The Eskimo Nebula, also known as the Clown-faced Nebula, Lion Nebula, or Caldwell 39, is a bipolar double-shell planetary nebula (PN). It was discovered by astronomer William Herschel in 1787. The formation resembles a person's head surrounded by a parka hood. It is surrounded by gas that composed the outer layers of a Sun-like star. The visible inner filaments are ejected by a strong wind of particles from the central star. The outer disk contains unusual, light-year-long filaments.
Winnecke 4 is an optical double star consisting of two unrelated stars in a northerly zone of the sky, Ursa Major.
NGC 2438 is a planetary nebula in the southern constellation of Puppis. Parallax measurements by Gaia put the central star at a distance of roughly 1,370 light years. It was discovered by William Herschel on March 19, 1786. NGC 2438 appears to lie within the cluster M46, but it is most likely unrelated since it does not share the cluster's radial velocity. The case is yet another example of a superposed pair, joining the famed case of NGC 2818.
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 smaller, hot star with a temperature on the surface of about 50,000 degrees Celsius. Radiation from the star causes the shed outer layer to heat to about 10,000 degrees Celsius, and 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 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.
NGC 2022 is a planetary nebula in the equatorial constellation of Orion, located at a distance of 8.21 kilolight-years from the Sun. It was first observed by William Herschel on December 28, 1785, who described it as: considerably bright, nearly round, like a star with a large diameter, like an ill-defined planetary nebula. In medium-sized amateur telescopes it looks like a small grayish patch of light. It is not very bright but it is still easy to spot it in the eyepiece. Even in a telescope as small as 80mm it can just be seen using a narrowband filter such as an OIII filter as a 'fuzzy' star. The object has the shape of a prolate spheroid with a major to minor axis ratio of 1.2, an apparent size of 28″, and a halo extending out to 40″, which is about the angular diameter of Jupiter as seen from Earth.
NGC 5307 is a planetary nebula in the southern constellation of Centaurus, positioned less than 3° to the northeast of the star Epsilon Centauri. It was discovered by English astronomer John Herschel on April 15, 1836. The nebula is located at a distance of approximately 10.6 kilolight-years from the Sun. The central star, designated PNG 312.3+10.5, is a weak emission-line star, superficially similar to the WC subtype of Wolf–Rayet stars. It has a spectral class of O(H)3.5 V.
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 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 6884 is a planetary nebula located in the constellation Cygnus, less than a degree to the southwest of the star Ο1 Cygni. It lies at a distance of approximately 12.5 kly from the Sun. The nebula was discovered on May 8, 1883, by American astronomer Edward C. Pickering.
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 3242 is a planetary nebula located in the constellation Hydra.
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.
NGC 1535 is a planetary nebula in the constellation of Eridanus, discovered by William Herschel on February 1, 1785. It is very similar to the Eskimo Nebula in both color and structure but the central star can be quite difficult to observe visually.
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, Turquoise Orb.
NGC 1501 is a complex planetary nebula located in the constellation of Camelopardalis, it was discovered on the 27th August 1787 by William Herschel. It is also known as the Oyster Nebula.
NGC 6309, also known as the Box Nebula, is a planetary nebula located in the constellation Ophiuchus. It was discovered by the German astronomer Wilhelm Tempel in 1876. It has a luminosity of about 1800 times that of the Sun. The distance to this nebula is not well known, but it is assumed to be about 6,500 light-years or 2,000 parsecs.
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.
Abell 48 is a planetary nebula likely located around 14,000 light years away in the constellation of Aquila. It is noteworthy among planetary nebulae for hosting a rare WN-type Wolf-Rayet-type central star, a [WN4]-type star, which was once thought to be a bona-fide Wolf-Rayet star, and received the name WR 120–6. The nebula is made up of two rings surrounding the central star, and is heavily reddened, with an E(B-V) value of 2.14 and a visual extinction of 6.634 magnitudes, which is why it appears so dim.
Hubble Space Telescope image of NGC 7662 [8]
