Rho Ophiuchi (ρ Oph) is a multiple star system located at a distance of 360 ly from Earth in the constellation Ophiuchus. It is embedded in the Rho Ophiuchi cloud complex.| Star Facts
Kepler’s Supernova (SN 1604) is the remnant of a supernova first observed in October 1604. The supernova occurred in the Milky Way galaxy, less than 20,000 light-years from the Sun. It peaked at magnitude -2.25 to -2.5 and could even be seen in daytime.| www.constellation-guide.com
Barnard’s Star (Gliese 699) is a red dwarf located only 5.96 light-years away in the constellation Ophiuchus. It is the fourth nearest individual star to Earth, after the three components of the Alpha Centauri system.| Star Facts
Equatorial constellations are the 15 constellations that intersect the celestial equator. These are among the most universally recognizable constellations in the sky, visible from most places on Earth. They culminate highest when seen from locations near the equator.| www.constellation-guide.com
Learn about the 88 modern constellations, their names, history, how to identify them, why we see different constellations at different times of year, and other fun facts.| www.constellation-guide.com
Hydra is the largest constellation in the sky. Located in the southern celestial hemisphere, the constellation contains the open cluster Messier 48, the Porpoise Galaxy (NGC 2936), and the Southern Pinwheel Galaxy (M83).| www.constellation-guide.com
Cygnus, the Swan, is one of the largest northern constellations. Recognizable for the Northern Cross, it is home to the bright supergiant Deneb, the North America Nebula (NGC 7000) and the Gamma Cygni Nebula (IC 1318).| www.constellation-guide.com
Alniyat (σ Sco) is a hot blue giant star in a multiple star system located 568 light-years away in the constellation Scorpius. It is one of the two bright stars flanking the supergiant Antares.| Star Facts
Libra is one of the southern zodiac constellations. It is home to Methuselah Star (HD 140283), one of the oldest stars known, the nearby red dwarf Gliese 581, and the barred spiral galaxies NGC 5885 and NGC 5792.| www.constellation-guide.com
Hercules is one of the largest constellations in the sky. Representing the mythical Greek hero, the constellation is home to the Hercules Globular Cluster (M13), the globular cluster Messier 92, and the Hercules Cluster of galaxies.| www.constellation-guide.com
Ara is a small constellation in the southern sky. It represents the altar. It contains the open clusters NGC 6193 and the Ara Cluster, the planetary nebula known as the Stingray Nebula, and the pre-planetary Water Lily Nebula.| www.constellation-guide.com
Lupus (the Wolf) is a southern constellation located between Scorpius and Centaurus. It hosts the historic supernova remnant SN 1006, the globular clusters NGC 5824 and NGC 5986, and the Retina Nebula (IC 4406).| www.constellation-guide.com
Crux is the smallest and most distinctive constellation in the southern sky. Recognizable for the Southern Cross, formed by its brightest stars, it is home to the dark Coalsack Nebula and the Jewel Box Cluster (NGC 4755).| www.constellation-guide.com
Centaurus is a large constellation located in the southern celestial hemisphere. It is home to Alpha Centauri, the nearest star system to Earth, the bright galaxy Centaurus A, and the globular cluster Omega Centauri.| www.constellation-guide.com
Gamma Cassiopeiae (γ Cas) is a spectroscopic binary star located at a distance of 550 light years from Earth in the constellation Cassiopeia. It is the central star of Cassiopeia's W.| Star Facts
Lyra is a small constellation in the northern sky. It represents the lyre of Orpheus. The constellation is home to Vega, the second brightest northern star, and the Ring Nebula (M57), a famous planetary nebula.| www.constellation-guide.com
Vulpecula is a faint constellation in the northern sky. It represents the little fox. The constellation is home to the red giant Anser, the Dumbbell Nebula (M27), and as asterism known as the Coathanger.| www.constellation-guide.com
Sagittarius is a large constellation in the southern sky. It is one of the constellations of the zodiac. It contains the Milky Way centre and some of the best known nebulae in the sky.| www.constellation-guide.com
The list of all the named stars (stars with names that have been formally approved by the IAU), with name origins and etymologies explained.| Star Facts
Alpha Centauri (α Cen) is a triple star system located at a distance of 4.37 light years from Earth in the constellation Centaurus. It is the nearest star system to the Sun and hosts the nearest extrasolar planets to Earth.| Star Facts
Scorpius is a zodiac constellation located in the southern sky. It is home to Antares, one of the brightest stars in the sky, and to the bright open clusters Messier 6 (the Butterfly Cluster) and Messier 7 (Ptolemy's Cluster).| www.constellation-guide.com
Zeta Ophiuchi (ζ Oph) is a hot blue star located 366 light-years away in the constellation Ophiuchus. It is the closest O-type to Earth. Shining at magnitude 2.57, it is the third brightest star in Ophiuchus.| Star Facts
Antares, Alpha Scorpii (α Sco) is a red supergiant and supernova candidate located at a distance of 550 ly from Earth in the constellation Scorpius. It is the brightest star in Scorpius and one of the brightest stars in the sky.| Star Facts
Aquila, the Eagle, is a prominent northern constellation located near the celestial equator. It contains the bright Altair and the planetary nebulae NGC 6741 (the Phantom Streak Nebula) and NGC 6751 (the Glowing Eye Nebula).| www.constellation-guide.com
Charles Messier’s Catalogue of Nebulae and Star Clusters (Catalogue des Nébuleuses et des Amas d’Étoiles) is an astronomical catalogue of 110 bright deep sky objects that may be mistaken for comets. Even though it was compiled for the purpose of helping observers distinguish between permanent and transient objects in the night sky, the Messier catalogue… Read More »Messier Catalogue| Messier Objects
Messier 107 (M107) is a globular cluster located in the constellation Ophiuchus. It lies at a distance of 20,900 light years from Earth. It has the designation NGC 6171 in the New General Catalogue. M107 occupies an area of 13 arc minutes of the apparent sky, corresponding to a linear diameter of 79 light years.… Read More »Messier 107| Messier Objects
Zodiac constellations are the 12 constellations that lie along the plane of the ecliptic, which is defined by the circular path of the Sun across the sky, as seen from Earth.| www.constellation-guide.com