NGC 2346 is a planetary nebula near the celestial equator in the constellation of Monoceros, less than a degree to the ESE of Delta Monocerotis. It is informally known as the Butterfly Nebula. The nebula is bright and conspicuous with a visual magnitude of 9.6, and has been extensively studied. Among its most remarkable characteristics is its unusually cool central star, which is a spectroscopic binary, and its unusual shape.
NGC 40 is a planetary nebula discovered by William Herschel on November 25, 1788, and is composed of hot gas around a dying star. The star has ejected its outer layer which has left behind a small, hot star. Radiation from the star causes the shed outer layer to heat to about 10,000 degrees Celsius and become visible as a planetary nebula. The nebula is about one light-year across. About 30,000 years from now, scientists theorize that NGC 40 will fade away, leaving only a white dwarf star approximately the size of Earth.
NGC 6781, also known as the Snowglobe Nebula, is a planetary nebula located in the equatorial constellation of Aquila, about 2.5° east-northeast of the 5th magnitude star 19 Aquilae. It was discovered July 30, 1788 by the Anglo-German astronomer William Herschel. The nebula lies at a distance of 1,500 ly from the Sun. It has a visual magnitude of 11.4 and spans an angular size of 1.9 × 1.8 arcminutes.
IC 4406, sometimes known as the Retina Nebula, is a planetary nebula near the western border of the constellation Lupus, the Wolf. It has dust clouds and has the shape of a torus. Despite this, it looks somewhat rectangular because it is seen from its side as viewed from Earth, almost in the plane of its equator.
NGC 6578 is a planetary nebula located in Sagittarius. It is magnitude 13.5 with diameter 8 arc seconds. It has a 16th magnitude central star, which is an O-type star with a spectral type of Of. It is seen near the star 16 Sagittarii.
NGC 7662 is a planetary nebula located in the northern constellation Andromeda. It is known as the Blue Snowball Nebula, Snowball Nebula, and Caldwell 22. This nebula was discovered October 6, 1784 by the German-born English astronomer William Herschel. In the New General Catalogue it is described as a "magnificent planetary or annular nebula, very bright, pretty small in angular size, round, blue, variable nucleus". The object has an apparent visual magnitude of 8.3 and spans an angular size of 32″ × 28″. Parallax measurements give a distance estimate of 5,730 ± 340 ly (1,757 ± 103 pc).
NGC 7354 is a planetary nebula located in the northern circumpolar constellation of Cepheus, at a distance of approximately 5.5 kly from the Sun. It was discovered by German-born astronomer William Herschel on November 3, 1787. John L. E. Dreyer described it as, "a planetary nebula, bright, small, round, pretty gradually a very little brighter middle".
NGC 3195 is a planetary nebula located in the southern constellation of Chamaeleon. Discovered by Sir John Herschel in 1835, this 11.6 apparent magnitude planetary nebula is slightly oval in shape, with dimensions of 40×35 arc seconds, and can be seen visually in telescopic apertures of 10.5 centimetres (4.1 in) at low magnifications.
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.
WR 136 is a Wolf–Rayet star located in the constellation Cygnus. It is in the center of the Crescent Nebula. Its age is estimated to be around 4.7 million years and it is nearing the end of its life. Within a few hundred thousand years, it is expected to explode as a supernova.
NGC 6072 is a planetary nebulae in the southern constellation of Scorpius. It has a dynamical age of 104 years. Its circumstellar envelope is likely to be rich in carbon as it has very strong CN (cyanide) spectral lines. CN spectral lines are generally not detected in oxygen rich AGB (asymptotic giant branch) circumstellar envelopes. NGC 6072 also shows H2 (hydrogen) emission and intense CO (carbon monoxide) emission which has been mapped displaying bipolarity and some gas at high velocity. The evolution of this planetary nebulae is likely to be dominated by photodissociation and ion/radical molecular reactions. Shock chemistry is also likely to be important.
IC 2448 is an elliptical planetary nebula in the constellation of Carina. It was discovered in 1898 by Williamina Fleming. It lies near the bright star Beta Carinae, and the southern Carina can be explored in the months of autumn in the southern hemisphere. The central star of the planetary nebula is an O-type star with a spectral type of O(H)3 III-V. An analysis of Gaia data suggests that it is a binary system.
Little Ghost Nebula, also known as NGC 6369, is a planetary nebula in the constellation Ophiuchus. It was discovered by William Herschel.
NGC 6572 is a planetary nebula with magnitude 8.1, easily bright enough to make it an appealing target for amateur astronomers with telescopes. NGC 6572 is a young planetary nebula. NGC 6572 began to shed its gases a few thousand years ago. Because of this, the material is still quite concentrated, which explains its abnormal brightness. The envelope of gas is currently racing out into space at a speed of around 15 kilometres per second. As it becomes more diffuse, it will dim. It is located within the large constellation of Ophiuchus and at low magnification, it will appear to be just a colored star, but higher magnification will reveal its shape. NGC 6572 was discovered in 1825 by the German astronomer Friedrich Georg Wilhelm von Struve. According to several sources such as Sky & Telescope, this object received the nicknames Blue Racquetball, Emerald Nebula, Green Nebula, and Turquoise Orb.
IC 1295 is a planetary nebula in the constellation Scutum. It was discovered in 1867 by Truman Safford. It lies roughly 4,700 light-years away.
NGC 7026 is a planetary nebula located 6000 light-years away, in the constellation of Cygnus. The central star of the planetary nebula has a spectral type of [WO3], indicating a spectrum similar to that of an oxygen-rich Wolf–Rayet star. An analysis of Gaia data suggests that it is a binary system.
NGC 6153 is a planetary nebula in the constellation Scorpius. It was discovered in 1883 by Ralph Copeland.
Abell 78 is a planetary nebula located in the constellation of Cygnus. It has a fainter halo consisting mostly hydrogen, and an inner elliptical ring that is mostly made of helium.
NGC 6905, also known as the Blue Flash Nebula, is a planetary nebula in the constellation Delphinus. It was discovered by William Herschel in 1784. The central star is 14.0 mag. The distance of the nebula, as with most planetary nebulae, is not well determined and estimates range between 1.7 and 2.6 kpc.
WR 31a, commonly referred to as Hen 3-519, is a Wolf–Rayet (WR) star in the southern constellation of Carina that is surrounded by an expanding Wolf–Rayet nebula. It is not a classical old stripped-envelope WR star, but a young massive star which still has some hydrogen left in its atmosphere.
