Eta Carinae, formerly known as Eta Argus, is a stellar system containing at least two stars with a combined luminosity greater than five million times that of the Sun, located around 7,500 light-years distant in the constellation Carina. Previously a 4th-magnitude star, it brightened in 1837 to become brighter than Rigel, marking the start of its so-called "Great Eruption". It became the second-brightest star in the sky between 11 and 14 March 1843 before fading well below naked-eye visibility after 1856. In a smaller eruption, it reached 6th magnitude in 1892 before fading again. It has brightened consistently since about 1940, becoming brighter than magnitude 4.5 by 2014.
The Trifid Nebula is an H II region in the north-west of Sagittarius in a star-forming region in the Milky Way's Scutum-Centaurus Arm. It was discovered by Charles Messier on June 5, 1764. Its name means 'three-lobe'. The object is an unusual combination of an open cluster of stars, an emission nebula, a reflection nebula, and a dark nebula. Viewed through a small telescope, the Trifid Nebula is a bright and peculiar object, and is thus a perennial favorite of amateur astronomers.
The Orion Arm, also known as the Orion–Cygnus Arm, is a minor spiral arm within the Milky Way Galaxy, spanning 3,500 light-years in width and extending roughly 10,000 light-years in length. This galactic structure encompasses the Solar System, including Earth. It is sometimes referred to by alternate names such as the Local Arm, Orion Bridge, and was previously identified as the Local Spur and Orion Spur. It should not be confused with the outer terminus of the Norma Arm, known as the Cygnus Arm.
The Carina Nebula or Eta Carinae Nebula is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky Way galaxy. The nebula is approximately 8,500 light-years (2,600 pc) from Earth.
NGC 6231 is an open cluster in the southern sky located half a degrees north of Zeta Scorpii. NGC 6231 is part of a swath of young, bluish stars in the constellation Scorpius known as the Scorpius OB1 association. The star Zeta1 is a member of this association, while its brighter apparent partner, Zeta2, is only 150 ly from Earth and so is not a member.
HD 93129 is a triple star system in the Carina Nebula, with all three components being hot O class stars amongst the most luminous stars in the Milky Way. It is the dominant member of the Trumpler 14 star cluster, a young star cluster within the Carina OB1 stellar association that harbors other super-luminous stars, like Eta Carinae and WR 25.
NGC 6357 is a diffuse nebula near NGC 6334 in the constellation Scorpius. The nebula contains many proto-stars shielded by dark discs of gas, and young stars wrapped in expanding "cocoons" or expanding gases surrounding these small stars. It is also known as the Lobster Nebula. This nebula was given the name War and Peace Nebula by the Midcourse Space Experiment scientists because of its appearance, which, in infrared images the bright, western part resembles a dove, while the eastern part looks like a skull. A petition by anime fans to rename it as the Madokami nebula, due to resemblance with a character, did not prosper.
HD 93205, or V560 Carinae, is a binary stellar system, in the Carina Nebula in the constellation Carina. It consists of two massive O-stars that revolve around each other in 6 days.
IC 5146 is a reflection/emission nebula and Caldwell object in the constellation Cygnus. The NGC description refers to IC 5146 as a cluster of 9.5 mag stars involved in a bright and dark nebula. The cluster is also known as Collinder 470. It shines at magnitude +10.0/+9.3/+7.2. Its celestial coordinates are RA 21h 53.5m, dec +47° 16′. It is located near the naked-eye star Pi Cygni, the open cluster NGC 7209 in Lacerta, and the bright open cluster M39. The cluster is about 4,000 ly away, and the central star that lights it formed about 100,000 years ago; the nebula is about 12 arcmins across, which is equivalent to a span of 15 light years.
HD 93250 is a highly luminous hot blue binary star in the Carina Nebula in the constellation Carina.
RT Carinae, also known as CD-58 3538, is a variable star in the Carina Nebula in the constellation Carina. It has a mean apparent magnitude of +8.55.
WR 25 is a binary star system in the turbulent star-forming region the Carina Nebula, about 6,800 light-years from Earth. It contains a Wolf-Rayet star and a hot luminous companion and is a member of the Trumpler 16 cluster. The name comes from the Catalogue of Galactic Wolf–Rayet Stars.
WR 24 is a Wolf-Rayet star in the constellation Carina. It is one of the most luminous stars known. At the edge of naked eye visibility it is also one of the brightest Wolf Rayet stars in the sky.
Trumpler 16 is a massive open cluster that is home to some of the most luminous stars in the Milky Way galaxy. It is situated within the Carina Nebula complex in the Carina–Sagittarius Arm, located approximately 9,270 ly (2,842 pc) from Earth. The cluster has one star visible to the naked eye from the tropics southward, Eta Carinae.
Trumpler 14 is an open cluster with a diameter of six light-years (1.8 pc), located within the inner regions of the Carina Nebula, approximately 8,980 light-years (2,753 pc) from Earth. Together with the nearby Trumpler 16, they are the main clusters of the Carina OB1 stellar association, which is the largest association in the Carina Nebula, although Trumpler 14 is not as massive or as large as Trumpler 16.
Carina OB1 is a giant OB association in the Carina Nebula, which is home to some of the most massive and luminous stars in the Milky Way Galaxy. It includes the young star clusters Collinder 228, NGC 3293, NGC 3324, IC 2581, Trumpler 14, Trumpler 15 and Trumpler 16, the last being the home of Eta Carinae. It also includes another massive and luminous star, HD 93129A. It is approximately 2,680 parsecs (8,700 ly) from Earth.
NGC 5617 is an open cluster in the constellation Centaurus. NGC 5617 forms a binary open cluster with Trumpler 22. It lies one degree west-northwest of Alpha Centauri.
Embedded stellar clusters, or simply embedded clusters (EC), are open clusters that are still surrounded by their progenitor molecular cloud. They are often areas of active star formation, giving rise to stellar objects that have similar ages and compositions. Because of the dense material that surrounds the stars, they appear obscured in visible light but can be observed using other sections of the electromagnetic spectrum, such as the near-infrared and X-rays that can see through the cloud material. In the Milky Way Galaxy, embedded clusters can mostly be found within the Galactic disk or near the Galactic Center where most of the star-formation activity is happening.
IC 2714 is an open cluster in the constellation Carina. It was discovered by James Dunlop in 1826. It is located approximately 4,000 light years away from Earth, in the Carina–Sagittarius Arm.
Collinder 228 is an open cluster within the southern part of the Carina Nebula NGC 3372, about 25' south of η Carinae. It is probably composed of stars which recently formed from the material in the nebula. QZ Carinae is the brightest member of Collinder 228 with an apparent magnitude between 6.16 and 6.49.
