Deep skyfield guide · 103 entries

Star clusters, nebulae, star-forming clouds, supernova remnants and nearby galaxies.

• HyadesThe Hyades is the nearest open star cluster to the Sun, a loose crowd of stars that forms the V-shaped face of Taurus, the bull, in the winter sky.
• Pleiades (M45)The Pleiades, or Seven Sisters, is a young open cluster of hot blue stars in Taurus, the most famous star cluster in the sky and known to almost every culture.
• Merope NebulaThe Merope Nebula is a reflection nebula in the Pleiades, a cloud of dust that shines blue by scattering the light of the star Merope and its neighbours.
• Orion Nebula (M42)The Orion Nebula (M42) is the nearest large stellar nursery, a glowing cloud in Orion’s sword where massive stars are being born.
• CoalsackThe Coalsack is the most prominent dark nebula in the sky, a cloud of cold dust beside the Southern Cross that blots out the bright Milky Way behind it.
• Double ClusterThe Double Cluster is a pair of young open clusters in Perseus, rich in hot blue supergiants and visible to the naked eye as a brighter knot in the Milky Way.
• Omega CentauriOmega Centauri is the largest globular cluster of the Milky Way, a dense ball of ancient stars that may be the stripped core of a swallowed galaxy.
• M13M13, the Great Globular Cluster in Hercules, is the finest globular of the northern sky, a dense sphere of old stars in the Galaxy’s halo.
• 47 Tucanae47 Tucanae is a brilliant southern globular cluster, shining beside the Small Magellanic Cloud but lying far closer, in our own Galaxy’s halo.
• M22M22 is a bright globular cluster in Sagittarius, among the closest of its kind to the Sun, seen against the rich star fields toward the centre of the Galaxy.
• Carina NebulaThe Carina Nebula is one of the largest and brightest star-forming regions in the Milky Way, a vast glowing cloud in the southern sky that holds Eta Carinae.
• Lagoon Nebula (M8)The Lagoon Nebula (M8) is a glowing cloud of star-forming gas in Sagittarius, named for the dark lane of dust that crosses it, and visible to the naked eye.
• Large Magellanic CloudThe Large Magellanic Cloud is a satellite galaxy of the Milky Way, the brightest galaxy in our sky and home to the Tarantula Nebula, its greatest stellar nursery.
• Small Magellanic CloudThe Small Magellanic Cloud is a dwarf galaxy orbiting the Milky Way with its larger twin, the place where the Cepheid key to cosmic distances was discovered.
• Sagittarius DwarfThe Sagittarius Dwarf is a small galaxy being torn apart by the Milky Way, hidden behind the Galactic Centre and trailing a stream of stars around the sky.
• Andromeda (M31)Andromeda (M31) is the nearest large spiral galaxy to the Milky Way, the other giant of the Local Group and the farthest thing most people can see unaided.
• Triangulum (M33)Triangulum (M33) is the third large galaxy of the Local Group, a loose, gas-rich spiral seen nearly face-on and one of the most distant things visible to the eye.
• Circumnuclear DiscThe Circumnuclear Disc is a clumpy ring of gas and dust circling the black hole at the centre of the Milky Way, the inner edge of the Galaxy’s gas reservoir.
• Sgr A* accretionThe Sgr A* accretion flow is the hot, thin gas spiralling around the Milky Way’s central black hole, strikingly faint for something feeding a black hole.
• Crab Nebula (M1)The Crab Nebula (M1) is the remnant of a supernova recorded by astronomers in China and elsewhere, a cloud of debris lit from within by a spinning pulsar.
• Cassiopeia ACassiopeia A is the young remnant of a massive star that exploded unnoticed, and the brightest radio source in the sky beyond the Solar System.
• Tycho (SN 1572)Tycho is the remnant of the supernova that Tycho Brahe watched in Cassiopeia, the new star that helped overturn the idea of an unchanging sky.
• Kepler (SN 1604)Kepler is the remnant of the last supernova in the Milky Way seen with the naked eye, a new star in Ophiuchus studied by Johannes Kepler himself.
• SN 1006SN 1006 was the brightest supernova in recorded history, seen across the world, and its remnant is a thin, glowing shell in Lupus where cosmic rays are made.
• RCW 86 (SN 185)RCW 86 is a large supernova remnant in the southern Milky Way, the likely relic of the earliest supernova on record, a guest star noted by Chinese astronomers.
• 3C 58 (SN 1181)3C 58 is a remnant in Cassiopeia powered by a young pulsar, long linked with a guest star recorded in Chinese and Japanese chronicles, a link now in doubt.
• G1.9+0.3G1.9+0.3 is the youngest known supernova remnant in the Milky Way, a small expanding shell near the Galactic Centre whose explosion no one saw.
• Vela RemnantThe Vela Remnant is one of the nearest supernova remnants to the Sun, a vast web of glowing filaments in the southern sky with a bright pulsar at its heart.
• Cygnus LoopThe Cygnus Loop is a large old supernova remnant in Cygnus whose brightest filaments form the Veil Nebula, the shock of an explosion meeting the gas around it.
• Simeis 147Simeis 147, the Spaghetti Nebula, is a large, faint supernova remnant on the border of Taurus and Auriga, a tangle of thin filaments around a young pulsar.
• IC 443IC 443, the Jellyfish Nebula, is a supernova remnant in Gemini colliding with a molecular cloud, one of the sites that showed remnants make cosmic rays.
• Puppis APuppis A is a bright X-ray supernova remnant in the southern sky, seen behind the Vela Remnant, from which a neutron star is fleeing at high speed.
• Monoceros LoopThe Monoceros Loop is a large, old and faint supernova remnant in Monoceros, lying near the Rosette Nebula on the sky, its shell mapped by faint filaments.
• RX J1713.7-3946RX J1713.7-3946 is a supernova remnant in Scorpius that shines in X-rays and very high-energy gamma rays, a natural particle accelerator mapped from the ground.
• W44W44 is a supernova remnant in Aquila crashing into a molecular cloud, one of the sites where gamma rays showed supernovae accelerate cosmic-ray protons.
• W28W28 is a supernova remnant in Sagittarius, an old shell of shocked gas ploughing into the dense molecular clouds around it, where it lights up in gamma rays.
• W50 (SS 433)W50 (SS 433) is a vast supernova remnant in Aquila, stretched into a lopsided shape by the binary star at its centre, which fires two precessing jets.
• CTB 109CTB 109 is a supernova remnant in Cassiopeia shaped like a half-moon, its shell cut short by a molecular cloud, with a magnetar at its centre.
• MSH 15-52MSH 15-52 is a supernova remnant in Circinus around a young, fast-spinning pulsar whose wind blows an X-ray nebula shaped like an open hand.
• G21.5-0.9G21.5-0.9 is a young supernova remnant in Scutum, dominated by a bright pulsar wind nebula and used to calibrate X-ray telescopes in orbit.
• Sgr A EastSgr A East is a supernova remnant at the very centre of the Milky Way, an elongated shell that wraps around the black hole Sgr A* from behind.
• Ophiuchus CloudThe Ophiuchus Cloud is one of the nearest places where stars are being born, a dark cloud complex whose dense core around Rho Ophiuchi hides a young cluster.
• Lupus CloudThe Lupus Cloud is a nearby dark cloud in the southern constellation Lupus where small, Sun-like stars are forming quietly, without any massive stars among them.
• Chamaeleon CloudThe Chamaeleon Cloud is a dark cloud near the south celestial pole, one of the closest regions where low-mass stars are being born today.
• Corona AustralisThe Corona Australis star-forming region is a dark cloud south of Sagittarius where a young cluster, the Coronet, lights small blue reflection nebulae.
• Taurus CloudThe Taurus Cloud is the nearest large star-forming region, a web of dark filaments where small stars form one by one, far from any massive star.
• Perseus CloudThe Perseus Cloud is a molecular cloud in Perseus holding two young star clusters, among the nearest places where stars are born in groups rather than alone.
• Pipe NebulaThe Pipe Nebula is a dark cloud in Ophiuchus shaped like a smoker’s pipe, a silhouette of dust against the bright star clouds of the Galactic centre.
• Coma Star ClusterThe Coma Star Cluster is a sprawling open cluster in Coma Berenices, so close to us that its stars spread across a patch of sky wider than a fist.
• Rho OphiuchiRho Ophiuchi is a star and the cloud around it, one of the most colourful regions of the sky, where blue and golden dust surrounds an infant star cluster.
• Taurus Molecular CloudThe Taurus Molecular Cloud is the closest big nursery of stars, a quiet complex of dark filaments in Taurus and Auriga where only small stars are forming.
• Omicron Velorum ClusterThe Omicron Velorum Cluster is a bright young open cluster in Vela, a tight knot of blue-white stars around Omicron Velorum, visible to the naked eye.
• Southern PleiadesThe Southern Pleiades is a bright open cluster in Carina, a group of blue-white stars led by Theta Carinae and among the finest naked-eye clusters in the south.
• Corona Australis CloudThe Corona Australis Cloud is a long dark cloud in the southern sky, one of the nearest star-forming clouds, with a young cluster buried at its dense head.
• Alpha Persei ClusterThe Alpha Persei Cluster is a bright, scattered open cluster around the star Mirfak in Perseus, a group of young blue-white stars best seen in binoculars.
• Beehive (M44)The Beehive (M44), also called Praesepe, is an open cluster in Cancer, a misty patch to the naked eye that the first telescopes broke up into a swarm of stars.
• Chamaeleon ComplexThe Chamaeleon Complex is the family of dark clouds near the south celestial pole, one of the nearest regions forming low-mass stars, away from the Galactic plane.
• Helix NebulaThe Helix Nebula is one of the nearest planetary nebulae, the glowing outer layers of a dying Sun-like star in Aquarius, seen almost face-on like a giant eye.
• Lupus CloudsThe Lupus Clouds are a scattered complex of dark molecular clouds in Lupus and Scorpius, a nearby nursery of small stars on the edge of the Sco–Cen association.
• Ptolemy Cluster (M7)The Ptolemy Cluster (M7) is a bright open cluster near the sting of Scorpius, easy to see with the naked eye and described by Ptolemy in antiquity.
• Aquila RiftThe Aquila Rift is a long lane of dust that splits the summer Milky Way from Aquila through Serpens to Ophiuchus, a nearby cloud complex where stars are forming.
• M39M39 is a large, loose open cluster in Cygnus, a sprinkling of bright stars not far from Deneb on the sky, best seen in binoculars or a wide telescope field.
• Perseus Molecular CloudThe Perseus Molecular Cloud is a chain of cold gas and dust in Perseus, mapped in radio, that is forming clusters of young stars at both of its ends.
• Cepheus FlareThe Cepheus Flare is a complex of dark clouds rising out of the Milky Way’s plane in Cepheus, where a scattering of young stars is forming in dense cores.
• Dumbbell Nebula (M27)The Dumbbell Nebula (M27) is a bright planetary nebula in Vulpecula, the glowing shell of a dying star and the first planetary nebula ever discovered.
• NGC 752NGC 752 is an old open cluster in Andromeda, a loose scattering of stars near Almach that has outlived most clusters of its kind.
• California NebulaThe California Nebula is a long cloud of glowing hydrogen in Perseus, named for its outline, ionised by the hot star Menkib (Xi Persei) beside it.
• Butterfly Cluster (M6)The Butterfly Cluster (M6) is an open cluster near the tail of Scorpius whose brighter stars outline a butterfly with open wings, led by an orange giant.
• Crystal Ball NebulaThe Crystal Ball Nebula is a planetary nebula in Taurus around a bright central star, the object that convinced William Herschel some nebulae are not made of stars.
• M47M47 is a bright, loose open cluster in Puppis that went missing for a long time because Messier recorded its position wrongly, until it was matched to a known cluster.
• Wishing Well ClusterThe Wishing Well Cluster, NGC 3532, is a rich open cluster in Carina, bright enough to see by eye and scattered like coins glinting at the bottom of a well.
• Serpens CloudThe Serpens Cloud is a dark molecular cloud in Serpens Cauda where stars are forming right now, hidden from visible light and revealed by infrared telescopes.
• NGC 7027NGC 7027 is a young, dense planetary nebula in Cygnus, a dying star’s freshly shed envelope and the place where helium hydride was first found in space.
• Skull NebulaThe Skull Nebula, NGC 246, is a planetary nebula in Cetus whose hot central star belongs to a multiple system and whose shell ploughs through interstellar gas.
• Christmas Tree ClusterThe Christmas Tree Cluster, NGC 2264, is a very young cluster in Monoceros, still forming stars inside the gas that also shapes the Cone Nebula at its tip.
• Southern Ring NebulaThe Southern Ring Nebula, NGC 3132, is a planetary nebula in Vela whose true dying star, hidden in dust beside a brighter companion, was revealed by Webb.
• Ring Nebula (M57)The Ring Nebula, M57, is the best-known planetary nebula, a glowing shell cast off by a dying star in Lyra and seen nearly end-on, so it looks like a smoke ring.
• NGC 2438NGC 2438 is a planetary nebula in Puppis that seems to float inside the open cluster M46, though it is a chance alignment and not a member of the cluster.
• Monoceros R2Monoceros R2 is a giant molecular cloud in Monoceros lit by a group of reflection nebulae, with a massive young cluster still buried at its dusty core.
• Saturn NebulaThe Saturn Nebula, NGC 7009, is a planetary nebula in Aquarius whose thin side extensions recall the rings of Saturn seen edge-on through a small telescope.
• Ghost of JupiterThe Ghost of Jupiter, NGC 3242, is a planetary nebula in Hydra that looks like a pale blue-green disc about as wide in the sky as the planet Jupiter.
• Little Dumbbell (M76)The Little Dumbbell, M76, is a faint planetary nebula in Perseus, a bipolar shell named for its likeness to the larger and brighter Dumbbell Nebula, M27.
• Cat's Eye NebulaThe Cat’s Eye Nebula, NGC 6543, is a planetary nebula in Draco, the first whose spectrum was taken, proving that such nebulae are glowing gas and not stars.
• Spirograph NebulaThe Spirograph Nebula, IC 418, is a young planetary nebula in Lepus, a reddish oval whose fine looping texture resembles a pattern drawn with a spirograph.
• Rosette NebulaThe Rosette Nebula is a vast flower of glowing hydrogen in Monoceros, hollowed out at its centre by the hot young stars of the cluster NGC 2244 inside it.
• Northern Jewel BoxThe Northern Jewel Box, NGC 6231, is a young cluster of brilliant hot stars in Scorpius, the bright heart of an association of massive stars near Zeta Scorpii.
• M46M46 is a rich open cluster in Puppis, a dense field of faint stars with a small planetary nebula, NGC 2438, apparently set in its edge by chance alignment.
• Bow Tie NebulaThe Bow Tie Nebula, NGC 40, is a planetary nebula in Cepheus, a barrel-shaped shell around a hot, carbon-rich central star of the Wolf–Rayet type.
• Eskimo NebulaThe Eskimo Nebula, NGC 2392, is a planetary nebula in Gemini whose bright inner bubble and fringed outer disc suggest a face framed by a fur-lined hood.
• W3W3 is a giant star-forming complex in Cassiopeia, a radio-bright nest of newborn massive stars in the Perseus Arm, beside the Heart and Soul nebulae.
• Jewel BoxThe Jewel Box, NGC 4755, is a young open cluster in Crux whose blue-white stars and single red supergiant reminded John Herschel of a casket of gems.
• Maddalena's CloudMaddalena’s Cloud is a giant molecular cloud on the Canis Major–Monoceros border, notable for holding a great mass of gas while forming almost no stars.
• Wild Duck (M11)The Wild Duck Cluster, M11, is one of the richest and most compact open clusters known, a dense swarm of stars in front of the bright Scutum Star Cloud.
• M35M35 is a bright open cluster at the feet of Gemini, visible by eye from a dark site, with a much older and more distant cluster, NGC 2158, beside it in the sky.
• Draco DwarfThe Draco Dwarf is a faint dwarf spheroidal galaxy orbiting the Milky Way, a sparse cloud of ancient stars held together mostly by dark matter.
• Sculptor DwarfThe Sculptor Dwarf is a small spheroidal galaxy orbiting the Milky Way, the first of its kind ever found, made of old stars and dominated by dark matter.
• Carina DwarfThe Carina Dwarf is a faint spheroidal galaxy orbiting the Milky Way, notable for having formed its stars in separate bursts with long quiet spells between them.
• Fornax DwarfThe Fornax Dwarf is the most luminous of the Milky Way’s dwarf spheroidal galaxies, a satellite with its own globular clusters orbiting inside it.
• Leo ILeo I is a dwarf spheroidal galaxy among the most distant satellites of the Milky Way, lying almost behind Regulus, whose glare long made it hard to study.
• Homunculus NebulaThe Homunculus Nebula is the dusty bipolar cloud thrown off by Eta Carinae in its Great Eruption, two expanding lobes around one of the most massive stars known.
• VY CMa NebulaThe VY CMa Nebula is the dusty debris around VY Canis Majoris, a red hypergiant shedding its outer layers in arcs, knots and clumps as it nears its end.
• M32M32 is a compact elliptical galaxy orbiting Andromeda, small but unusually dense, with a supermassive black hole at its centre and a crowd of old stars.
• M110M110 is a dwarf elliptical galaxy orbiting Andromeda, larger and more diffuse than M32, holding a little dust and a sprinkle of young blue stars at its centre.

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