Spring Triangle
Encyclopedia
The Spring Triangle is an astronomical asterism
involving an imaginary triangle drawn upon the celestial sphere
, with its defining vertices at Arcturus, Spica
, and alternately Denebola
or Regulus
. This triangle connects the constellation
s of Boötes
, Virgo
, and Leo
. It is visible in the northern hemisphere
night sky between March and May.
It forms part of a larger Spring asterism called the Great Diamond
.
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
involving an imaginary triangle drawn upon the celestial sphere
Celestial sphere
In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the Earth and rotating upon the same axis. All objects in the sky can be thought of as projected upon the celestial sphere. Projected upward from Earth's equator and poles are the...
, with its defining vertices at Arcturus, Spica
Spica
Spica is the brightest star in the constellation Virgo, and the 15th brightest star in the nighttime sky. It is 260 light years distant from Earth...
, and alternately Denebola
Denebola
Denebola is the second brightest star in the constellation Leo. It is an A-class star that is about distant from earth, and has a luminosity about twelve times that of the sun. Its apparent magnitude is 2.14...
or Regulus
Regulus
Regulus is the brightest star in the constellation Leo and one of the brightest stars in the night sky, lying approximately 77.5 light years from Earth. Regulus is a multiple star system composed of four stars which are organized into two pairs...
. This triangle connects the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
s of Boötes
Boötes
Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning herdsman or plowman...
, Virgo
Virgo
-Astronomy:* Virgo Cluster, a cluster of galaxies in the constellation Virgo* Virgo , a constellation* Virgo Stellar Stream, remains of a dwarf galaxy* Virgo Supercluster, a galactic supercluster-Surname:* Virgo...
, and Leo
LEO
LEO as an initialism may refer to:* Low Earth orbit, a satellite path* Law enforcement officer, an official* Louisville Eccentric Observer, a newspaper* LEO , an electronic device* LEO , a lunar mission...
. It is visible in the northern hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
night sky between March and May.
It forms part of a larger Spring asterism called the Great Diamond
Great Diamond
The Great Diamond or Virgin's Diamond/Diamond of Virgo is an asterism. It is composed of the stars Cor Caroli , Denebola , Spica , and Arcturus...
.