Carina Nebula

Lore & Background

The Carina Nebula was discovered by Nicolas-Louis de Lacaille on 25 January 1752. Its dimensions are 120×120 arcminutes centered on coordinates of right ascension 10h 45m 08.5s and declination −59° 52′ 04″. In modern times it is calculated to be around 8,500 light-years (2,600 pc) from Earth. The nebula has within its boundaries the large Carina OB1 association and several related open clusters. Carina OB1 encompasses the star clusters Trumpler 14 and Trumpler 16. Trumpler 14 is one of the youngest known star clusters at half a million years old and contains stars like the O2 supergiant HD 93129A. Trumpler 16 is the home of many extremely luminous stars, such as WR 25 and the Eta Carinae star system. Trumpler 15, Collinder 228, Collinder 232, NGC 3324, and NGC 3293 are also considered members of the association. NGC 3293 is the oldest and furthest from Trumpler 14, indicating sequential and ongoing star formation. The nebula was selected as one of five cosmic objects observed by the James Webb Space Telescope, as part of the release of its first official science images. A detailed image was made of an early star-forming region of NGC 3324 known as the Cosmic Cliffs.

In Their Own Story

Eta Carinae is a highly luminous hypergiant star. Estimates of its mass range from 100 to 150 times the mass of the Sun, and its luminosity is about four million times that of the Sun. This object is currently the most massive star that can be studied in great detail because of its location and size. In 2006, Eta Carinae still had the highest confirmed luminosity, based on data across a broad range of wavelengths. Eta Carinae's effect on the nebula is directly visible. Dark globules and some other less visible objects have tails pointing directly away from the massive star. The entire nebula would have looked very different before the Great Eruption in the 1840s, which surrounded Eta Carinae with dust, drastically reducing the amount of ultraviolet light it put into the nebula. Within the large bright nebula is a much smaller feature, immediately surrounding Eta Carinae itself, known as the Homunculus Nebula (from Latin meaning Little Man). It is believed to have been ejected in an enormous outburst in 1841, which briefly made Eta Carinae the second-brightest star in the sky. The Homunculus Nebula is a small H II region, with gas shocked into ionized and excited states. It also absorbs much of the light from the extremely luminous central stellar system and re-radiates it as infrared (IR). It is the brightest object in the sky at mid-IR wavelengths.

Reader's Guide

The Carina Nebula is located in the constellation Carina, approximately 8,500 light-years (2,600 pc) from Earth. Its dimensions are 120×120 arcminutes. It was discovered by Nicolas-Louis de Lacaille on 25 January 1752 from the Cape of Good Hope. The nebula is one of the largest diffuse nebulae in Earth's sky, four times as large as and even brighter than the famous Orion Nebula, but much less well known due to its location in the southern sky. Key objects within the nebula include the Eta Carinae star system, the Homunculus Nebula, the Keyhole Nebula (a small dark cloud of cold molecules and dust), the Defiant Finger (a small Bok globule), and the open clusters Trumpler 14, Trumpler 15, and Trumpler 16. The nebula was selected as one of five cosmic objects observed by the James Webb Space Telescope, as part of the release of its first official science images.

Did You Know?

• The Carina Nebula is approximately 8,500 light-years (2,600 pc) from Earth.
• It was discovered by Nicolas-Louis de Lacaille on 25 January 1752 from the Cape of Good Hope.
• The nebula is four times as large as and even brighter than the famous Orion Nebula.
• Eta Carinae's luminosity is about four million times that of the Sun, and its mass ranges from 100 to 150 times the Sun's mass.
• The Homunculus Nebula was ejected in an enormous outburst in 1841, briefly making Eta Carinae the second-brightest star in the sky.