Kitt Peak Nightly Observing Program
Splendors of the Universe on YOUR Night!
Many pictures are links to larger versions.
Click here for the “Best images of the OTOP” Gallery and more information.
The Big Dipper (also known as the Plough) is an asterism consisting of the seven brightest stars of the constellation Ursa Major. Four define a “bowl” or “body” and three define a “handle” or “head”. It is recognized as a distinct grouping in many cultures. The North Star (Polaris), the current northern pole star and the tip of the handle of the Little Dipper, can be located by extending an imaginary line from Big Dipper star Merak (β) through Dubhe (α). This makes it useful in celestial navigation.
Constellation Ursa Minor is colloquially known in the US as the Little Dipper, because its seven brightest stars seem to form the shape of a dipper (ladle or scoop). The star at the end of the dipper handle is Polaris, the North Star. Polaris can also be found by following a line through two stars in Ursa Major—Alpha and Beta Ursae Majoris—that form the end of the ‘bowl’ of the Big Dipper, for 30 degrees (three upright fists at arms’ length) across the night sky.
The Summer Triangle is an asterism involving a triangle drawn on the northern hemisphere’s celestial sphere. Its defining vertices are the stars Altair, Deneb, and Vega, which are the brightest stars in the constellations Aquila, Cygnus, and Lyra, respectively.
The brightest stars in the zodiac constellation Sagittarius form the shape of a teapot, complete with lid, handle, and spout. The plane of the Milky Way runs through Sagittarius, and just over the spout and lid of the teapot, making it look as if steam is rising from the spout of the teapot. The center of our Milky Way galaxy is in the direction of this starry steam.
Also called Cr 399, or Brocchi’s Cluster, this group of stars might remind you of a closet. The stars that make up The Coarhanger are not a part of a cluster, but instead, have randomly arranged themselves in a coathanger-like shape. Chaotic stellar orbital motion can sometimes make interesting shapes!
Andromeda was the princess of myth who was sacrificed by her parents to the sea monster Cetus. Fortunately, the hero Perseus came along to save her, and they were eventually married. The constellation Andromeda is host to the Andromeda Galaxy. Although there are smaller, dwarf galaxies that are closer to our galaxy, Andromeda is the closest big galaxy like our own; in fact, it’s bigger.
The brightest star in Aquila is Altair—one of the brightest starts in the summer sky, and a point of The Summer Triangle. The name aquila is latin for eagle, and the brightest stars in this constellation do seem similar to the shaape of an eagle standing upright with its wings spread out at its sides. Altair is at the head, or more precisely, the eye of the eagle. In Greek mythology, Aquila carried Zeus’s thunderbolts.
Cassiopeia is widely recognized by its characteristic W shape, though it may look like an M, a 3, or a Σ depending on its orientation in the sky, and your position on Earth. However it’s oriented, once you’ve come to know its distinctive zig-zag pattern, you’ll spot it with ease. The plane of the Milky Way runs right through Cassiopeia, so it’s full of deep sky objects—in particular, a lot of open star clusters. Cassiopeia is named for the queen form Greek mythology who angered the sea god Poseidon when she boasted that her daughter Andromeda was more beautiful than his sea nymphs.
Cygnus is a large constellation, prominent in the Northern Hemisphere. Its name comes from the Greek for “Swan” and can be imagined as a giant, celestial swan, flying overhead, with its wings fully extended. The brightest star in Cygnus is Deneb, which is one of the brightest stars in the sky, and a whopping 800 lightyears away! Deneb is one point of an asterism called the Summer Triangle—three very bright stars that form a large triangle shape prominent in the Northern hemisphere summer skies.
Lyra is a small, but notable constellation. It is host to Vega—the fifth brightest star in the sky (or sixth, counting the Sun). Not far from Vega is Messier object 57—the Ring Nebula, which is perhaps the best known planetary nebula in our sky. Lyra’s name is Greek for lyre—a kind of harp.
Sagittarius, the archer, is often depicted as a centaur wielding a bow and arrow. Within Sagittarius, is a fairly recognizable teapot shape known to many simply as The Teapot (the teapot is not a true constellation, but an asterism). The plane of the Milky Way passes through Sagittarius, and in fact, the center of the Milky Way is in the direction of the westernmost edge of this constellation—just above the spout of The Teapot. With the plane of the Milky Way passing through, there are a plethora of deep sky objects to be found in Sagittarius.
Both the plane of the Solar System (called the ecliptic) and the plane of the Milky Way pass through Scorpius—the scorpion. As a result, you can find both the planets of our Solar System (which move along the ecliptic), and many kinds of deep sky objects in this constellation. Scorpius’s brightest star, Antares, is also known as the Heart of the Scorpion, because of it’s reddish hue and location in the chest of the scorpion. Being both red in color, and near the ecliptic, Antares is a rival of sorts to the planet Mars, which is also reddish in color, and occasionally passes through Scorpius. The name Antares means “opposing Mars”.
Ursa Major, or, the Big Bear, is one of the best known and most well recognized constellations, but you might know it by a different name. Contained within the boundaries of the constellation Ursa Major is the Big Dipper, which is not a true constellation, but an asterism. The Big Dipper is useful for finding both the North Star and the bright star Arcturus. Follow the curve of the handle to “arc to Arcturus” and use to two stars in the dipper opposite the handle to point to the North Star.
Ursa Minor, the Little Bear, is much fainter than it’s companion the Big Bear, Ursa Major. Within Ursa Minor is the well known asterism The Little Dipper. The end of the tail of the bear, or the end of the handle of the dipper, is a star called Polaris—the Pole Star, or the North Star. This special star happens to sit at the point where the Earth’s axis of rotation intersects the sky
M8 Lagoon Nebula
M8: The “Lagoon Nebula.” A huge cloud of gas and dust beside an open cluster of stars (NGC 6530). The Lagoon is a stellar nursery, 4,100 lightyears away, towards the galactic core.
M31 Andromeda Galaxy
The Andromeda Galaxy is our nearest major galactic neighbor. It is a spiral galaxy 2,500,000 light-years away, and has a diameter of 220,000 light-years. This galaxy contains as much material as 1.5 trillion suns.
Near the top of the “teapot” in Sagittarius, M22 is one of the brightest globular star clusters in our sky, and therefore, was probably the first globular cluster ever discovered. Its 80,000 stars span a diameter of about 100 light-years.
The ecliptic is a path in the sky, forming a great circle around the Earth, which the Sun and other planets of the Solar System move along. It is formed where the plane of the Solar System intersects with the Earth’s sky.
Quick streaks of light in the sky called meteors, shooting stars, or falling stars are not stars at all: they are small bits of rock or iron that heat up, glow, and vaporize upon entering the Earth’s atmosphere. When the Earth encounters a clump of many of these particles, we see a meteor shower lasting hours or days.
That clumpy band of light is evidence that we live in a disk-shaped galaxy. Its pale glow is light from about 200 billion suns!
The “Double Cluster” (NGC 884 and NGC 869) is a pair of two open star clusters that are a treat for binoculars and telescopes alike. Each is a congregation of many hundreds of stars, around 50-60 light-years in diameter. These clusters are both about 7,500 light-years away.
M7 Ptolemy Cluster
M7, also known as the “Ptolemy Cluster” is an open star cluster near the “stinger” of Scorpius. It is a group of suns in a gravitational dance, 25 light-years across and about 1,000 light-years away.
Jupiter is the largest planet in the Solar System, a “gas giant” 11 Earth-diameters across. Its atmosphere contains the Great Red Spot, a long-lived storm 2-3 times the size of the Earth. The 4 large Galilean satellites and at least 63 smaller moons orbit Jupiter.
The same side of the Moon always faces Earth because the lunar periods of rotation and revolution are the same. The surface of the moon is covered with impact craters and lava-filled basins. The Moon is about a fourth of Earth’s diameter and is about 30 Earth-diameters away.
Mizar & Alcor
In the handle of the Big Dipper, Mizar & Alcor (ζ & 80 Ursae Majoris) or the “Horse & Rider” form a naked-eye double star. They are traveling through space together about 80 light-years away from us, separated by about a light-year. However, it is unknown if they are actually gravitationally bound to each other. A telescope splits Mizar itself into two stars, but these both are again doubles, bringing the total in this system to six.
Thank you for joining me this evening! I hope you enojoyed our dark skies, and I hope we will see you again soon!!
The web page for the program in which you just participated is at
Nightly Observing Program. Most of the above images were taken as
the Overnight Telescope Observing Program. For more information on this unique experience please visit Overnight Telescope Observing Program.
Copyright © 2019 Kitt Peak Visitor Center