The System of the Stars

61 Cygni 70 Ophiuchi absorption Algol appear Arcturus Astr astronomy Astroph binary blue bodies bright Cape Cassiopeia Catalogue centre century cluster colour companion components Cygni dark detected displacements distance double stars eclipses effect faint galactic gaseous globular clusters Harvard Annals Heliometer helium hence Huggins hydrogen Ibid interval Journ Kapteyn less Lick light Light-Curve lines luminous lustre Lyræ magnitude star mass Max Wolf means measures Milky Monthly Notices movements nearly nebula Nova objects Observatory observed Ophiuchus orbit Orion Orion nebula pair parallax period Phil photographic Pickering planetary plates Pleiades Professor proper motions radial velocity radiation rays red stars refractor remarkable remote revolution satellite shining sidereal Sir John Herschel Sir William Sirian Sirius small stars solar southern space spectra spectroscopic Spectroscopic binary spectrum stellar Struve sun's telescope tion Trans variable variable stars velocity visible visual William Huggins