The list of HOU keywords in VOcabulary format (Version 2007-08-31) Star star Double or multiple star star.binary;star.multiple Star in double system star;isElementOf;star.binary Star in Cluster star;isElementOf;star.cluster Star in Nebula star;isElementOf;diffuse.nebula Unknown stat.unknown Active Galaxy Nucleus galaxy.AGN Eclipsing binary of Algol type star.binary.eclipsing;star.binary.Algol-class Association of Stars star.cluster.association Asteroid planetary.asteroid BL Lac - type object galaxy.AGN.BLLac-class Bright Nebula diffuse.nebula.bright Compact Group of Galaxies galaxy.group.compact Cataclysmic Variable Star star.binary.CV Classical Cepheid variable Star star.variable.deltaCep-class Cluster of Stars star.cluster Cluster of Galaxies galaxy.cluster Cluster with Nebulosity star.cluster;diffuse.nebula.bright Come planetary.comet Double Star star.binary Dark Nebula diffuse.nebula.dark Diffuse Nebula diffuse.nebula Eclipsing binary star.binary;time.variation.eclipse Emission-line Star star;physics.line Emission Nebula diffuse.nebula.bright Galaxy galaxy Elliptical Galaxy galaxy.elliptical Irregular Galaxy galaxy.irregular Lenticular Galaxy galaxy.lenticular Galactic Nebula diffuse.nebula;isElementOf;named.MilkyWay Spiral Galaxy galaxy.spiral Galaxy in Pair of Galaxies galaxy;isElementOf;galaxy.group Globular Cluster star.cluster.globular Group of Galaxies galaxy.group Galaxy in Group of Galaxies galaxy;isElementOf;galaxy.group HII (ionized) region diffuse.nebula.HII Moon Terminator named.Moon;morphology.edge Multiple Star star.multiple Moon named.Moon Moon Crater named.Moon;process.crater Not Classified source;stat.unknown Nebula of unknown nature diffuse.nebula;stat.unknown Nova star.binary.CV.nova No Entry stat.unknown Occultation time.variation.occultation Open (galactic) Cluster star.cluster.open High proper-motion Star star;source.properMotion Planetary Nebula diffuse.nebula.planetary Peculiar Star star.peculiar Planet planetary.planet Quasar galaxy.AGN.quasar Reflection Nebula diffuse.nebula.reflection Spectroscopic binary star.binary.spectroscopic SuperNova star.supernova SuperNova Remnant misc.SNR Sky Patch sky.region Seyfert 2 Galaxy galaxy.Seyfert-class.2 Seyfert Galaxy galaxy.Seyfert-class Unknown Object source;stat.unknown Variable Star star.variable Eclipsing binary of W UMa type star.binary.WUMa-class