PiFinder™ Catalogs =================== The PiFinder ships with several astronomical catalogs you can search and filter. Each carries a short catalog code shown on the UI. Choose which catalogs are active in the :ref:`Filters` menu. A few catalogs — the Washington Double Star catalog especially — hold far too many entries to scroll. For those, use **Name Search** to jump to an object by its designation, or sort by **Nearest** to surface the objects closest to where your scope is pointed. Abl ---- The Abell Catalog of Planetary Nebulae (George O. Abell, 1966): 79 confirmed planetary nebulae. Arp ---- Atlas of Peculiar Galaxies (Arp 1966). Galaxies with unusual morphology. See `Wikipedia - Atlas of Peculiar Galaxies `_ B ---- Barnard's Catalogue of 349 Dark Objects C ---------- Caldwell catalog Col ---------- 471 open clusters compiled by Swedish astronomer Per Collinder. EGC ---- Catalog of Extra-Galactic Globular Clusters: globulars associated with nearby galaxies, mostly in Andromeda, visible through modest amateur telescopes. H ---------- A subset of William Herschel's original Catalogue of Nebulae and Clusters of Stars, selected in response to a letter in Sky and Telescope. Harris ------- Globular Clusters in the Milky Way (Harris, 1997). Compiled by William E. Harris, used by permission. IC ---------- IC catalog Lyn ---- Open Cluster Data, 5th Edition (Lyngå 1987) — 1,151 open clusters. M ---------- Messier catalog NGC ---------- NGC 2000.0, The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J.L.E. Dreyer (edited by R.W. Sinnott). RDS ---- The RASC Double Stars Observing Program: 110 double-star targets visible from the northern hemisphere across many constellations. SaA ---------- Saguaro Astronomy Club Asterisms Database Version 3.2 SaM ---- Saguaro Astronomy Club Double Star Database Version 4.0: 2,162 double stars. SaR ---- SAC Red Stars Database Version 2.0 Sh2 ---- 313 H II regions (emission nebulae), comprehensive north of declination −27°. Str ---- Named bright stars. Especially useful for aligning GoTo scopes. Ta2 ---------- The TAAS 200 deep-sky observing list for the intermediate observer: the best 200 non-Messier objects easily visible from central New Mexico (north of declination −48°). TLK ---- TLK's hand-picked list of interesting variable stars visible from the northern hemisphere. WDS ---- The PiFinder includes over 130,000 double and multiple star pairs from the Washington Double Star Catalog. The full list is far too long to scroll, so find a pair with **Name Search** (type its WDS designation) or sort by **Nearest** to bring up the doubles closest to where your scope is pointing. For more on WDS, see `https://www.astro.gsu.edu/wds/ `_