Emission nebula | |
---|---|
Observation data: J2000 epoch | |
Right ascension | 00h 45m 10.9s [1] |
Declination | −73° 04′ 17″ [1] |
Apparent magnitude (V) | 15.0 [1] |
Apparent dimensions (V) | 1.10′ × 0.70′ [2] |
Constellation | Tucana |
NGC 249 is an emission nebula in the constellation Tucana. It was discovered on 5 September 1826 by the astronomer James Dunlop. [3]
The New General Catalogue of Nebulae and Clusters of Stars is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the Index Catalogues, describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use.
The Ring Nebula is a planetary nebula in the northern constellation of Lyra.[C] Such a nebula is formed when a star, during the last stages of its evolution before becoming a white dwarf, expels a vast luminous envelope of ionized gas into the surrounding interstellar space.
NGC 2264 is the designation number of the New General Catalogue that identifies two astronomical objects as a single object: the Cone Nebula, and the Christmas Tree Cluster. Two other objects are within this designation but not officially included, the Snowflake Cluster, and the Fox Fur Nebula. All of the objects are located in the Monoceros constellation and are located about 720 parsecs or 2,300 light-years from Earth. Due to its relative proximity and large size, it is extremely well-studied. NGC 2264 is sometimes referred to as the Christmas Tree Cluster and the Cone Nebula. However, the designation of NGC 2264 in the New General Catalogue refers to both objects and not the cluster alone. In December 2023, NASA released Christmas holiday-related images by the James Webb Space Telescope, including the Christmas Tree Galaxy Cluster and others.
Messier 102 is a galaxy listed in the Messier Catalogue that cannot be unambiguously identified. Its original discoverer Pierre Méchain retracted his discovery two years after publication and said that it was a duplicate observation of Messier 101. Later historical evidence favors that M102 is actually the galaxy NGC 5866, although other galaxies have been suggested as possible identities. The National Aeronautics and Space Administration (NASA) considers it to be the same as NGC 5866.
Messier 105 or M105, also known as NGC 3379, is an elliptical galaxy 36.6 million light-years away in the equatorial constellation of Leo. It is the biggest elliptical galaxy in the Messier catalogue that is not in the Virgo cluster. It was discovered by Pierre Méchain in 1781, just a few days after he discovered the nearby galaxies Messier 95 and Messier 96. This galaxy is one of a few not object-verified by Messier so omitted in the editions of his Catalogue of his era. It was appended when Helen S. Hogg found a letter by Méchain locating and describing this object which matched those aspects under its first-published name, NGC 3379.
NGC 6751, also known as the Glowing Eye Nebula, is a planetary nebula in the constellation Aquila. It is estimated to be about 6,500 light-years away.
NGC 1672 is a barred spiral galaxy located in the constellation Dorado. It was discovered by the astronomer James Dunlop on November 5, 1826. It was originally unclear whether it was a member of the Dorado Group, with some sources finding it to be a member and other sources rejecting its membership. However, recent tip of the red-giant branch (TRGB) measurements indicate that NGC 1672 is located at the same distance as other members, suggesting it is indeed a member of the Dorado Group.
NGC 6210, sometimes also known as the Turtle Nebula, is a planetary nebula located in the constellation Hercules, approximately 5.4 ± 1.3 kly from the Sun. It is positioned about 38° above the galactic plane at a vertical distance of about 3.3 kilolight-years (1 kpc) and thus has little extinction from intervening interstellar dust. This object was first recorded as a star-like feature by Joseph Lalande on March 22, 1799. However, credit for the discovery of a nebula goes to Wilhelm Struve in 1825. John L. E. Dreyer described it as, "a planetary nebula, very bright, very small, round, disc and border".
NGC 2371-2 is a dual lobed planetary nebula located in the constellation Gemini. Visually, it appears like it could be two separate objects; therefore, two entries were given to the planetary nebula by John Louis Emil Dreyer in the New General Catalogue, so it may be referred to as NGC 2371, NGC 2372, or variations on this name. It has also been called the double bubble nebula.
NGC 5929 is a well-studied Seyfert galaxy in the constellation Boötes. It was discovered by English astronomer John Herschel on May 13, 1828. In the revised New General Catalogue it is described as "elongated, brighter toward the middle, with a slightly diffuse halo". This galaxy is located at an estimated distance of 133 million light-years. It forms an interacting pair with NGC 5930 at an angular separation of 0.5′; together they form entry number 90 in Halton Arp's 1966 Atlas of Peculiar Galaxies. A dust streak from NGC 5930 appears to lie in front of NGC 5929, suggesting that the former galaxy is the closer member of this pair.
NGC 5970 is a large barred-spiral galaxy located about 90 million light years away in the constellation Serpens Caput. It appears to have two satellite or companion galaxies. It is a member of the Virgo Cluster of galaxies. It was discovered on March 15, 1784, by the astronomer William Herschel.
NGC 65 is a lenticular galaxy in the constellation Cetus. Its apparent magnitude is 13.4. It was first discovered in 1886, and is also known as PGC 1229.
NGC 203 is a lenticular galaxy located approximately 233 million light-years from the Solar System in the constellation Pisces. It was discovered on December 19, 1873 by Ralph Copeland.
NGC 7075 is an elliptical galaxy with a radio emission located about 290 million light-years away in the constellation of Grus. NGC 7075 was discovered by astronomer John Herschel on September 4, 1834.
NGC 1624, also known as Sh2-212 in the Sharpless catalog, is a very young open cluster in the constellation Perseus inside an emission nebula. It was discovered by German-British astronomer William Herschel in 1790. NGC 1624 is about 20,000 ly from Earth, and latest estimates give it an age of less than 4 million years. Its apparent magnitude is 11.8, and apparent diameter is about 3.0 arc minutes. Its celestial location is right ascension (α) 04h 40m 36.0s and declination (δ) +50° 27′ 42″. It is potentially an area of massive star formation.
NGC 612 is a lenticular galaxy in the constellation of Sculptor located approximately 388 million light-years from Earth. It is a type II Seyfert galaxy and thus has an active galactic nucleus. NGC 612 has been identified as an extremely rare example of a non-elliptical radio galaxy, hosting one of the nearest powerful FR-II radio sources.
NGC 2336 is a barred spiral galaxy located in the constellation Camelopardalis. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2336 is about 200,000 light years across. It was discovered by Wilhelm Tempel in 1876.
NGC 600 is an emission-line galaxy in the constellation Cetus. It was discovered by William Herschel on 10 September 1785. The galaxy has a diameter of 70,000 light-years. It is also approximately 90 million light-years from the Milky Way.
NGC 3998 is a lenticular galaxy located in the constellation Ursa Major. It was discovered on April 14, 1789, by the astronomer William Herschel. At a distance of 45 million light-years, it is located relatively nearby, making it a well-studied object.