Click on image for full size
Arcturus: Orange Giant
What's in a Name: || Greek for "Bearkeeper". The bear is the constellation Ursa Major (the Great Bear).
|Claim to Fame:|| 4th brightest star in the sky. The reddish light of Arcturus striking a photoelectric cell marked the beginning of the 1934 Chicago World's Fair.
|Type of Star:|| Orange Giant (K2 III Spectral Class),
surface temperature 4400K. Fusing helium to carbon and oxygen in its core.
|How Far Away:|| 37 light years away
|How Big:|| 18 times larger than the sun, 4 times the sun's mass
|How Bright:|| 105 times the sun's luminosity (Mv=-0.3)
|Where to View:|| Brightest star in the constellation Bootes, the Herdsman (Star Map).
|When to View:|| April through August from Northern middle latitudes
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
In the 1960's, the United States launched some satellites to look for very high energy light, called Gamma Rays. Gamma Rays are produced whenever a nuclear bomb explodes. The satellites found many bursts...more
During the early 1900's, which is not very long ago, astronomers were unaware that there were other galaxies outside our own Milky Way Galaxy. When they saw a small fuzzy patch in the sky through their...more
Neutron Stars are the end point of a massive star's life. When a really massive star runs out of nuclear fuel in its core the core begins to collapse under gravity. When the core collapses the entire star...more
Spiral galaxies may remind you of a pinwheel. They are rotating disks of mostly hydrogen gas, dust and stars. Through a telescope or binoculars, the bright nucleus of the galaxy may be visible but the...more
When stars like our own sun die they will become white dwarfs. As a star like our sun is running out of fuel in its core it begins to bloat into a red giant. This will happen to our sun in 5 Billion years....more
What's in a Name: Arabic for "head of the demon" Claim to Fame: Represents Medusa's eye in Perseus. A special variable star that "winks" every 3 days. Type of Star: Blue-white Main Sequence Star, and...more
What's in a Name: Nicknamed the "Pup" because it is the companion to Sirius, "the Dog Star" Claim to Fame: Highly compressed white dwarf remnant. Density about 50,000 times that of water. It has approximately...more