Explore the Night Sky
Constellations
Learn about the most famous constellations.
Orion
Ursa major
Scorpius
Ursa minor
Cassiopeia
Leo
Cygnus
Taurus
Pagasus
Canis major
Aquarius
Lyra
Centaurus
Andromeda
Sagittarius
Stargazing Tips
1. Move away from city lights
Cities are filled with light pollution caused by streetlamps, buildings and cars that drown out dimmer stars and planets in the sky.
2. Find a clear spot where you can see as close to the horizon as possible
Make sure tall buildings and trees are not blocking your view as you stargaze. Getting higher up on mountain tops can give you a great vantage point.
3. Check the weather forecast
Nothing ruins a night of stargazing like the sudden appearance of clouds. Also make sure to dress for the weather: nights can get chilly all year round!
Star Finder (click to enlarge)
Star Classification
Stars are classified by their spectral type, which reflects their temperature and the light they emit. The most widely used classification system is the Morgan–Keenan (MK) system, which groups stars into seven main categories based on their surface temperature, color, and spectral lines. These categories are: O, B, A, F, G, K, and M. Here’s a breakdown of each:
O-Type Stars
Temperature: > 30,000 K
Color: Blue
Characteristics: O-type stars are extremely hot, bright, and massive. They emit large amounts of ultraviolet light and have short lifespans due to their high energy output. These stars are rare but very influential in shaping the surrounding interstellar medium.
Examples: Zeta Puppis, Theta1 Orionis C
B-Type Stars
Temperature: 10,000 – 30,000 K
Color: Blue-White
Characteristics: B-type stars are slightly cooler than O-types but still very bright and luminous. They have strong hydrogen spectral lines and tend to form in large clusters. These stars also have short lives, typically ending in supernovae.
Examples: Rigel, Spica
A-Type Stars
Temperature: 7,500 – 10,000 K
Color: White
Characteristics: A-type stars are white in color and have strong hydrogen lines in their spectra. They are among the more common stars visible to the naked eye and are often seen in the main sequence stage.
Examples: Sirius, Vega
F-Type Stars
Temperature: 6,000 – 7,500 K
Color: Yellow-White
Characteristics: F-type stars have moderate temperatures and show metal lines (like calcium) in their spectra. These stars are stable and have relatively long lifespans compared to the hotter types.
Examples: Procyon, Canopus
G-Type Stars
Temperature: 5,200 – 6,000 K
Color: Yellow
Characteristics: G-type stars, like our Sun, are moderate in size and temperature. They emit a yellowish light and are rich in elements heavier than helium. G-type stars often live long enough to allow for the development of planetary systems.
Examples: The Sun, Alpha Centauri A
K-Type Stars
Temperature: 3,700 – 5,200 K
Color: Orange
Characteristics: K-type stars are cooler and more orange than G-type stars. They have long lifespans and are more common in the universe. These stars are ideal for potentially hosting planets with life due to their stability and longevity.
Examples: Arcturus, Aldebaran
M-Type Stars
Temperature: < 3,700 K
Color: Red
Characteristics: M-type stars, also known as red dwarfs, are the coolest and most common stars in the universe. Despite their dimness, they have extremely long lifespans, often lasting trillions of years. Many planets have been found orbiting M-type stars.
Examples: Proxima Centauri, Barnard's Star
Famous Stars
Throughout history, certain stars have held special significance in navigation, mythology, and astronomy. Here is a list of some of the most famous stars and their importance:
Polaris (North Star)
Constellation: Ursa Minor
Significance: Polaris is perhaps the most famous navigational star, used for centuries to find true north. It is almost directly aligned with Earth's rotational axis, making it appear nearly stationary in the sky, while other stars rotate around it.
Sirius (Dog Star)
Constellation: Canis Major
Significance: Sirius is the brightest star in the night sky and was historically significant to ancient civilizations such as the Egyptians, who used its rising to predict the flooding of the Nile. Its name comes from the Greek word for "glowing."
Betelgeuse
Constellation: Orion
Significance: Betelgeuse is a red supergiant star and one of the largest visible stars in the sky. It marks the shoulder of Orion the Hunter. Due to its size and variability, it is expected to go supernova within the next 100,000 years.
Rigel
Constellation: Orion
Significance: Rigel is a bright blue supergiant star, representing Orion’s foot. It is one of the most luminous stars in our galaxy and often studied for its unique properties.
Alpha Centauri
Constellation: Centaurus
Significance: Alpha Centauri is the closest star system to Earth, just 4.37 light-years away. It consists of three stars, including Proxima Centauri, the nearest known exoplanetary host. It has been a target of interest for space exploration.
Antares
Constellation: Scorpius
Significance: Antares is a red supergiant and one of the brightest stars in the sky. Its name means "rival of Mars" due to its reddish color. It marks the heart of the scorpion in the constellation Scorpius.
Vega
Constellation: Lyra
Significance: Vega is the fifth-brightest star in the night sky and one of the cornerstones of the Summer Triangle asterism. It was once the northern pole star and will be again due to the precession of the Earth's axis.
Aldebaran
Constellation: Taurus
Significance: Aldebaran is the eye of the bull in the constellation Taurus and one of the brightest stars in the night sky. It is an important reference star and has been mentioned in various cultural mythologies.
Capella
Constellation: Auriga
Significance: Capella is one of the brightest stars visible from Earth and has been used in navigation. It represents the she-goat in mythology, often associated with the myth of the golden fleece.
Arcturus
Constellation: Boötes
Significance: Arcturus is one of the brightest stars visible from Earth and can be found by following the curve of the Big Dipper’s handle. It has been used as a guiding star for sailors and is known for its orange hue.
Procyon
Constellation: Canis Minor
Significance: Procyon is part of the Winter Triangle and is the eighth-brightest star in the night sky. Its name means "before the dog" in Greek, as it rises before Sirius, the Dog Star.
Altair
Constellation: Aquila
Significance: Altair is part of the Summer Triangle asterism and is one of the closest visible stars to Earth. It has featured prominently in various mythologies, including the story of the cowherd and the weaver girl in Chinese folklore.
Fomalhaut
Constellation: Piscis Austrinus
Significance: Fomalhaut is one of the brightest stars in the southern hemisphere and has been a significant navigational star. It is part of a young planetary system and is one of the few stars with directly imaged exoplanets.
Spica
Constellation: Virgo
Significance: Spica is the brightest star in Virgo and has been associated with agriculture and harvest in many cultures. It is part of an eclipsing binary system and is a key star used for sky orientation.
Deneb
Constellation: Cygnus
Significance: Deneb is the brightest star in Cygnus and forms one corner of the Summer Triangle. It is one of the largest white supergiants known and lies at a great distance, making it one of the most luminous stars visible.