Star Clusters and Nebulae: Overview
Introduction
Galaxies3D explores stars clusters and nebulae in our Milky Way galaxy by looking at:
In the views of these objects, Galaxies3D anchors objects to a grid parallel to the galactic plane.
As it does in its views on the bright stars, in displaying views of star clusters and nebulae, Galaxies3D makes extensive use of this image of the Milky Way Galaxy by Robert Hurt of NASA and JPL-Caltech, presented at the 212th American Astronomical Society meeting:
The smallest circle centered on the Sun has a radius of 750 light years. The largest circles are spaced every 5000 light years from the Sun.
We use this Milky Way image to help make clear:
Messier's List of Celestal Objects
The Messier objects that lie within our Milky Way galaxy include:
In the following view of the Messier objects in our galaxy, you can see that the diffuse nebulae, planetary nebulae, supernova remnants and open star clusters all lie in a small region of the galaxy near the Sun. In contrast, the Messier globular clusters — colored red — span the breadth of the galaxy, from Messier 79 beyond the farthest spiral arm on our side of the galaxy, to Messier 54 beyond the farthest spiral arm on the other side of the galaxy:
The view below shows all the Messier objects in our Milky Way Galaxy, excluding the globular clusters. The Messier diffuse nebulae, planetary nebulae, supernova remnants, open star clusters lie:
The base grid of this image measures 16.3 kly x 16.3 kly, a small fraction of the breadth of the entire Milky Way. It is worth noting however, that the entire Large Magellanic Cloud, a magellanic spiral galaxy and the largest satellite galaxy of the Milky Way's Subgroup of Galaxies, has a diameter of 14 kly, and would nicely fit within this grid.
Famous Diffuse Nebulae, Planetary Nebulae, Supernova Remants and Open Star Clusters
Famous, — that is, named — diffuse nebulae, planetary nebulae, supernova remnants, open star clusters explored by Galaxies3D draw from both Messier's catalog and Patrick Moore's Caldwell catalog. In the views below, you can see that they also lie in our immediate region of the galaxy:
Famous Diffuse and Dark Nebulae:
Famous Open Clusters:
Famous Open Clusters Within 2900 Light Years:
Famous Planetary Nebulae and Supernova Remnants:
Young, Bright Star Forming Regions
OB Associations (associations of young, bright O and B stars), and complexes of young massive stars mark and highlight a galaxy's spiral arms. This is a view of the nearby Milky Way OB associations, by Melnik et al, Astronomy Letters 21, pp 10-26, 1995:
Here is view of the most luminous massive young star-forming complexes, cataloged by Urquhart et al, MNRAS 437, 1791-1807, 2014 (full dataset retrieved from VizieR Astronomical Server):
Globular Clusters
Globular clusters live in the halo of our galaxy, roaming far beyond and above the spiral arms and visible disk of the Milky Way. The following is a view of the known 157 globular clusters of the Milky Way. Note that the second grid lying above the base grid is the actual plane where the disc and spiral arms of the Milky Way live. The image of the Milky Way seen on the lower, base grid is actually being projected down from the upper grid to the lower, base grid. The outermost globular clusters — those farthest from the galactic center — are labeled:
Here is a view of globular clusters within 100,000 light years (100 kly) of the galactic center. Globular clusters farther than 25,000 light years of the galactic center are labeled:
Here is a view of the globular clusters with 25,000 light years of the galactic center — closer to the galactic center than the Sun:
Star Clusters and Nebulae