Observing Carina the Keel
Home to Second Brightest Star and the Homunculus Nebula
Carina is a constellation famous for a few notable objects. One is the star Canopus, the second brightest star as seen from Earth, and the other is the nebula surrounding the star Eta Carinae. The constellation Carina was once part of a larger constellation named Argo Navis, the ship of Jason and the Argonauts. It has been divided into three parts: Carina the Keel, Vela the Sails, and Puppis the Stern. The most southerly part of Carina is about 20 degrees from the South Celestial Pole.
Stars of Carina the Keel
The brightest star in Carina, Canopus, is also the second brightest star in the sky as seen from Earth. Canopus, or Alpha Carinae, shines at magnitude -0.62 from a distance of 313 light-years. This supergiant star is occasionally visible from southerly locations in the Northern Hemisphere, such as Florida in winter.
Two other stars in Carina are bright enough to reach 1st magnitude. The brighter of the two is Beta Carinae, or Miaplacidus at magnitude 1.67. It lies about 20 degrees from the South Celestial Pole. Miaplacidus shines from a distance of 111 light-years.
Between Alpha and Beta and forming a triangle with them is the third brightest star in Carina, Epsilon Carinae, or Avior. It shines at magnitude 1.86 from a distance of 632 light-years, making it the farthest of the three.
Deep-Sky Objects in Carina
The most famous deep-sky object in Carina is undoubtedly the great Eta Carinae Nebula. It is also referred to as NGC 3372, the Keyhole Nebula, and the Homunculus Nebula. It lies on the opposite side of the constellation from Canopus. Eta Carina is an unusual star that has been undergoing periodic outbursts. It is the current best candidate for a star that may soon go supernova. Eta Carinae lies about 10,000 light-years away but inside our own Milky Way Galaxy. This large, diffuse nebula shines at 1st magnitude.
The portion of Eta Carinae known as the Homunculus Nebula is the inner portion that shows up in professional photos as a distinctive dual-lobed shell of an explosion. This explosion was first viewed in 1841, when it briefly made Eta Carina the second brightest star in the night sky.
A popular open cluster in Carina is IC 2602 and sometimes referred to as the Southern Pleiades. This second magnitude grouping is centered on the star Theta Carinae, which lies just four and a half degrees from Eta Carinae. About 60 stars lie within the area and less than 500 light-years from Earth.
