This website uses the excellent DSO object database created by the Saguaro Astonomy Club. They have various types of categorisation for their DSOs, and to help explain them, here is the list with an example object that you might be able to see.
| Type | Explanation | Example |
|---|---|---|
| Asterism | A pattern of stars seen in Earth's sky which is not an official constellation. | Kemble's Cascade |
| Bright Nebula | Large clouds of gas and other particles that shine due to reflected star light or by light emitted due to charged particles interacting with interstellar radiation. | Eta Carinae |
| Cluster with Nebulosity | Clusters of stars with associate gasses and particles which reflect the stars' light/radiation. | Pleiades |
| Globular Cluster | A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. | 47 Tucanae |
| Galaxy | A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, and an interstellar medium of gas and dust. | M31 Andromeda |
| Galaxy Cluster | Groups of galaxies which are the largest known gravitationally bound objects to date. | Coma I |
| Globular Cluster in a Galaxy | A spherical collection of stars that orbit a galactic core in a galaxy outside of the Milky Way. | NGC 1049 |
| Cluster with Nebulosity in the Large Magellanic Cloud | Clusters of stars with associate gasses and particles which reflect the stars' light/radiation, located within the LMC. | Tarantula |
| Open Cluster | A group of up to a few thousand stars formed from the same giant molecular cloud which are still loosely gravitaionally bound to eachother. | Hyades |
| Planetary Nebula | A nebula consisting of an expanding glowing shell of ionized gas and plasma ejected by certain types of stars late in their life. Named 'planetary' because of their similarity in appearance to giant planets when viewed through small telescopes, but is otherwise unrelated to planets. | Helix |
| Quasar | A quasi-stellar radio source (quasar) is a very energetic and distant galaxy with an active galactic nucleus. Quasars were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than extended sources similar to galaxies. | 3C 273 |
| Cluster with Nebulosity in the Small Magellanic Cloud | Clusters of stars with associate gasses and particles which reflect the stars' light/radiation, located within the SMC. | NGC 346 |
| Globular Cluster in the Small Magellanic Cloud | A spherical collection of stars that orbit the galactic core of the SMC. | NGC 419 |
| Open Cluster in the Small Magellanic Cloud | A group of up to a few thousand stars formed from the same giant molecular cloud which are still loosely gravitaionally bound to eachother, in the SMC. | NGC 220 |
| Supernova Remnant | A supernova remnant is the structure resulting from the gigantic explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. | Western Veil |
| Double stars (2 star) | a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary system of stars in mutual orbit, gravitationally bound to each other, or because it is an optical double, a chance alignment of two stars in the sky that lie at different distances. | Winnecke 4 |