| Delete a Mark This option allows you to delete a Mark file. Click on it, and a menu listing all current mark files will appear; click on one, and, after checking to make sure you really want to delete it, Guide will delete that mark file. This item can be reached at any time via the | hotkey; or, you can reach it from within the File menu. Andromeda Andromeda is one of the oldest constellations in the sky. It represents a mythological princess, the daughter of Cepheus and Cassiopeia (also constellations). She was chained to a rock to be killed by the sea monster Cetus (also a constellation) as punishment for her mother's boast of being more beautiful than the Nerieds. She was rescued by Perseus (also a constellation). Perseus had recently killed Medusa, and by showing the severed head to Cetus, turned the creature to stone. All these constellations are in the same rough area of the sky. (The inclusion of Pegasus in the myth is a the creation of more modern writers.) Andromeda is most noted for containing M-31, the spiral galaxy nearest to our own (about 2 million light-years away.) A sharp-eyed observer will spot it as a fuzzy patch of light. Antlia Antlia, the Air Pump, is a creation of the French astronomer La Caille. It contains no stars of great note. Apus Apus, the Bird of Paradise, is one of twelve southern constellations created by Keyzer. Aquila Aquila, the Eagle, is named after the bird sent to carry Ganymede to the heavens in Roman mythology. It is a fairly prominent summer constellation. Aquarius Aquarius, the Water Bearer, is one of the 12 constellations in the zodiac, and is a fairly ancient grouping. The Egyptians believed that its rising just before sunrise brought water, and therefore fertility, to their land. Ara Ara, the Altar, is one of the few constellations that looks like the object it is named for. It contains only dim stars, and little of great interest. Aries Aries, the Ram, is one of the 12 constellations in the zodiac, represents the ram with the Golden Fleece, the goal of the Argonautic expedition. Auriga Auriga, the Charioteer, has also been represented as a bearded man carrying a goat, while the Greeks saw it as a lame man riding a horse. It may represent the god Neptune, who is often shown in a chariot drawn by sea horses. Bootes Bootes, the Herdsman, is one of the oldest constellations, mentioned in the Odyssey. Its brightest star, Arcturus, was one of the first noted to move by Edmund Halley (better known for Halley's Comet.) Caelum Caelum, the Chisel, is a small constellation formed by the French astronomer La Caille. Camelopardalis Camelopardalis, the Giraffe, occupies a huge part of the far northern sky. It is somewhat modern, formed by Bartschius in 1614. Despite its great extent, it has no bright stars. Capricornus Capricornus, the Goat, is one of the twelve constellations in the Zodiac. It was once the point where the Sun reached its lowest point in the sky, at the winter solstice, and therefore gave its name to the Tropic of Capricorn. Carina Carina, the Keel of a Ship, used to be part of Argo Navis, an enormous constellation since split into Carina, Puppis, and Vela. It contains Canopus, the second brightest star in the sky. Canopus cannot be seen from north of about the 38th parallel. Cassiopeia Cassiopeia is usually associated with the myth of Andromeda. It is one of the better-known groups, probably because its W shape makes it easy to find. She is usually drawn as being bound to a chair. Centaurus Centaurus, the Centaur, is noted in part for the globular cluster Omega Centauri, and also for its brightest star, Alpha Centauri, the star nearest to our own. This star is really two stars, one almost a twin of our own, the other a little dimmer and more orange. These two orbit one another every eighty years. A third, very dim star (Proxima Centauri, discovered in 1913) is about two degrees away, orbiting the other two in about a million years. Cepheus Cepheus is the mythological father of Andromeda. The constellation is best known for Delta Cephei, the original Cepheid variable. This star varies in brightness by about 1.2 magnitudes in a period of 5.4 days. Cetus Cetus, the Sea Monster, figures into the myth of Andromeda. Its most famous object is Omicron Ceti, or Mira, a prototype long period variable star. It ranges from below magnitude 10 to about mag 3, and sometimes brighter, in an irregular cycle of about 330 days. Cetus also contains Tau Ceti, a star similar to our own except dimmer, and a mere eleven light-years away. This has made it a favorite of those looking for extra- terrestrial life, one of the first subjects of the early radio searches, and a favorite of science fiction writers. Chamaeleon Chamaeleon, the Chameleon, is one of several formed by the astronomer Keyzer in the early 1600s. Circinus Circinus, the Compass, occupies a small piece of the southern sky. It contains little of note. Canis Major Canis Major, the Big Dog, is mostly noted for Sirius, the Dog Star. Sirius was important to the ancient Egyptians because it rose just before the Nile flooded. It is the brightest star in the sky, mostly because it is close to us (8.6 light-years). Canis Minor Canis Minor, the Little Dog, is, with Canis Major, one of the two dogs following at the heels of Orion. It is most noted for the star Procyon, a relatively nearby star (11.5 light-years). Cancer Cancer, the Crab, is one of the twelve Zodiacal constellations. Its most interesting objects are the two open clusters, M-44 (the Praesepe cluster) and M-67. Columba Columba, the Dove, was originally called Columba Noae, the Dove of Noah. It contains little of note. Coma Berenices Coma Berenices, Berenice's Hair, was named when an Egyptian Pharaoh's sister, Berenice, offered her severed hair to Venus if her husband returned safely from the Syrian wars. He did, and Zeus took the hair and placed it in the sky. Because the constellation is far from the plane of our own galaxy, it is easy to find many external galaxies here. Corona Australis Corona Australis, the Southern Crown, is one of the 48 constellations originally drawn up by Ptolemy in the 2nd century. Corona Borealis Corona Borealis, the Northern Crown, is a brighter, more northerly version of Corona Australis. The constellation contains two noted variable stars: R CrB, a star usually of magnitude 6 that sometimes drops down to magnitude 12, probably because of carbon particles in its atmosphere absorbing the light; and T CrB, a recurring nova. In legend, this crown was given to Ariadne, wife of Theseus, by the god Bacchus as a consolation after Theseus left her, and was placed in the sky after Ariadne's death. Crater Crater, the Cup, is associated with the myth of Corvus. It is very inconspicuous, but was one of the original 48 constellations of Ptolemy. Crux Crux, the Southern Cross, is, in area, the smallest constellation. It was made a constellation in the early 1600s, and is noted for being closely aligned to the South celestial Pole. The southeastern corner is mostly filled with the Coal Sack, an area of dust and gas that obscures stars behind it. Corvus Corvus, the Crow, is one of the 48 constellations originally drawn up by Ptolemy in the 2nd century. Several legends are attached to this constellation, among them, that being sent by Apollo with a cup to get water, he waited under a fig tree for the fruit to ripen. He then returned to the god carrying a water snake, alleging that this was the cause of his delay. In punishment for his lie, he was thrown into the sky with the Cup (Crater) and Snake (Hydra). Canes Venatici Canes Venatici, the Hunting Dogs, was set up in the late 17th century to fill in a gap between constellations. It is just south of Ursa Major. It contains three objects of note: M3, a globular cluster of over 10,000 stars in a sphere 65 light-years across; M-51, the famous Whirlpool Galaxy, and M-63, another spiral galaxy. Cygnus Cygnus, the Swan, is also called the Northern Cross. Its brightest star, Deneb Cygni (mixed Arabic and Latin for the Tail of the Swan), is 30,000 times brighter than the Sun. Only its great distance (1,600 light-years) makes it appear as dim as it does. Delphinus Delphinus, the Dolphin, is a compact, kite-shaped grouping with no notable objects in it. Dorado Dorado is supposed to represent a goldfish (not the small version found in fishtanks, but a larger ocean- dwelling fish). It contains the Large Magellanic Cloud, an irregular galaxy that orbits our own. The LMC was first noted by Europeans during Magellan's expedition. Draco Draco, the Dragon, was said to be the snake snatched by Minerva from the giants and whirled to the sky, or the monster whose teeth Jason sowed to raise the crop of armed men. One of its stars, Thuban, was the North Star about 2750 BC. Equuleus Equuleus, the Little Horse, dates back to the old constellations of the Babylonians. It doesn't contain anything of note. Eridanus Eridanus, the River, was the Nile to the Egyptians and the Euphrates to the Babylonians. The Greeks and Romans simply knew it as "the River". Its brightest star, Achernar, is at its southernmost end, invisible to those in northern latitudes. It is possibly the river used by Hercules to flush out the Augean stables. Fornax Fornax, the Chemical Furnace, was named by La Caille to be one of Sculptor's tools. Gemini Gemini, the Twins, is one of the twelve groups of the Zodiac. The Twins, Castor and Pollux, were the sons of Leda and Jupiter and brothers to Helen of Troy. They were appointed by Jupiter to be guardians of Rome, and were among the Argonauts with Jason. The constellation includes the noted open cluster M-35. Grus Grus, the Crane, is one of the groups formed by Keyzer in the late 1500s. Hercules Hercules probably dates back to the Sumerians. Their version was Gilgamesh. At the time (3000 BC), Hercules (or Gilgamesh) would have appeared upright; precession now leaves him head down. Hercules is associated with several other constellations. Hydra may represent the sea serpent he killed. Leo may represent the Nemean Lion. Eridanus may represent the river used to flush out the Augean stables. Cancer, Lupus, and Centaurus also figure into the Herculean labors. Alpha Herculis is a cool, reddish star, possibly as large as 60 AU across. If so, it's the largest known star. M-13, the Great Hercules Cluster, is also in this constellation. Horologium Horologium, the Clock, is one of several astronomical instrument constellations added by La Caille in the middle 1700s. It is supposed to be an old-style pendulum clock of the variety astronomers used at that time. Hydra Hydra is either derived from the unusual beast killed by Hercules, or (more probably) the water snake in the Corvus myth. It is, in area, the largest constellation. Hydrus Hydrus, the Sea Serpent, is a far-south creation of Keyzer in the late 1500s. Indus Indus, the (American) Indian, is another creation of Keyzer. None of its stars are very interesting, except possibly for Epsilon Indi, a star at the relatively nearby distance of 11.4 light-years. The constellation may refer to the Amazonian queen Hyppolyta, whose golden girdle was an objective of a labor of Hercules. Lacerta Lacerta, the Lizard, was created by the astronomer Hevelius in 1690, using outlying stars from Cygnus and Andromeda. Leo Leo, the Lion, is one of the twelve original groups in the Zodiac. Its western part, which resembles a sickle, is sometimes referred to separately as "the Sickle", in much the way that the Big Dipper is referred to separately from Ursa Major. Lepus Lepus, the Hare, is one of the 48 constellations originally recognized by Ptolemy. It lies just below Orion, and is supposedly being hunted by him. Libra Libra, the Scales, is one of the original twelve constellations in the Zodiac. It was originally the claws of Scorpius. Leo Minor Leo Minor, the Little Lion, is a faint group just above Leo. It was added by the astronomer Hevelius in the late 1600s. Lupus Lupus, the Wolf, is an ancient constellation. The name may be an erroneous translation of the Arabic Al Fahd, the Leopard or Panther. The constellation has undergone some change over time. It may originally have represented the Erymanthian boar, which Hercules and the Centaurs hunted. Lynx Lynx is another late-1600s creation of Hevelius. He named it thus because of the eyesight required to find much of anything in this barren area. Lyra Lyra, the Lyre, represents the instrument invented by Hermes and given to his half-brother, Apollo, who turned it over to his son Orpheus, the musician of the Argonauts, who used it to lure the Argonauts away from the music of the Sirens. Also, this lyre was used in Orpheus's failed attempt to rescue his wife, Eurydice, from Hades. After Orpheus' death, Jupiter put the lyre in the sky. Lyra was often described as either a vulture or a tortoise. Hermes made the first lyre by putting strings across a tortoise shell. Its brightest star, Vega, is a bluish-white star 27 light-years from us. Beta Lyrae is an interesting variable star, the prototypical example of the Beta Lyrae class of variable. Mensa Mensa, the Table, is another mid-18th century creation of La Caille. Microscopium Microscopium, the Microscope, is another example of a scientific instrument made constellation by La Caille in the mid-18th century. Monoceros Monoceros, the Unicorn, contains many telescopic clusters. It is noted for the irregular variable S Mon. Musca Musca, the Fly, was known as Apis, the Bee, in the Bayer catalog of 1603. It is a Keyzer constellation. Someone, possibly Halley (more noted for noticing that Halley's comet returns at 76-year intervals), changed it from a bee to a fly later on. Norma Norma, the Level or Square, was originally Norma et Regula, the Square and Level, and was created by La Caille to represent tools that Sculptor would use. Octans Octans, the Octant, contains the south celestial pole. It is a La Caille creation, named after the once important navigational device that was replaced by the sextant (also a constellation, Sextans). Ophiuchus Ophiuchus, the Serpent Handler, is usually associated with Aesculapius, the ship's surgeon on the Argo. He became so skilled after the voyage that he even returned the dead to life, including one case (Hippolyte) where the patient had been drawn and quartered. At Neptune's request, Aesculapius glued the pieces together and restored them to life. Such successes, and the attempt to revive the dead Orion, led Pluto to worry he might be put out of business, so he induced Jove to strike Aesculapius with a thunderbolt and place him in the sky. Orion Orion, the Hunter, is one of the best known groups, largely because its bright stars and belt make it easy to pick out. It contains many interesting objects: the Orion Nebula around the "sword"; Betelgeuse, one of the better-known and studied red giants; and a large number of young, blue- and white-hot stars. It is accompanied by the Hunting Dogs, Canis Major and Canis Minor, going after the Hare, Lepus. Orion is supposed to have boasted that no animal could kill him. Jupiter therefore sent a scorpion to do the job, and then put Orion and the scorpion, Scorpius, in opposite parts of the sky. Pavo Pavo, the Peacock, is a southern creation of Keyzer. It has one interesting globular cluster, NGC 6752, and a Cepheid variable, Kappa Pavonis, which varies from magnitude 4.0 to 5.5 in just over nine days. Pegasus Pegasus, the Winged Horse, was the mythological child of Neptune and Medusa, raised by Neptune from Medusa's blood when it fell into the sea after Perseus severed her head. Of the four stars making up the Square of Pegasus, that in the northeast corner, Alpheratz, is now considered to be in Andromeda. It thus has been labeled Alpha Andromeda or Delta Pegasi. Perseus Perseus figures prominently in the legends of Andromeda. It is one of the earliest named groups. The most interesting object here is Algol (Arabic for the Demon). It is an eclipsing binary, dropping by about one magnitude for a few hours every 2.867315 days. Circling the two eclipsing stars is a third, dimmer star that completes an orbit around the others every 23 months. Phoenix Phoenix is another Keyzer constellation, created in the late 1500s. It is not a very prominent constellation. Pictor Pictor, the Easel, is another of Sculptor's tools. A nova, RR Pictoris, flared up near to Alpha Pictoris in 1925; it is still visible, though it is difficult to find see of significance without a large telescope. Piscis Austrinus Piscis Austrinus, the Southern Fish, lies in a relatively barren part of the sky. Its brightest star, Fomalhaut, is at the fairly close distance of 23 light-years. Pisces Pisces, the Two Fish, is an ancient constellation and is part of the zodiac. It is thought that its dual nature may make a sort of "thirteenth sign". The Babylonians had a twelve-month, 360-day calendar; to get the years to come out evenly, they inserted a thirteenth month every six years, and it is thought that the extra fish may represent this thirteenth month. Puppis Puppis, the Stern of a Ship, was once part of the giant constellation Argo Navis, since split into Puppis, Vela (the sail), and Carina (the keel). Its brightest star, Zeta Puppis, lies at the considerable distance of 2,400 light-years. It is an enormous blue- hot star (spectral type O5). Pyxis Pyxis, the Compass, is associated with the groups making up Argo Navis, Puppis the Stern, Vela the Sail, and Carina the Keel. It contains no bright stars. Reticulum Reticulum, the Grid, was created by Isaak Habrecht of Germany as the Rhombus. It is supposed to represent the target grid used in telescopes to find stellar positions. Sculptor Sculptor is a La Caille creation of the mid-18th century. He is usually depicted as surrounded by tools, such as Caelum (the Chisel), Pictor (the Easel), Fornax (the Furnace), and Norma (the Square). Scorpius Scorpius, the Scorpion, is a constellation of the zodiac. Its most interesting object is Antares, meaning "rival to Mars" (due to its deep red color). In myth, it represents the scorpion sent by Jupiter to kill Orion. Scutum Scutum, the Shield, contains M-11, the Wild Duck cluster. Serpens Serpens represents the serpent being handled by Ophiuchus, the Serpent Handler. It is the only group split in half, the eastern part being Serpens Cauda (the tail), the western Serpens Caput (the head), with Ophiuchus in between. Sextans Sextans, the Sextant, was added by Hevelius. It contains little of note. It was here that De Rheita thought he had found a representation of the sacred handkerchief of Saint Veronica, leading Sir John Herschel to note that "many strange things were seen among the stars before the use of powerful telescopes became common." Sagitta Sagitta, the Arrow, although an ancient constellation, holds little of note. Sagittarius Sagittarius, the Archer, is one of the twelve constellations of the zodiac. It marks the direction to the center of our Galaxy, and many interesting objects can be found there. It contains a vast array of clusters, nebulae, and variable stars. It is usually found either by the five stars making up the "Milk Dipper", a small, upside down group, or the Teapot, which is the Milk Dipper plus three other stars.