menu (‘F2’ key), where catalogs can also be selected.
The following section provides more details about some interesting structures.
Remarks
This section provides additional information about the objects visible in the images above. This section provides additional information about the objects visible in the images above. Click on the following links to load a JavaScript presentations:- SH2-190 and W4 superbubble/chimney: SH2-190 (aka Heart Nebula) with a faint loop extending from it. This structure is the W4 superbubble, sometimes referred to as the W4 chimney because as it is believed that hot gas is transferred from the galactic disc to the halo through such structures (see Lagrois et al., 2009). The brightest region (SH2-190) is ionized by the cluster IC 1805, located in a distance of about 2000 pc (Gaia DR3). At this distance, the W4 structure has similar dimensions to the much closer Orion-Eridanus superbubble.
- SH2-171 region: Ionized by the CEP OB4 association, located at a distance of about 1100 pc.
Image data
This image was calculated using data from the Northern Sky Narrowband Survey, DR0.1. Click the link for detailed information or visit the instruments page for information about the equipment. Here is some additional image-specific information:
| Center position: | RA: 1:02h, DEC: 66° |
|---|---|
| FOV: | 60°×45° (RA×DEC, through center) |
| Orientation: | JavaScript viewer: North is up Above: North is right |
| Scale: | 10 arcsec/pixel (in center at full resolution) |
| Projection type: | Stereographic |
References
- Dominic Lagrois and Gilles Joncas. On the Dynamical Evolution of H II Regions: An Investigation of the Ionized Component of W4, A Galactic Chimney Candidate. II. Kinematics and Dynamics in the Latitude Range 3°; < b <= 7°. ApJ, 693(1):186–206, March 2009. [ DOI ]
This work made use of the SIMBAD database, maintained by CDS, Strasbourg, France, and the Gaia public archive.
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